diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/amba-pl022.c | 1866 |
3 files changed, 1876 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 7c61251..8e7c17e 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -171,6 +171,15 @@ config SPI_ORION help This enables using the SPI master controller on the Orion chips. +config SPI_PL022 + tristate "ARM AMBA PL022 SSP controller (EXPERIMENTAL)" + depends on ARM_AMBA && EXPERIMENTAL + default y if MACH_U300 + help + This selects the ARM(R) AMBA(R) PrimeCell PL022 SSP + controller. If you have an embedded system with an AMBA(R) + bus and a PL022 controller, say Y or M here. + config SPI_PXA2XX tristate "PXA2xx SSP SPI master" depends on ARCH_PXA && EXPERIMENTAL diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 5d04519..ecfadb1 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o obj-$(CONFIG_SPI_ORION) += orion_spi.o +obj-$(CONFIG_SPI_PL022) += amba-pl022.o obj-$(CONFIG_SPI_MPC52xx_PSC) += mpc52xx_psc_spi.o obj-$(CONFIG_SPI_MPC83xx) += spi_mpc83xx.o obj-$(CONFIG_SPI_S3C24XX_GPIO) += spi_s3c24xx_gpio.o diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c new file mode 100644 index 0000000..da76797 --- /dev/null +++ b/drivers/spi/amba-pl022.c @@ -0,0 +1,1866 @@ +/* + * drivers/spi/amba-pl022.c + * + * A driver for the ARM PL022 PrimeCell SSP/SPI bus master. + * + * Copyright (C) 2008-2009 ST-Ericsson AB + * Copyright (C) 2006 STMicroelectronics Pvt. Ltd. + * + * Author: Linus Walleij <linus.walleij@stericsson.com> + * + * Initial version inspired by: + * linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c + * Initial adoption to PL022 by: + * Sachin Verma <sachin.verma@st.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +/* + * TODO: + * - add timeout on polled transfers + * - add generic DMA framework support + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/ioport.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/spi/spi.h> +#include <linux/workqueue.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/amba/bus.h> +#include <linux/amba/pl022.h> +#include <linux/io.h> +#include <linux/delay.h> + +/* + * This macro is used to define some register default values. + * reg is masked with mask, the OR:ed with an (again masked) + * val shifted sb steps to the left. + */ +#define SSP_WRITE_BITS(reg, val, mask, sb) \ + ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask)))) + +/* + * This macro is also used to define some default values. + * It will just shift val by sb steps to the left and mask + * the result with mask. + */ +#define GEN_MASK_BITS(val, mask, sb) \ + (((val)<<(sb)) & (mask)) + +#define DRIVE_TX 0 +#define DO_NOT_DRIVE_TX 1 + +#define DO_NOT_QUEUE_DMA 0 +#define QUEUE_DMA 1 + +#define RX_TRANSFER 1 +#define TX_TRANSFER 2 + +/* + * Macros to access SSP Registers with their offsets + */ +#define SSP_CR0(r) (r + 0x000) +#define SSP_CR1(r) (r + 0x004) +#define SSP_DR(r) (r + 0x008) +#define SSP_SR(r) (r + 0x00C) +#define SSP_CPSR(r) (r + 0x010) +#define SSP_IMSC(r) (r + 0x014) +#define SSP_RIS(r) (r + 0x018) +#define SSP_MIS(r) (r + 0x01C) +#define SSP_ICR(r) (r + 0x020) +#define SSP_DMACR(r) (r + 0x024) +#define SSP_ITCR(r) (r + 0x080) +#define SSP_ITIP(r) (r + 0x084) +#define SSP_ITOP(r) (r + 0x088) +#define SSP_TDR(r) (r + 0x08C) + +#define SSP_PID0(r) (r + 0xFE0) +#define SSP_PID1(r) (r + 0xFE4) +#define SSP_PID2(r) (r + 0xFE8) +#define SSP_PID3(r) (r + 0xFEC) + +#define SSP_CID0(r) (r + 0xFF0) +#define SSP_CID1(r) (r + 0xFF4) +#define SSP_CID2(r) (r + 0xFF8) +#define SSP_CID3(r) (r + 0xFFC) + +/* + * SSP Control Register 0 - SSP_CR0 + */ +#define SSP_CR0_MASK_DSS (0x1FUL << 0) +#define SSP_CR0_MASK_HALFDUP (0x1UL << 5) +#define SSP_CR0_MASK_SPO (0x1UL << 6) +#define SSP_CR0_MASK_SPH (0x1UL << 7) +#define SSP_CR0_MASK_SCR (0xFFUL << 8) +#define SSP_CR0_MASK_CSS (0x1FUL << 16) +#define SSP_CR0_MASK_FRF (0x3UL << 21) + +/* + * SSP Control Register 0 - SSP_CR1 + */ +#define SSP_CR1_MASK_LBM (0x1UL << 0) +#define SSP_CR1_MASK_SSE (0x1UL << 1) +#define SSP_CR1_MASK_MS (0x1UL << 2) +#define SSP_CR1_MASK_SOD (0x1UL << 3) +#define SSP_CR1_MASK_RENDN (0x1UL << 4) +#define SSP_CR1_MASK_TENDN (0x1UL << 5) +#define SSP_CR1_MASK_MWAIT (0x1UL << 6) +#define SSP_CR1_MASK_RXIFLSEL (0x7UL << 7) +#define SSP_CR1_MASK_TXIFLSEL (0x7UL << 10) + +/* + * SSP Data Register - SSP_DR + */ +#define SSP_DR_MASK_DATA 0xFFFFFFFF + +/* + * SSP Status Register - SSP_SR + */ +#define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */ +#define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */ +#define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */ +#define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */ +#define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */ + +/* + * SSP Clock Prescale Register - SSP_CPSR + */ +#define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0) + +/* + * SSP Interrupt Mask Set/Clear Register - SSP_IMSC + */ +#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */ +#define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */ +#define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */ +#define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */ + +/* + * SSP Raw Interrupt Status Register - SSP_RIS + */ +/* Receive Overrun Raw Interrupt status */ +#define SSP_RIS_MASK_RORRIS (0x1UL << 0) +/* Receive Timeout Raw Interrupt status */ +#define SSP_RIS_MASK_RTRIS (0x1UL << 1) +/* Receive FIFO Raw Interrupt status */ +#define SSP_RIS_MASK_RXRIS (0x1UL << 2) +/* Transmit FIFO Raw Interrupt status */ +#define SSP_RIS_MASK_TXRIS (0x1UL << 3) + +/* + * SSP Masked Interrupt Status Register - SSP_MIS + */ +/* Receive Overrun Masked Interrupt status */ +#define SSP_MIS_MASK_RORMIS (0x1UL << 0) +/* Receive Timeout Masked Interrupt status */ +#define SSP_MIS_MASK_RTMIS (0x1UL << 1) +/* Receive FIFO Masked Interrupt status */ +#define SSP_MIS_MASK_RXMIS (0x1UL << 2) +/* Transmit FIFO Masked Interrupt status */ +#define SSP_MIS_MASK_TXMIS (0x1UL << 3) + +/* + * SSP Interrupt Clear Register - SSP_ICR + */ +/* Receive Overrun Raw Clear Interrupt bit */ +#define SSP_ICR_MASK_RORIC (0x1UL << 0) +/* Receive Timeout Clear Interrupt bit */ +#define SSP_ICR_MASK_RTIC (0x1UL << 1) + +/* + * SSP DMA Control Register - SSP_DMACR + */ +/* Receive DMA Enable bit */ +#define SSP_DMACR_MASK_RXDMAE (0x1UL << 0) +/* Transmit DMA Enable bit */ +#define SSP_DMACR_MASK_TXDMAE (0x1UL << 1) + +/* + * SSP Integration Test control Register - SSP_ITCR + */ +#define SSP_ITCR_MASK_ITEN (0x1UL << 0) +#define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1) + +/* + * SSP Integration Test Input Register - SSP_ITIP + */ +#define ITIP_MASK_SSPRXD (0x1UL << 0) +#define ITIP_MASK_SSPFSSIN (0x1UL << 1) +#define ITIP_MASK_SSPCLKIN (0x1UL << 