diff options
Diffstat (limited to 'drivers/spi/xilinx_spi.c')
| -rw-r--r-- | drivers/spi/xilinx_spi.c | 355 |
1 files changed, 171 insertions, 184 deletions
diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c index 5a143b9..9f38637 100644 --- a/drivers/spi/xilinx_spi.c +++ b/drivers/spi/xilinx_spi.c @@ -14,22 +14,20 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/interrupt.h> -#include <linux/platform_device.h> - -#include <linux/of_platform.h> -#include <linux/of_device.h> -#include <linux/of_spi.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> #include <linux/io.h> +#include "xilinx_spi.h" +#include <linux/spi/xilinx_spi.h> + #define XILINX_SPI_NAME "xilinx_spi" /* Register definitions as per "OPB Serial Peripheral Interface (SPI) (v1.00e) * Product Specification", DS464 */ -#define XSPI_CR_OFFSET 0x62 /* 16-bit Control Register */ +#define XSPI_CR_OFFSET 0x60 /* Control Register */ #define XSPI_CR_ENABLE 0x02 #define XSPI_CR_MASTER_MODE 0x04 @@ -40,8 +38,9 @@ #define XSPI_CR_RXFIFO_RESET 0x40 #define XSPI_CR_MANUAL_SSELECT 0x80 #define XSPI_CR_TRANS_INHIBIT 0x100 +#define XSPI_CR_LSB_FIRST 0x200 -#define XSPI_SR_OFFSET 0x67 /* 8-bit Status Register */ +#define XSPI_SR_OFFSET 0x64 /* Status Register */ #define XSPI_SR_RX_EMPTY_MASK 0x01 /* Receive FIFO is empty */ #define XSPI_SR_RX_FULL_MASK 0x02 /* Receive FIFO is full */ @@ -49,8 +48,8 @@ #define XSPI_SR_TX_FULL_MASK 0x08 /* Transmit FIFO is full */ #define XSPI_SR_MODE_FAULT_MASK 0x10 /* Mode fault error */ -#define XSPI_TXD_OFFSET 0x6b /* 8-bit Data Transmit Register */ -#define XSPI_RXD_OFFSET 0x6f /* 8-bit Data Receive Register */ +#define XSPI_TXD_OFFSET 0x68 /* Data Transmit Register */ +#define XSPI_RXD_OFFSET 0x6c /* Data Receive Register */ #define XSPI_SSR_OFFSET 0x70 /* 32-bit Slave Select Register */ @@ -70,6 +69,7 @@ #define XSPI_INTR_TX_UNDERRUN 0x08 /* TxFIFO was underrun */ #define XSPI_INTR_RX_FULL 0x10 /* RxFIFO is full */ #define XSPI_INTR_RX_OVERRUN 0x20 /* RxFIFO was overrun */ +#define XSPI_INTR_TX_HALF_EMPTY 0x40 /* TxFIFO is half empty */ #define XIPIF_V123B_RESETR_OFFSET 0x40 /* IPIF reset register */ #define XIPIF_V123B_RESET_MASK 0x0a /* the value to write */ @@ -78,35 +78,85 @@ struct xilinx_spi { /* bitbang has to be first */ struct spi_bitbang bitbang; struct completion done; - + struct resource mem; /* phys mem */ void __iomem *regs; /* virt. address of the control registers */ u32 irq; - u32 speed_hz; /* SCK has a fixed frequency of speed_hz Hz */ - u8 *rx_ptr; /* pointer in the Tx buffer */ const u8 *tx_ptr; /* pointer in the Rx buffer */ int remaining_bytes; /* the number of bytes left to transfer */ + u8 bits_per_word; + unsigned int (*read_fn) (void __iomem *); + void (*write_fn) (u32, void __iomem *); + void (*tx_fn) (struct xilinx_spi *); + void (*rx_fn) (struct xilinx_spi *); }; -static void xspi_init_hw(void __iomem *regs_base) +static void xspi_tx8(struct xilinx_spi *xspi) +{ + xspi->write_fn(*xspi->tx_ptr, xspi->regs + XSPI_TXD_OFFSET); + xspi->tx_ptr++; +} + +static void xspi_tx16(struct xilinx_spi *xspi) +{ + xspi->write_fn(*(u16 *)(xspi->tx_ptr), xspi->regs + XSPI_TXD_OFFSET); + xspi->tx_ptr += 2; +} + +static void xspi_tx32(struct xilinx_spi *xspi) +{ + xspi->write_fn(*(u32 *)(xspi->tx_ptr), xspi->regs + XSPI_TXD_OFFSET); + xspi->tx_ptr += 4; +} + +static void xspi_rx8(struct xilinx_spi *xspi) +{ + u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET); + if (xspi->rx_ptr) { + *xspi->rx_ptr = data & 0xff; + xspi->rx_ptr++; + } +} + +static void xspi_rx16(struct xilinx_spi *xspi) { + u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET); + if (xspi->rx_ptr) { + *(u16 *)(xspi->rx_ptr) = data & 0xffff; + xspi->rx_ptr += 2; + } +} + +static void xspi_rx32(struct xilinx_spi *xspi) +{ + u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET); + if (xspi->rx_ptr) { + *(u32 *)(xspi->rx_ptr) = data; + xspi->rx_ptr += 4; + } +} + +static void xspi_init_hw(struct xilinx_spi *xspi) +{ + void __iomem *regs_base = xspi->regs; + /* Reset the SPI device */ - out_be32(regs_base + XIPIF_V123B_RESETR_OFFSET, - XIPIF_V123B_RESET_MASK); + xspi->write_fn(XIPIF_V123B_RESET_MASK, + regs_base + XIPIF_V123B_RESETR_OFFSET); /* Disable all the interrupts just in case */ - out_be32(regs_base + XIPIF_V123B_IIER_OFFSET, 0); + xspi->write_fn(0, regs_base + XIPIF_V123B_IIER_OFFSET); /* Enable the global IPIF interrupt */ - out_be32(regs_base + XIPIF_V123B_DGIER_OFFSET, - XIPIF_V123B_GINTR_ENABLE); + xspi->write_fn(XIPIF_V123B_GINTR_ENABLE, + regs_base + XIPIF_V123B_DGIER_OFFSET); /* Deselect the slave on the SPI bus */ - out_be32(regs_base + XSPI_SSR_OFFSET, 0xffff); + xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET); /* Disable the transmitter, enable Manual Slave Select Assertion, * put SPI controller into master mode, and enable it */ - out_be16(regs_base + XSPI_CR_OFFSET, - XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT - | XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE); + xspi->write_fn(XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT | + XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET | + XSPI_CR_RXFIFO_RESET, regs_base + XSPI_CR_OFFSET); } static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) @@ -115,16 +165,16 @@ static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) if (is_on == BITBANG_CS_INACTIVE) { /* Deselect the slave on the SPI bus */ - out_be32(xspi->regs + XSPI_SSR_OFFSET, 0xffff); + xspi->write_fn(0xffff, xspi->regs + XSPI_SSR_OFFSET); } else if (is_on == BITBANG_CS_ACTIVE) { /* Set the SPI clock phase and polarity */ - u16 cr = in_be16(xspi->regs + XSPI_CR_OFFSET) + u16 cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) & ~XSPI_CR_MODE_MASK; if (spi->mode & SPI_CPHA) cr |= XSPI_CR_CPHA; if (spi->mode & SPI_CPOL) cr |= XSPI_CR_CPOL; - out_be16(xspi->regs + XSPI_CR_OFFSET, cr); + xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); /* We do not check spi->max_speed_hz here as the SPI clock * frequency is not software programmable (the IP block design @@ -132,25 +182,27 @@ static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) */ /* Activate the chip select */ - out_be32(xspi->regs + XSPI_SSR_OFFSET, - ~(0x0001 << spi->chip_select)); + xspi->write_fn(~(0x0001 << spi->chip_select), + xspi->regs + XSPI_SSR_OFFSET); } } /* spi_bitbang requires custom setup_transfer() to be defined if there is a * custom txrx_bufs(). We have nothing to setup here as the SPI IP block - * supports just 8 bits per word, and SPI clock can't be changed in software. - * Check for 8 bits per word. Chip select delay calculations could be + * supports 8 or 16 bits per word which cannot be changed in software. + * SPI clock can't be changed in software either. + * Check for correct bits per word. Chip select delay calculations could be * added here as soon as bitbang_work() can be made aware of the delay