2) +#define ITIP_MASK_RXDMAC (0x1UL << 3) +#define ITIP_MASK_TXDMAC (0x1UL << 4) +#define ITIP_MASK_SSPTXDIN (0x1UL << 5) + +/* + * SSP Integration Test output Register - SSP_ITOP + */ +#define ITOP_MASK_SSPTXD (0x1UL << 0) +#define ITOP_MASK_SSPFSSOUT (0x1UL << 1) +#define ITOP_MASK_SSPCLKOUT (0x1UL << 2) +#define ITOP_MASK_SSPOEn (0x1UL << 3) +#define ITOP_MASK_SSPCTLOEn (0x1UL << 4) +#define ITOP_MASK_RORINTR (0x1UL << 5) +#define ITOP_MASK_RTINTR (0x1UL << 6) +#define ITOP_MASK_RXINTR (0x1UL << 7) +#define ITOP_MASK_TXINTR (0x1UL << 8) +#define ITOP_MASK_INTR (0x1UL << 9) +#define ITOP_MASK_RXDMABREQ (0x1UL << 10) +#define ITOP_MASK_RXDMASREQ (0x1UL << 11) +#define ITOP_MASK_TXDMABREQ (0x1UL << 12) +#define ITOP_MASK_TXDMASREQ (0x1UL << 13) + +/* + * SSP Test Data Register - SSP_TDR + */ +#define TDR_MASK_TESTDATA (0xFFFFFFFF) + +/* + * Message State + * we use the spi_message.state (void *) pointer to + * hold a single state value, that's why all this + * (void *) casting is done here. + */ +#define STATE_START ((void *) 0) +#define STATE_RUNNING ((void *) 1) +#define STATE_DONE ((void *) 2) +#define STATE_ERROR ((void *) -1) + +/* + * Queue State + */ +#define QUEUE_RUNNING (0) +#define QUEUE_STOPPED (1) +/* + * SSP State - Whether Enabled or Disabled + */ +#define SSP_DISABLED (0) +#define SSP_ENABLED (1) + +/* + * SSP DMA State - Whether DMA Enabled or Disabled + */ +#define SSP_DMA_DISABLED (0) +#define SSP_DMA_ENABLED (1) + +/* + * SSP Clock Defaults + */ +#define NMDK_SSP_DEFAULT_CLKRATE 0x2 +#define NMDK_SSP_DEFAULT_PRESCALE 0x40 + +/* + * SSP Clock Parameter ranges + */ +#define CPSDVR_MIN 0x02 +#define CPSDVR_MAX 0xFE +#define SCR_MIN 0x00 +#define SCR_MAX 0xFF + +/* + * SSP Interrupt related Macros + */ +#define DEFAULT_SSP_REG_IMSC 0x0UL +#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC +#define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC) + +#define CLEAR_ALL_INTERRUPTS 0x3 + + +/* + * The type of reading going on on this chip + */ +enum ssp_reading { + READING_NULL, + READING_U8, + READING_U16, + READING_U32 +}; + +/** + * The type of writing going on on this chip + */ +enum ssp_writing { + WRITING_NULL, + WRITING_U8, + WRITING_U16, + WRITING_U32 +}; + +/** + * struct vendor_data - vendor-specific config parameters + * for PL022 derivates + * @fifodepth: depth of FIFOs (both) + * @max_bpw: maximum number of bits per word + * @unidir: supports unidirection transfers + */ +struct vendor_data { + int fifodepth; + int max_bpw; + bool unidir; +}; + +/** + * struct pl022 - This is the private SSP driver data structure + * @adev: AMBA device model hookup + * @phybase: The physical memory where the SSP device resides + * @virtbase: The virtual memory where the SSP is mapped + * @master: SPI framework hookup + * @master_info: controller-specific data from machine setup + * @regs: SSP controller register's virtual address + * @pump_messages: Work struct for scheduling work to the workqueue + * @lock: spinlock to syncronise access to driver data + * @workqueue: a workqueue on which any spi_message request is queued + * @busy: workqueue is busy + * @run: workqueue is running + * @pump_transfers: Tasklet used in Interrupt Transfer mode + * @cur_msg: Pointer to current spi_message being processed + * @cur_transfer: Pointer to current spi_transfer + * @cur_chip: pointer to current clients chip(assigned from controller_state) + * @tx: current position in TX buffer to be read + * @tx_end: end position in TX buffer to be read + * @rx: current position in RX buffer to be written + * @rx_end: end position in RX buffer to be written + * @readingtype: the type of read currently going on + * @writingtype: the type or write currently going on + */ +struct pl022 { + struct amba_device *adev; + struct vendor_data *vendor; + resource_size_t phybase; + void __iomem *virtbase; + struct clk *clk; + struct spi_master *master; + struct pl022_ssp_controller *master_info; + /* Driver message queue */ + struct workqueue_struct *workqueue; + struct work_struct pump_messages; + spinlock_t queue_lock; + struct list_head queue; + int busy; + int run; + /* Message transfer pump */ + struct tasklet_struct pump_transfers; + struct spi_message *cur_msg; + struct spi_transfer *cur_transfer; + struct chip_data *cur_chip; + void *tx; + void *tx_end; + void *rx; + void *rx_end; + enum ssp_reading read; + enum ssp_writing write; +}; + +/** + * struct chip_data - To maintain runtime state of SSP for each client chip + * @cr0: Value of control register CR0 of SSP + * @cr1: Value of control register CR1 of SSP + * @dmacr: Value of DMA control Register of SSP + * @cpsr: Value of Clock prescale register + * @n_bytes: how many bytes(power of 2) reqd for a given data width of client + * @enable_dma: Whether to enable DMA or not + * @write: function ptr to be used to write when doing xfer for this chip + * @read: function ptr to be used to read when doing xfer for this chip + * @cs_control: chip select callback provided by chip + * @xfer_type: polling/interrupt/DMA + * + * Runtime state of the SSP controller, maintained per chip, + * This would be set according to the current message that would be served + */ +struct chip_data { + u16 cr0; + u16 cr1; + u16 dmacr; + u16 cpsr; + u8 n_bytes; + u8 enable_dma:1; + enum ssp_reading read; + enum ssp_writing write; + void (*cs_control) (u32 command); + int xfer_type; +}; + +/** + * null_cs_control - Dummy chip select function + * @command: select/delect the chip + * + * If no chip select function is provided by client this is used as dummy + * chip select + */ +static void null_cs_control(u32 command) +{ + pr_debug("pl022: dummy chip select control, CS=0x%x\n", command); +} + +/** + * giveback - current spi_message is over, schedule next message and call + * callback of this message. Assumes that caller already + * set message->status; dma and pio irqs are blocked + * @pl022: SSP driver private data structure + */ +static void giveback(struct pl022 *pl022) +{ + struct spi_transfer *last_transfer; + unsigned long flags; + struct spi_message *msg; + void (*curr_cs_control) (u32 command); + + /* + * This local reference to the chip select function + * is needed because we set curr_chip to NULL + * as a step toward termininating the message. + */ + curr_cs_control = pl022->cur_chip->cs_control; + spin_lock_irqsave(&pl022->queue_lock, flags); + msg = pl022->cur_msg; + pl022->cur_msg = NULL; + pl022->cur_transfer = NULL; + pl022->cur_chip = NULL; + queue_work(pl022->workqueue, &pl022->pump_messages); + spin_unlock_irqrestore(&pl022->queue_lock, flags); + + last_transfer = list_entry(msg->transfers.prev, + struct spi_transfer, + transfer_list); + + /* Delay if requested before any change in chip select */ + if (last_transfer->delay_usecs) + /* + * FIXME: This runs in interrupt context. + * Is this really smart? + */ + udelay(last_transfer->delay_usecs); + + /* + * Drop chip select UNLESS cs_change is true or we are returning + * a message with an error, or next message is for another chip + */ + if (!last_transfer->cs_change) + curr_cs_control(SSP_CHIP_DESELECT); + else { + struct spi_message *next_msg; + + /* Holding of cs was hinted, but we need to make sure + * the next message is for the same chip. Don't waste + * time with the following tests unless this was hinted. + * + * We cannot postpone this until pump_messages, because + * after calling msg->complete (below) the driver that + * sent the current message could be unloaded, which + * could invalidate the cs_control() callback... + */ + + /* get a pointer to the next message, if any */ + spin_lock_irqsave(&pl022->queue_lock, flags); + if (list_empty(&pl022->queue)) + next_msg = NULL; + else + next_msg = list_entry(pl022->queue.next, + struct spi_message, queue); + spin_unlock_irqrestore(&pl022->queue_lock, flags); + + /* see if the next and current messages point + * to the same chip + */ + if (next_msg && next_msg->spi != msg->spi) + next_msg = NULL; + if (!next_msg || msg->state == STATE_ERROR) + curr_cs_control(SSP_CHIP_DESELECT); + } + msg->state = NULL; + if (msg->complete) + msg->complete(msg->context); + /* This message is completed, so let's turn off the clock! */ + clk_disable(pl022->clk); +} + +/** + * flush - flush the FIFO to reach a clean state + * @pl022: SSP driver private data structure + */ +static int flush(struct pl022 *pl022) +{ + unsigned long limit = loops_per_jiffy << 1; + + dev_dbg(&pl022->adev->dev, "flush\n"); + do { + while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) + readw(SSP_DR(pl022->virtbase)); + } while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--); + return limit; +} + +/** + * restore_state - Load configuration of current chip + * @pl022: SSP driver private data structure + */ +static void restore_state(struct pl022 *pl022) +{ + struct chip_data *chip = pl022->cur_chip; + + writew(chip->cr0, SSP_CR0(pl022->virtbase)); + writew(chip->cr1, SSP_CR1(pl022->virtbase)); + writew(chip->dmacr, SSP_DMACR(pl022->virtbase)); + writew(chip->cpsr, SSP_CPSR(pl022->virtbase)); + writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); +} + +/** + * load_ssp_default_config - Load default configuration for SSP + * @pl022: SSP driver private data structure + */ + +/* + * Default SSP Register Values + */ +#define DEFAULT_SSP_REG_CR0 ( \ + GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \ + GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP, 5) | \ + GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \ + GEN_MASK_BITS(SSP_CLK_FALLING_EDGE, SSP_CR0_MASK_SPH, 7) | \ + GEN_MASK_BITS(NMDK_SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \ + GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS, 16) | \ + GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 21) \ +) + +#define DEFAULT_SSP_REG_CR1 ( \ + GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \ + GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \ + GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \ + GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \ + GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN, 4) | \ + GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN, 5) | \ + GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT, 6) |\ + GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL, 7) | \ + GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL, 10) \ +) + +#define DEFAULT_SSP_REG_CPSR ( \ + GEN_MASK_BITS(NMDK_SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \ +) + +#define DEFAULT_SSP_REG_DMACR (\ + GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \ + GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \ +) + + +static void load_ssp_default_config(struct pl022 *pl022) +{ + writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase)); + writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase)); + writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase)); + writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase)); + writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); +} + +/** + * This will write to TX and read from RX according to the parameters + * set in pl022. + */ +static void readwriter(struct pl022 *pl022) +{ + + /* + * The FIFO depth is different inbetween primecell variants. + * I believe filling in too much in the FIFO might cause + * errons in 8bit wide transfers on ARM variants (just 8 words + * FIFO, means only 8x8 = 64 bits in FIFO) at least. + * + * FIXME: currently we have no logic to account for this. + * perhaps there is even something broken in HW regarding + * 8bit transfers (it doesn't fail on 16bit) so this needs + * more investigation... + */ + dev_dbg(&pl022->adev->dev, + "%s, rx: %p, rxend: %p, tx: %p, txend: %p\n", + __func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end); + + /* Read as much as you can */ + while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) + && (pl022->rx < pl022->rx_end)) { + switch (pl022->read) { + case READING_NULL: + readw(SSP_DR(pl022->virtbase)); + break; + case READING_U8: + *(u8 *) (pl022->rx) = + readw(SSP_DR(pl022->virtbase)) & 0xFFU; + break; + case READING_U16: + *(u16 *) (pl022->rx) = + (u16) readw(SSP_DR(pl022->virtbase)); + break; + case READING_U32: + *(u32 *) (pl022->rx) = + readl(SSP_DR(pl022->virtbase)); + break; + } + pl022->rx += (pl022->cur_chip->n_bytes); + } + /* + * Write as much as you can, while keeping an eye on the RX FIFO! + */ + while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF) + && (pl022->tx < pl022->tx_end)) { + switch (pl022->write) { + case WRITING_NULL: + writew(0x0, SSP_DR(pl022->virtbase)); + break; + case WRITING_U8: + writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase)); + break; + case WRITING_U16: + writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase)); + break; + case WRITING_U32: + writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase)); + break; + } + pl022->tx += (pl022->cur_chip->n_bytes); + /* + * This inner reader takes care of things appearing in the RX + * FIFO as we're transmitting. This will happen a lot since the + * clock starts running when you put things into the TX FIFO, + * and then things are continously clocked into the RX FIFO. + */ + while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) + && (pl022->rx < pl022->rx_end)) { + switch (pl022->read) { + case READING_NULL: + readw(SSP_DR(pl022->virtbase)); + break; + case READING_U8: + *(u8 *) (pl022->rx) = + readw(SSP_DR(pl022->virtbase)) & 0xFFU; + break; + case READING_U16: + *(u16 *) (pl022->rx) = + (u16) readw(SSP_DR(pl022->virtbase)); + break; + case READING_U32: + *(u32 *) (pl022->rx) = + readl(SSP_DR(pl022->virtbase)); + break; + } + pl022->rx += (pl022->cur_chip->n_bytes); + } + } + /* + * When we exit here the TX FIFO should be full and the RX FIFO + * should be empty + */ +} + + +/** + * next_transfer - Move to the Next transfer in the current spi message + * @pl022: SSP driver private data structure + * + * This function moves though the linked list of spi transfers in the + * current spi message and returns with the state of current spi + * message i.e whether its last transfer is done(STATE_DONE) or + * Next transfer is ready(STATE_RUNNING) + */ +static void *next_transfer(struct pl022 *pl022) +{ + struct spi_message *msg = pl022->cur_msg; + struct spi_transfer *trans = pl022->cur_transfer; + + /* Move to next transfer */ + if (trans->transfer_list.next != &msg->transfers) { + pl022->cur_transfer = + list_entry(trans->transfer_list.next, + struct spi_transfer, transfer_list); + return STATE_RUNNING; + } + return STATE_DONE; +} +/** + * pl022_interrupt_handler - Interrupt handler for SSP controller + * + * This function handles interrupts generated for an interrupt based transfer. + * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the + * current message's state as STATE_ERROR and schedule the tasklet + * pump_transfers which will do the postprocessing of the current message by + * calling giveback(). Otherwise it reads data from RX FIFO till there is no + * more data, and writes data in TX FIFO till it is not full. If we complete + * the transfer we move to the next transfer and schedule the tasklet. + */ +static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) +{ + struct pl022 *pl022 = dev_id; + struct spi_message *msg = pl022->cur_msg; + u16 irq_status = 0; + u16 flag = 0; + + if (unlikely(!msg)) { + dev_err(&pl022->adev->dev, + "bad message state in interrupt handler"); + /* Never fail */ + return IRQ_HANDLED; + } + + /* Read the Interrupt Status Register */ + irq_status = readw(SSP_MIS(pl022->virtbase)); + + if (unlikely(!irq_status)) + return IRQ_NONE; + + /* This handles the error code interrupts */ + if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) { + /* + * Overrun interrupt - bail out since our Data has been + * corrupted + */ + dev_err(&pl022->adev->dev, + "FIFO overrun\n"); + if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF) + dev_err(&pl022->adev->dev, + "RXFIFO is full\n"); + if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF) + dev_err(&pl022->adev->dev, + "TXFIFO is full\n"); + + /* + * Disable and clear interrupts, disable SSP, + * mark message with bad status so it can be + * retried. + */ + writew(DISABLE_ALL_INTERRUPTS, + SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); + writew((readw(SSP_CR1(pl022->virtbase)) & + (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase)); + msg->state = STATE_ERROR; + + /* Schedule message queue handler */ + tasklet_schedule(&pl022->pump_transfers); + return IRQ_HANDLED; + } + + readwriter(pl022); + + if ((pl022->tx == pl022->tx_end) && (flag == 0)) { + flag = 1; + /* Disable Transmit interrupt */ + writew(readw(SSP_IMSC(pl022->virtbase)) & + (~SSP_IMSC_MASK_TXIM), + SSP_IMSC(pl022->virtbase)); + } + + /* + * Since all transactions must write as much as shall be read, + * we can conclude the entire transaction once RX is complete. + * At this point, all TX will always be finished. + */ + if (pl022->rx >= pl022->rx_end) { + writew(DISABLE_ALL_INTERRUPTS, + SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); + if (unlikely(pl022->rx > pl022->rx_end)) { + dev_warn(&pl022->adev->dev, "read %u surplus " + "bytes (did you request an odd " + "number of bytes on a 16bit bus?)\n", + (u32) (pl022->rx - pl022->rx_end)); + } + /* Update total bytes transfered */ + msg->actual_length += pl022->cur_transfer->len; + if (pl022->cur_transfer->cs_change) + pl022->cur_chip-> + cs_control(SSP_CHIP_DESELECT); + /* Move to next transfer */ + msg->state = next_transfer(pl022); + tasklet_schedule(&pl022->pump_transfers); + return IRQ_HANDLED; + } + + return IRQ_HANDLED; +} + +/** + * This sets up the pointers to memory for the next message to + * send out on the SPI bus. + */ +static int set_up_next_transfer(struct pl022 *pl022, + struct spi_transfer *transfer) +{ + int residue; + + /* Sanity check the message for this bus width */ + residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes; + if (unlikely(residue != 0)) { + dev_err(&pl022->adev->dev, + "message of %u bytes to transmit but the current " + "chip bus has a data width of %u bytes!\n", + pl022->cur_transfer->len, + pl022->cur_chip->n_bytes); + dev_err(&pl022->adev->dev, "skipping this message\n"); + return -EIO; + } + pl022->tx = (void *)transfer->tx_buf; + pl022->tx_end = pl022->tx + pl022->cur_transfer->len; + pl022->rx = (void *)transfer->rx_buf; + pl022->rx_end = pl022->rx + pl022->cur_transfer->len; + pl022->write = + pl022->tx ? pl022->cur_chip->write : WRITING_NULL; + pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL; + return 0; +} + +/** + * pump_transfers - Tasklet function which schedules next interrupt transfer + * when running in interrupt transfer mode. + * @data: SSP driver private data structure + * + */ +static void pump_transfers(unsigned long data) +{ + struct pl022 *pl022 = (struct pl022 *) data; + struct spi_message *message = NULL; + struct spi_transfer *transfer = NULL; + struct spi_transfer *previous = NULL; + + /* Get current state information */ + message = pl022->cur_msg; + transfer = pl022->cur_transfer; + + /* Handle for abort */ + if (message->state == STATE_ERROR) { + message->status = -EIO; + giveback(pl022); + return; + } + + /* Handle end of message */ + if (message->state == STATE_DONE) { + message->status = 0; + giveback(pl022); + return; + } + + /* Delay if requested at end of transfer before CS change */ + if (message->state == STATE_RUNNING) { + previous = list_entry(transfer->transfer_list.prev, + struct spi_transfer, + transfer_list); + if (previous->delay_usecs) + /* + * FIXME: This runs in interrupt context. + * Is this really smart? + */ + udelay(previous->delay_usecs); + + /* Drop chip select only if cs_change is requested */ + if (previous->cs_change) + pl022->cur_chip->cs_control(SSP_CHIP_SELECT); + } else { + /* STATE_START */ + message->state = STATE_RUNNING; + } + + if (set_up_next_transfer(pl022, transfer)) { + message->state = STATE_ERROR; + message->status = -EIO; + giveback(pl022); + return; + } + /* Flush the FIFOs and let's go! */ + flush(pl022); + writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); +} + +/** + * NOT IMPLEMENTED + * configure_dma - It configures the DMA pipes for DMA transfers + * @data: SSP driver's private data structure + * + */ +static int configure_dma(void *data) +{ + struct pl022 *pl022 = data; + dev_dbg(&pl022->adev->dev, "configure DMA\n"); + return -ENOTSUPP; +} + +/** + * do_dma_transfer - It handles transfers of the current message + * if it is DMA xfer. + * NOT FULLY IMPLEMENTED + * @data: SSP driver's private data structure + */ +static void do_dma_transfer(void *data) +{ + struct pl022 *pl022 = data; + + if (configure_dma(data)) { + dev_dbg(&pl022->adev->dev, "configuration of DMA Failed!