value. */ static int xilinx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { + struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); u8 bits_per_word; bits_per_word = (t && t->bits_per_word) ? t->bits_per_word : spi->bits_per_word; - if (bits_per_word != 8) { + if (bits_per_word != xspi->bits_per_word) { dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n", __func__, bits_per_word); return -EINVAL; @@ -161,17 +213,16 @@ static int xilinx_spi_setup_transfer(struct spi_device *spi, static int xilinx_spi_setup(struct spi_device *spi) { - struct spi_bitbang *bitbang; - struct xilinx_spi *xspi; - int retval; - - xspi = spi_master_get_devdata(spi->master); - bitbang = &xspi->bitbang; - - retval = xilinx_spi_setup_transfer(spi, NULL); - if (retval < 0) - return retval; - + /* always return 0, we can not check the number of bits. + * There are cases when SPI setup is called before any driver is + * there, in that case the SPI core defaults to 8 bits, which we + * do not support in some cases. But if we return an error, the + * SPI device would not be registered and no driver can get hold of it + * When the driver is there, it will call SPI setup again with the + * correct number of bits per transfer. + * If a driver setups with the wrong bit number, it will fail when + * it tries to do a transfer + */ return 0; } @@ -180,15 +231,14 @@ static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi) u8 sr; /* Fill the Tx FIFO with as many bytes as possible */ - sr = in_8(xspi->regs + XSPI_SR_OFFSET); + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); while ((sr & XSPI_SR_TX_FULL_MASK) == 0 && xspi->remaining_bytes > 0) { - if (xspi->tx_ptr) { - out_8(xspi->regs + XSPI_TXD_OFFSET, *xspi->tx_ptr++); - } else { - out_8(xspi->regs + XSPI_TXD_OFFSET, 0); - } - xspi->remaining_bytes--; - sr = in_8(xspi->regs + XSPI_SR_OFFSET); + if (xspi->tx_ptr) + xspi->tx_fn(xspi); + else + xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET); + xspi->remaining_bytes -= xspi->bits_per_word / 8; + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); } } @@ -210,18 +260,19 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) /* Enable the transmit empty interrupt, which we use to determine * progress on the transmission. */ - ipif_ier = in_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET); - out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET, - ipif_ier | XSPI_INTR_TX_EMPTY); + ipif_ier = xspi->read_fn(xspi->regs + XIPIF_V123B_IIER_OFFSET); + xspi->write_fn(ipif_ier | XSPI_INTR_TX_EMPTY, + xspi->regs + XIPIF_V123B_IIER_OFFSET); /* Start the transfer by not inhibiting the transmitter any longer */ - cr = in_be16(xspi->regs + XSPI_CR_OFFSET) & ~XSPI_CR_TRANS_INHIBIT; - out_be16(xspi->regs + XSPI_CR_OFFSET, cr); + cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) & + ~XSPI_CR_TRANS_INHIBIT; + xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); wait_for_completion(&xspi->done); /* Disable the transmit empty interrupt */ - out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET, ipif_ier); + xspi->write_fn(ipif_ier, xspi->regs + XIPIF_V123B_IIER_OFFSET); return t->len - xspi->remaining_bytes; } @@ -238,8 +289,8 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id) u32 ipif_isr; /* Get the IPIF interrupts, and clear them immediately */ - ipif_isr = in_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET); - out_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET, ipif_isr); + ipif_isr = xspi->read_fn(xspi->regs + XIPIF_V123B_IISR_OFFSET); + xspi->write_fn(ipif_isr, xspi->regs + XIPIF_V123B_IISR_OFFSET); if (ipif_isr & XSPI_INTR_TX_EMPTY) { /* Transmission completed */ u16 cr; @@ -250,20 +301,15 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id) * transmitter while the Isr refills the transmit register/FIFO, * or make sure it is stopped if we're done. */ - cr = in_be16(xspi->regs + XSPI_CR_OFFSET); - out_be16(xspi->regs + XSPI_CR_OFFSET, - cr | XSPI_CR_TRANS_INHIBIT); + cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET); + xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT, + xspi->regs + XSPI_CR_OFFSET); /* Read out all the data from the Rx FIFO */ - sr = in_8(xspi->regs + XSPI_SR_OFFSET); + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) { - u8 data; - - data = in_8(xspi->regs + XSPI_RXD_OFFSET); - if (xspi->rx_ptr) { - *xspi->rx_ptr++ = data; - } - sr = in_8(xspi->regs + XSPI_SR_OFFSET); + xspi->rx_fn(xspi); + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); } /* See if there is more data to send */ @@ -272,7 +318,7 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id) /* Start the transfer by not inhibiting the * transmitter any longer */ - out_be16(xspi->regs + XSPI_CR_OFFSET, cr); + xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); } else { /* No more data to send. * Indicate the transfer is completed. @@ -284,40 +330,22 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id) return IRQ_HANDLED; } -static int __init xilinx_spi_of_probe(struct of_device *ofdev, - const struct of_device_id *match) +struct spi_master *xilinx_spi_init(struct device *dev, struct resource *mem, + u32 irq, s16 bus_num) { struct spi_master *master; struct xilinx_spi *xspi; - struct resource r_irq_struct; - struct resource r_mem_struct; - - struct resource *r_irq = &r_irq_struct; - struct resource *r_mem = &r_mem_struct; - int rc = 0; - const u32 *prop; - int len; - - /* Get resources(memory, IRQ) associated with the device */ - master = spi_alloc_master(&ofdev->dev, sizeof(struct xilinx_spi)); + struct xspi_platform_data *pdata = dev->platform_data; + int ret; - if (master == NULL) { - return -ENOMEM; + if (!pdata) { + dev_err(dev, "No platform data attached\n"); + return NULL; } - dev_set_drvdata(&ofdev->dev, master); - - rc = of_address_to_resource(ofdev->node, 0, r_mem); - if (rc) { - dev_warn(&ofdev->dev, "invalid address\n"); - goto put_master; - } - - rc = of_irq_to_resource(ofdev->node, 0, r_irq); - if (rc == NO_IRQ) { - dev_warn(&ofdev->dev, "no IRQ found\n"); - goto put_master; - } + master = spi_alloc_master(dev, sizeof(struct xilinx_spi)); + if (!master) + return NULL; /* the spi->mode bits understood by this driver: */ master->mode_bits = SPI_CPOL | SPI_CPHA; @@ -330,128 +358,87 @@ static int __init xilinx_spi_of_probe(struct of_device *ofdev, xspi->bitbang.master->setup = xilinx_spi_setup; init_completion(&xspi->done); - xspi->irq = r_irq->start; - - if (!request_mem_region(r_mem->start, - r_mem->end - r_mem->start + 1, XILINX_SPI_NAME)) { - rc = -ENXIO; - dev_warn(&ofdev->dev, "memory request failure\n"); + if (!request_mem_region(mem->start, resource_size(mem), + XILINX_SPI_NAME)) goto put_master; - } - xspi->regs = ioremap(r_mem->start, r_mem->end - r_mem->start + 1); + xspi->regs = ioremap(mem->start, resource_size(mem)); if (xspi->regs == NULL) { - rc = -ENOMEM; - dev_warn(&ofdev->dev, "ioremap