\n"); + goto err_config_dma; + } + + /* TODO: Implememt DMA setup of pipes here */ + + /* Enable target chip, set up transfer */ + pl022->cur_chip->cs_control(SSP_CHIP_SELECT); + if (set_up_next_transfer(pl022, pl022->cur_transfer)) { + /* Error path */ + pl022->cur_msg->state = STATE_ERROR; + pl022->cur_msg->status = -EIO; + giveback(pl022); + return; + } + /* Enable SSP */ + writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), + SSP_CR1(pl022->virtbase)); + + /* TODO: Enable the DMA transfer here */ + return; + + err_config_dma: + pl022->cur_msg->state = STATE_ERROR; + pl022->cur_msg->status = -EIO; + giveback(pl022); + return; +} + +static void do_interrupt_transfer(void *data) +{ + struct pl022 *pl022 = data; + + /* Enable target chip */ + pl022->cur_chip->cs_control(SSP_CHIP_SELECT); + if (set_up_next_transfer(pl022, pl022->cur_transfer)) { + /* Error path */ + pl022->cur_msg->state = STATE_ERROR; + pl022->cur_msg->status = -EIO; + giveback(pl022); + return; + } + /* Enable SSP, turn on interrupts */ + writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), + SSP_CR1(pl022->virtbase)); + writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); +} + +static void do_polling_transfer(void *data) +{ + struct pl022 *pl022 = data; + struct spi_message *message = NULL; + struct spi_transfer *transfer = NULL; + struct spi_transfer *previous = NULL; + struct chip_data *chip; + + chip = pl022->cur_chip; + message = pl022->cur_msg; + + while (message->state != STATE_DONE) { + /* Handle for abort */ + if (message->state == STATE_ERROR) + break; + transfer = pl022->cur_transfer; + + /* Delay if requested at end of transfer */ + if (message->state == STATE_RUNNING) { + previous = + list_entry(transfer->transfer_list.prev, + struct spi_transfer, transfer_list); + if (previous->delay_usecs) + udelay(previous->delay_usecs); + if (previous->cs_change) + pl022->cur_chip->cs_control(SSP_CHIP_SELECT); + } else { + /* STATE_START */ + message->state = STATE_RUNNING; + pl022->cur_chip->cs_control(SSP_CHIP_SELECT); + } + + /* Configuration Changing Per Transfer */ + if (set_up_next_transfer(pl022, transfer)) { + /* Error path */ + message->state = STATE_ERROR; + break; + } + /* Flush FIFOs and enable SSP */ + flush(pl022); + writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), + SSP_CR1(pl022->virtbase)); + + dev_dbg(&pl022->adev->dev, "POLLING TRANSFER ONGOING ... \n"); + /* FIXME: insert a timeout so we don't hang here indefinately */ + while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) + readwriter(pl022); + + /* Update total byte transfered */ + message->actual_length += pl022->cur_transfer->len; + if (pl022->cur_transfer->cs_change) + pl022->cur_chip->cs_control(SSP_CHIP_DESELECT); + /* Move to next transfer */ + message->state = next_transfer(pl022); + } + + /* Handle end of message */ + if (message->state == STATE_DONE) + message->status = 0; + else + message->status = -EIO; + + giveback(pl022); + return; +} + +/** + * pump_messages - Workqueue function which processes spi message queue + * @data: pointer to private data of SSP driver + * + * This function checks if there is any spi message in the queue that + * needs processing and delegate control to appropriate function + * do_polling_transfer()/do_interrupt_transfer()/do_dma_transfer() + * based on the kind of the transfer + * + */ +static void pump_messages(struct work_struct *work) +{ + struct pl022 *pl022 = + container_of(work, struct pl022, pump_messages); + unsigned long flags; + + /* Lock queue and check for queue work */ + spin_lock_irqsave(&pl022->queue_lock, flags); + if (list_empty(&pl022->queue) || pl022->run == QUEUE_STOPPED) { + pl022->busy = 0; + spin_unlock_irqrestore(&pl022->queue_lock, flags); + return; + } + /* Make sure we are not already running a message */ + if (pl022->cur_msg) { + spin_unlock_irqrestore(&pl022->queue_lock, flags); + return; + } + /* Extract head of queue */ + pl022->cur_msg = + list_entry(pl022->queue.next, struct spi_message, queue); + + list_del_init(&pl022->cur_msg->queue); + pl022->busy = 1; + spin_unlock_irqrestore(&pl022->queue_lock, flags); + + /* Initial message state */ + pl022->cur_msg->state = STATE_START; + pl022->cur_transfer = list_entry(pl022->cur_msg->transfers.next, + struct spi_transfer, + transfer_list); + + /* Setup the SPI using the per chip configuration */ + pl022->cur_chip = spi_get_ctldata(pl022->cur_msg->spi); + /* + * We enable the clock here, then the clock will be disabled when + * giveback() is called in each method (poll/interrupt/DMA) + */ + clk_enable(pl022->clk); + restore_state(pl022); + flush(pl022); + + if (pl022->cur_chip->xfer_type == POLLING_TRANSFER) + do_polling_transfer(pl022); + else if (pl022->cur_chip->xfer_type == INTERRUPT_TRANSFER) + do_interrupt_transfer(pl022); + else + do_dma_transfer(pl022); +} + + +static int __init init_queue(struct pl022 *pl022) +{ + INIT_LIST_HEAD(&pl022->queue); + spin_lock_init(&pl022->queue_lock); + + pl022->run = QUEUE_STOPPED; + pl022->busy = 0; + + tasklet_init(&pl022->pump_transfers, + pump_transfers, (unsigned long)pl022); + + INIT_WORK(&pl022->pump_messages, pump_messages); + pl022->workqueue = create_singlethread_workqueue( + dev_name(pl022->master->dev.parent)); + if (pl022->workqueue == NULL) + return -EBUSY; + + return 0; +} + + +static int start_queue(struct pl022 *pl022) +{ + unsigned long flags; + + spin_lock_irqsave(&pl022->queue_lock, flags); + + if (pl022->run == QUEUE_RUNNING || pl022->busy) { + spin_unlock_irqrestore(&pl022->queue_lock, flags); + return -EBUSY; + } + + pl022->run = QUEUE_RUNNING; + pl022->cur_msg = NULL; + pl022->cur_transfer = NULL; + pl022->cur_chip = NULL; + spin_unlock_irqrestore(&pl022->queue_lock, flags); + + queue_work(pl022->workqueue, &pl022->pump_messages); + + return 0; +} + + +static int stop_queue(struct pl022 *pl022) +{ + unsigned long flags; + unsigned limit = 500; + int status = 0; + + spin_lock_irqsave(&pl022->queue_lock, flags); + + /* This is a bit lame, but is optimized for the common execution path. + * A wait_queue on the pl022->busy could be used, but then the common + * execution path (pump_messages) would be required to call wake_up or + * friends on every SPI message. Do this instead */ + pl022->run = QUEUE_STOPPED; + while (!list_empty(&pl022->queue) && pl022->busy && limit--) { + spin_unlock_irqrestore(&pl022->queue_lock, flags); + msleep(10); + spin_lock_irqsave(&pl022->queue_lock, flags); + } + + if (!list_empty(&pl022->queue) || pl022->busy) + status = -EBUSY; + + spin_unlock_irqrestore(&pl022->queue_lock, flags); + + return status; +} + +static int destroy_queue(struct pl022 *pl022) +{ + int status; + + status = stop_queue(pl022); + /* we are unloading the module or failing to load (only two calls + * to this routine), and neither call can handle a return value. + * However, destroy_workqueue calls flush_workqueue, and that will + * block until all work is done. If the reason that stop_queue + * timed out is that the work will never finish, then it does no + * good to call destroy_workqueue, so return anyway. */ + if (status != 0) + return status; + + destroy_workqueue(pl022->workqueue); + + return 0; +} + +static int verify_controller_parameters(struct pl022 *pl022, + struct pl022_config_chip *chip_info) +{ + if ((chip_info->lbm != LOOPBACK_ENABLED) + && (chip_info->lbm != LOOPBACK_DISABLED)) { + dev_err(chip_info->dev, + "loopback Mode is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI) + || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) { + dev_err(chip_info->dev, + "interface is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) && + (!pl022->vendor->unidir)) { + dev_err(chip_info->dev, + "unidirectional mode not supported in this " + "hardware version\n"); + return -EINVAL; + } + if ((chip_info->hierarchy != SSP_MASTER) + && (chip_info->hierarchy != SSP_SLAVE)) { + dev_err(chip_info->dev, + "hierarchy is configured incorrectly\n"); + return -EINVAL; + } + if (((chip_info->clk_freq).cpsdvsr < CPSDVR_MIN) + || ((chip_info->clk_freq).cpsdvsr > CPSDVR_MAX)) { + dev_err(chip_info->dev, + "cpsdvsr is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->endian_rx != SSP_RX_MSB) + && (chip_info->endian_rx != SSP_RX_LSB)) { + dev_err(chip_info->dev, + "RX FIFO endianess is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->endian_tx != SSP_TX_MSB) + && (chip_info->endian_tx != SSP_TX_LSB)) { + dev_err(chip_info->dev, + "TX FIFO endianess is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->data_size < SSP_DATA_BITS_4) + || (chip_info->data_size > SSP_DATA_BITS_32)) { + dev_err(chip_info->dev, + "DATA Size is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->com_mode != INTERRUPT_TRANSFER) + && (chip_info->com_mode != DMA_TRANSFER) + && (chip_info->com_mode != POLLING_TRANSFER)) { + dev_err(chip_info->dev, + "Communication mode is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->rx_lev_trig < SSP_RX_1_OR_MORE_ELEM) + || (chip_info->rx_lev_trig > SSP_RX_32_OR_MORE_ELEM)) { + dev_err(chip_info->dev, + "RX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->tx_lev_trig < SSP_TX_1_OR_MORE_EMPTY_LOC) + || (chip_info->tx_lev_trig > SSP_TX_32_OR_MORE_EMPTY_LOC)) { + dev_err(chip_info->dev, + "TX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + if (chip_info->iface == SSP_INTERFACE_MOTOROLA_SPI) { + if ((chip_info->clk_phase != SSP_CLK_RISING_EDGE) + && (chip_info->clk_phase != SSP_CLK_FALLING_EDGE)) { + dev_err(chip_info->dev, + "Clock Phase is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->clk_pol != SSP_CLK_POL_IDLE_LOW) + && (chip_info->clk_pol != SSP_CLK_POL_IDLE_HIGH)) { + dev_err(chip_info->dev, + "Clock Polarity is configured incorrectly\n"); + return -EINVAL; + } + } + if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) { + if ((chip_info->ctrl_len < SSP_BITS_4) + || (chip_info->ctrl_len > SSP_BITS_32)) { + dev_err(chip_info->dev, + "CTRL LEN is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO) + && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) { + dev_err(chip_info->dev, + "Wait State is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX) + && (chip_info->duplex != + SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) { + dev_err(chip_info->dev, + "DUPLEX is configured incorrectly\n"); + return -EINVAL; + } + } + if (chip_info->cs_control == NULL) { + dev_warn(chip_info->dev, + "Chip Select Function is NULL for this chip\n"); + chip_info->cs_control = null_cs_control; + } + return 0; +} + +/** + * pl022_transfer - transfer function registered to SPI master framework + * @spi: spi device which is requesting transfer + * @msg: spi message which is to handled is queued to driver queue + * + * This function is registered to the SPI framework for this SPI master + * controller. It will queue the spi_message in the queue of driver if + * the queue is not stopped and return. + */ +static int pl022_transfer(struct spi_device *spi, struct spi_message *msg) +{ + struct pl022 *pl022 = spi_master_get_devdata(spi->master); + unsigned long flags; + + spin_lock_irqsave(&pl022->queue_lock, flags); + + if (pl022->run == QUEUE_STOPPED) { + spin_unlock_irqrestore(&pl022->queue_lock, flags); + return -ESHUTDOWN; + } + msg->actual_length = 0; + msg->status = -EINPROGRESS; + msg->state = STATE_START; + + list_add_tail(&msg->queue, &pl022->queue); + if (pl022->run == QUEUE_RUNNING && !pl022->busy) + queue_work(pl022->workqueue, &pl022->pump_messages); + + spin_unlock_irqrestore(&pl022->queue_lock, flags); + return 0; +} + +static int calculate_effective_freq(struct pl022 *pl022, + int freq, + struct ssp_clock_params *clk_freq) +{ + /* Lets calculate the frequency parameters */ + u16 cpsdvsr = 2; + u16 scr = 0; + bool freq_found = false; + u32 rate; + u32 max_tclk; + u32 min_tclk; + + rate = clk_get_rate(pl022->clk); + /* cpsdvscr = 2 & scr 0 */ + max_tclk = (rate / (CPSDVR_MIN * (1 + SCR_MIN))); + /* cpsdvsr = 254 & scr = 255 */ + min_tclk = (rate / (CPSDVR_MAX * (1 + SCR_MAX))); + + if ((freq <= max_tclk) && (freq >= min_tclk)) { + while (cpsdvsr <= CPSDVR_MAX && !freq_found) { + while (scr <= SCR_MAX && !freq_found) { + if ((rate / + (cpsdvsr * (1 + scr))) > freq) + scr += 1; + else { + /* + * This bool is made true when + * effective frequency >= + * target frequency is found + */ + freq_found = true; + if ((rate / + (cpsdvsr * (1 + scr))) != freq) { + if (scr == SCR_MIN) { + cpsdvsr -= 2; + scr = SCR_MAX; + } else + scr -= 1; + } + } + } + if (!freq_found) { + cpsdvsr += 2; + scr = SCR_MIN; + } + } + if (cpsdvsr != 0) { + dev_dbg(&pl022->adev->dev, + "SSP Effective Frequency is %u\n", + (rate / (cpsdvsr * (1 + scr)))); + clk_freq->cpsdvsr = (u8) (cpsdvsr & 0xFF); + clk_freq->scr = (u8) (scr & 0xFF); + dev_dbg(&pl022->adev->dev, + "SSP cpsdvsr = %d, scr = %d\n", + clk_freq->cpsdvsr, clk_freq->scr); + } + } else { + dev_err(&pl022->adev->dev, + "controller data is incorrect: out of range frequency"); + return -EINVAL; + } + return 0; +} + +/** + * NOT IMPLEMENTED + * process_dma_info - Processes the DMA info provided by client drivers + * @chip_info: chip info provided by client device + * @chip: Runtime state maintained by the SSP controller for each spi device + * + * This function processes and stores DMA config provided by client driver + * into the runtime state maintained by the SSP controller driver + */ +static int process_dma_info(struct pl022_config_chip *chip_info, + struct chip_data *chip) +{ + dev_err(chip_info->dev, + "cannot process DMA info, DMA not implemented!\n"); + return -ENOTSUPP; +} + +/** + * pl022_setup - setup function registered to SPI master framework + * @spi: spi device which is requesting setup + * + * This function is registered to the SPI framework for this SPI master + * controller. If it is the first time when setup is called by this device, + * this function will initialize the runtime state for this chip and save + * the same in the device structure. Else it will update the runtime info + * with the updated chip info. Nothing is really being written to the + * controller hardware here, that is not done until the actual transfer + * commence. + */ + +/* FIXME: JUST GUESSING the spi->mode bits understood by this driver */ +#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \ + | SPI_LSB_FIRST | SPI_LOOP) + +static int pl022_setup(struct spi_device *spi) +{ + struct pl022_config_chip *chip_info; + struct chip_data *chip; + int status = 0; + struct pl022 *pl022 = spi_master_get_devdata(spi->master); + + if (spi->mode & ~MODEBITS) { + dev_dbg(&spi->dev, "unsupported mode bits %x\n", + spi->mode & ~MODEBITS); + return -EINVAL; + } + + if (!spi->max_speed_hz) + return -EINVAL; + + /* Get controller_state if one is supplied */ + chip = spi_get_ctldata(spi); + + if (chip == NULL) { + chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); + if (!chip) { + dev_err(&spi->dev, + "cannot allocate controller state\n"); + return -ENOMEM; + } + dev_dbg(&spi->dev, + "allocated memory for controller's runtime state\n"); + } + + /* Get controller data if one is supplied */ + chip_info = spi->controller_data; + + if (chip_info == NULL) { + /* spi_board_info.controller_data not is supplied */ + dev_dbg(&spi->dev, + "using default controller_data settings\n"); + + chip_info = + kzalloc(sizeof(struct pl022_config_chip), GFP_KERNEL); + + if (!chip_info) { + dev_err(&spi->dev, + "cannot allocate controller data\n"); + status = -ENOMEM; + goto err_first_setup; + } + + dev_dbg(&spi->dev, "allocated memory for controller data\n"); + + /* Pointer back to the SPI device */ + chip_info->dev = &spi->dev; + /* + * Set controller data default values: + * Polling is supported by default + */ + chip_info->lbm = LOOPBACK_DISABLED; + chip_info->com_mode = POLLING_TRANSFER; + chip_info->iface = SSP_INTERFACE_MOTOROLA_SPI; + chip_info->hierarchy = SSP_SLAVE; + chip_info->slave_tx_disable = DO_NOT_DRIVE_TX; + chip_info->endian_tx = SSP_TX_LSB; + chip_info->endian_rx = SSP_RX_LSB; + chip_info->data_size = SSP_DATA_BITS_12; + chip_info->rx_lev_trig = SSP_RX_1_OR_MORE_ELEM; + chip_info->tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC; + chip_info->clk_phase = SSP_CLK_FALLING_EDGE; + chip_info->clk_pol = SSP_CLK_POL_IDLE_LOW; + chip_info->ctrl_len = SSP_BITS_8; + chip_info->wait_state = SSP_MWIRE_WAIT_ZERO; + chip_info->duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX; + chip_info->cs_control = null_cs_control; + } else { + dev_dbg(&spi->dev, + "using user supplied controller_data settings\n"); + } + + /* + * We can override with custom divisors, else we use the board + * frequency setting + */ + if ((0 == chip_info->clk_freq.cpsdvsr) + && (0 == chip_info->clk_freq.scr)) { + status = calculate_effective_freq(pl022, + spi->max_speed_hz, + &chip_info->clk_freq); + if (status < 0) + goto err_config_params; + } else { + if ((chip_info->clk_freq.cpsdvsr % 2) != 0) + chip_info->clk_freq.cpsdvsr = + chip_info->clk_freq.cpsdvsr - 1; + } + status = verify_controller_parameters(pl022, chip_info); + if (status) { + dev_err(&spi->dev, "controller data is incorrect"); + goto err_config_params; + } + /* Now set controller state based on controller data */ + chip->xfer_type = chip_info->com_mode; + chip->cs_control = chip_info->cs_control; + + if (chip_info->data_size <= 8) { + dev_dbg(&spi->dev, "1 <= n <=8 bits per word\n"); + chip->n_bytes = 1; + chip->read = READING_U8; + chip->write = WRITING_U8; + } else if (chip_info->data_size <= 16) { + dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n"); + chip->n_bytes = 2; + chip->read = READING_U16; + chip->write = WRITING_U16; + } else { + if (pl022->vendor->max_bpw >= 32) { + dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n"); + chip->n_bytes = 4; + chip->read = READING_U32; + chip->write = WRITING_U32; + } else { + dev_err(&spi->dev, + "illegal data size for this controller!\n"); + dev_err(&spi->dev, + "a standard pl022 can only handle " + "1 <= n <= 16 bit words\n"); + goto err_config_params; + } + } + + /* Now Initialize all register settings required for this chip */ + chip->cr0 = 0; + chip->cr1 = 0; + chip->dmacr = 0; + chip->cpsr = 0; + if ((chip_info->com_mode == DMA_TRANSFER) + && ((pl022->master_info)->enable_dma)) { + chip->enable_dma = 1; + dev_dbg(&spi->dev, "DMA mode set in controller state\n"); + status = process_dma_info(chip_info, chip); + if (status < 0) + goto err_config_params; + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, + SSP_DMACR_MASK_RXDMAE, 0); + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, + SSP_DMACR_MASK_TXDMAE, 1); + } else { + chip->enable_dma = 0; + dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n"); + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED, + SSP_DMACR_MASK_RXDMAE, 0); + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED, + SSP_DMACR_MASK_TXDMAE, 1); + } + + chip->cpsr = chip_info->clk_freq.cpsdvsr; + + SSP_WRITE_BITS(chip->cr0, chip_info->data_size, SSP_CR0_MASK_DSS, 0); + SSP_WRITE_BITS(chip->cr0, chip_info->duplex, SSP_CR0_MASK_HALFDUP, 5); + SSP_WRITE_BITS(chip->cr0, chip_info->clk_pol, SSP_CR0_MASK_SPO, 6); + SSP_WRITE_BITS(chip->cr0, chip_info->clk_phase, SSP_CR0_MASK_SPH, 7); + SSP_WRITE_BITS(chip->cr0, chip_info->clk_freq.scr, SSP_CR0_MASK_SCR, 8); + SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len, SSP_CR0_MASK_CSS, 16); + SSP_WRITE_BITS(chip->cr0, chip_info->iface, SSP_CR0_MASK_FRF, 21); + SSP_WRITE_BITS(chip->cr1, chip_info->lbm, SSP_CR1_MASK_LBM, 0); + SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1); + SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2); + SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD, 3); + SSP_WRITE_BITS(chip->cr1, chip_info->endian_rx, SSP_CR1_MASK_RENDN, 4); + SSP_WRITE_BITS(chip->cr1, chip_info->endian_tx, SSP_CR1_MASK_TENDN, 5); + SSP_WRITE_BITS(chip->cr1, chip_info->wait_state, SSP_CR1_MASK_MWAIT, 6); + SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig, SSP_CR1_MASK_RXIFLSEL, 7); + SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig, SSP_CR1_MASK_TXIFLSEL, 10); + + /* Save controller_state */ + spi_set_ctldata(spi, chip); + return status; + err_config_params: + err_first_setup: + kfree(chip); + return status; +} + +/** + * pl022_cleanup - cleanup function registered to SPI master framework + * @spi: spi device which is requesting cleanup + * + * This function is registered to the SPI framework for this SPI master + * controller. It will free the runtime state of chip. + */ +static void pl022_cleanup(struct spi_device *spi) +{ + struct chip_data *chip = spi_get_ctldata(spi); + + spi_set_ctldata(spi, NULL); + kfree(chip); +} + + +static int __init +pl022_probe(struct amba_device *adev, struct amba_id *id) +{ + struct device *dev = &adev->dev; + struct pl022_ssp_controller *platform_info = adev->dev.platform_data; + struct spi_master *master; + struct pl022 *pl022 = NULL; /*Data for this driver */ + int status = 0; + + dev_info(&adev->dev, + "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid); + if (platform_info == NULL) { + dev_err(&adev->dev, "probe - no platform data supplied\n"); + status = -ENODEV; + goto err_no_pdata; + } + + /* Allocate master with space for data */ + master = spi_alloc_master(dev, sizeof(struct pl022)); + if (master == NULL) { + dev_err(&adev->dev, "probe - cannot alloc SPI master\n"); + status = -ENOMEM; + goto err_no_master; + } + + pl022 = spi_master_get_devdata(master); + pl022->master = master; + pl022->master_info = platform_info; + pl022->adev = adev; + pl022->vendor = id->data; + + /* + * Bus Number Which has been Assigned to this SSP controller + * on this board + */ + master->bus_num = platform_info->bus_id; + master->num_chipselect = platform_info->num_chipselect; + master->cleanup = pl022_cleanup; + master->setup = pl022_setup; + master->transfer = pl022_transfer; + + dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num); + + status = amba_request_regions(adev, NULL); + if (status) + goto err_no_ioregion; + + pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res)); + if (pl022->virtbase == NULL) { + status = -ENOMEM; + goto err_no_ioremap; + } + printk(KERN_INFO "pl022: mapped registers from 0x%08x to %p\n", + adev->res.start, pl022->virtbase); + + pl022->clk = clk_get(&adev->dev, NULL); + if (IS_ERR(pl022->clk)) { + status = PTR_ERR(pl022->clk); + dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n"); + goto err_no_clk; + } + + /* Disable SSP */ + clk_enable(pl022->clk); + writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)), + SSP_CR1(pl022->virtbase)); + load_ssp_default_config(pl022); + clk_disable(pl022->clk); + + status = request_irq(adev->irq[0], pl022_interrupt_handler, 0, "pl022", + pl022); + if (status < 0) { + dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status); + goto err_no_irq; + } + /* Initialize and start queue */ + status = init_queue(pl022); + if (status != 0) { + dev_err(&adev->dev, "probe - problem initializing queue\n"); + goto err_init_queue; + } + status = start_queue(pl022); + if (status != 0) { + dev_err(&adev->dev, "probe - problem starting queue\n"); + goto err_start_queue; + } + /* Register with the SPI framework */ + amba_set_drvdata(adev, pl022); + status = spi_register_master(master); + if (status != 0) { + dev_err(&adev->dev, + "probe - problem registering spi master\n"); + goto err_spi_register; + } + dev_dbg(dev, "probe succeded\n"); + return 0; + + err_spi_register: + err_start_queue: + err_init_queue: + destroy_queue(pl022); + free_irq(adev->irq[0], pl022); + err_no_irq: + clk_put(pl022->clk); + err_no_clk: + iounmap(pl022->virtbase); + err_no_ioremap: + amba_release_regions(adev); + err_no_ioregion: + spi_master_put(master); + err_no_master: + err_no_pdata: + return status; +} + +static int __exit +pl022_remove(struct amba_device *adev) +{ + struct pl022 *pl022 = amba_get_drvdata(adev); + int status = 0; + if (!pl022) + return 0; + + /* Remove the queue */ + status = destroy_queue(pl022); + if (status != 0) { + dev_err(&adev->dev, + "queue remove failed (%d)\n", status); + return status; + } + load_ssp_default_config(pl022); + free_irq(adev->irq[0], pl022); + clk_disable(pl022->clk); + clk_put(pl022->clk); + iounmap(pl022->virtbase); + amba_release_regions(adev); + tasklet_disable(&pl022->pump_transfers); + spi_unregister_master(pl022->master); + spi_master_put(pl022->master); + amba_set_drvdata(adev, NULL); + dev_dbg(&adev->dev, "remove succeded\n"); + return 0; +} + +#ifdef CONFIG_PM +static int pl022_suspend(struct amba_device *adev, pm_message_t state) +{ + struct pl022 *pl022 = amba_get_drvdata(adev); + int status = 0; + + status = stop_queue(pl022); + if (status) { + dev_warn(&adev->dev, "suspend cannot stop queue\n"); + return status; + } + + clk_enable(pl022->clk); + load_ssp_default_config(pl022); + clk_disable(pl022->clk); + dev_dbg(&adev->dev, "suspended\n"); + return 0; +} + +static int pl022_resume(struct amba_device *adev) +{ + struct pl022 *pl022 = amba_get_drvdata(adev); + int status = 0; + + /* Start the queue running */ + status = start_queue(pl022); + if (status) + dev_err(&adev->dev, "problem starting queue (%d)\n", status); + else + dev_dbg(&adev->dev, "resumed\n"); + + return status; +} +#else +#define pl022_suspend NULL +#define pl022_resume NULL +#endif /* CONFIG_PM */ + +static struct vendor_data vendor_arm = { + .fifodepth = 8, + .max_bpw = 16, + .unidir = false, +}; + + +static struct vendor_data vendor_st = { + .fifodepth = 32, + .max_bpw = 32, + .unidir = false, +}; + +static struct amba_id pl022_ids[] = { + { + /* + * ARM PL022 variant, this has a 16bit wide + * and 8 locations deep TX/RX FIFO + */ + .id = 0x00041022, + .mask = 0x000fffff, + .data = &vendor_arm, + }, + { + /* + * ST Micro derivative, this has 32bit wide + * and 32 locations deep TX/RX FIFO + */ + .id = 0x00108022, + .mask = 0xffffffff, + .data = &vendor_st, + }, + { 0, 0 }, +}; + +static struct amba_driver pl022_driver = { + .drv = { + .name = "ssp-pl022", + }, + .id_table = pl022_ids, + .probe = pl022_probe, + .remove = __exit_p(pl022_remove), + .suspend = pl022_suspend, + .resume = pl022_resume, +}; + + +static int __init pl022_init(void) +{ + return amba_driver_register(&pl022_driver); +} + +module_init(pl022_init); + +static void __exit pl022_exit(void) +{ + amba_driver_unregister(&pl022_driver); +} + +module_exit(pl022_exit); + +MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); +MODULE_DESCRIPTION("PL022 SSP Controller Driver"); +MODULE_LICENSE("GPL"); |