failure\n"); - goto release_mem; + dev_warn(dev, "ioremap failure\n"); + goto map_failed; } - xspi->irq = r_irq->start; - - /* dynamic bus assignment */ - master->bus_num = -1; - /* number of slave select bits is required */ - prop = of_get_property(ofdev->node, "xlnx,num-ss-bits", &len); - if (!prop || len < sizeof(*prop)) { - dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n"); - goto unmap_io; + master->bus_num = bus_num; + master->num_chipselect = pdata->num_chipselect; + + xspi->mem = *mem; + xspi->irq = irq; + if (pdata->little_endian) { + xspi->read_fn = ioread32; + xspi->write_fn = iowrite32; + } else { + xspi->read_fn = ioread32be; + xspi->write_fn = iowrite32be; } - master->num_chipselect = *prop; + xspi->bits_per_word = pdata->bits_per_word; + if (xspi->bits_per_word == 8) { + xspi->tx_fn = xspi_tx8; + xspi->rx_fn = xspi_rx8; + } else if (xspi->bits_per_word == 16) { + xspi->tx_fn = xspi_tx16; + xspi->rx_fn = xspi_rx16; + } else if (xspi->bits_per_word == 32) { + xspi->tx_fn = xspi_tx32; + xspi->rx_fn = xspi_rx32; + } else + goto unmap_io; + /* SPI controller initializations */ - xspi_init_hw(xspi->regs); + xspi_init_hw(xspi); /* Register for SPI Interrupt */ - rc = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi); - if (rc != 0) { - dev_warn(&ofdev->dev, "irq request failure: %d\n", xspi->irq); + ret = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi); + if (ret) goto unmap_io; - } - rc = spi_bitbang_start(&xspi->bitbang); - if (rc != 0) { - dev_err(&ofdev->dev, "spi_bitbang_start FAILED\n"); + ret = spi_bitbang_start(&xspi->bitbang); + if (ret) { + dev_err(dev, "spi_bitbang_start FAILED\n"); goto free_irq; } - dev_info(&ofdev->dev, "at 0x%08X mapped to 0x%08X, irq=%d\n", - (unsigned int)r_mem->start, (u32)xspi->regs, xspi->irq); - - /* Add any subnodes on the SPI bus */ - of_register_spi_devices(master, ofdev->node); - - return rc; + dev_info(dev, "at 0x%08llX mapped to 0x%p, irq=%d\n", + (unsigned long long)mem->start, xspi->regs, xspi->irq); + return master; free_irq: free_irq(xspi->irq, xspi); unmap_io: iounmap(xspi->regs); -release_mem: - release_mem_region(r_mem->start, resource_size(r_mem)); +map_failed: + release_mem_region(mem->start, resource_size(mem)); put_master: spi_master_put(master); - return rc; + return NULL; } +EXPORT_SYMBOL(xilinx_spi_init); -static int __devexit xilinx_spi_remove(struct of_device *ofdev) +void xilinx_spi_deinit(struct spi_master *master) { struct xilinx_spi *xspi; - struct spi_master *master; - struct resource r_mem; - master = platform_get_drvdata(ofdev); xspi = spi_master_get_devdata(master); spi_bitbang_stop(&xspi->bitbang); free_irq(xspi->irq, xspi); iounmap(xspi->regs); - if (!of_address_to_resource(ofdev->node, 0, &r_mem)) - release_mem_region(r_mem.start, resource_size(&r_mem)); - dev_set_drvdata(&ofdev->dev, 0); - spi_master_put(xspi->bitbang.master); - - return 0; -} - -/* work with hotplug and coldplug */ -MODULE_ALIAS("platform:" XILINX_SPI_NAME); - -static int __exit xilinx_spi_of_remove(struct of_device *op) -{ - return xilinx_spi_remove(op); -} -static struct of_device_id xilinx_spi_of_match[] = { - { .compatible = "xlnx,xps-spi-2.00.a", }, - { .compatible = "xlnx,xps-spi-2.00.b", }, - {} -}; - -MODULE_DEVICE_TABLE(of, xilinx_spi_of_match); - -static struct of_platform_driver xilinx_spi_of_driver = { - .owner = THIS_MODULE, - .name = "xilinx-xps-spi", - .match_table = xilinx_spi_of_match, - .probe = xilinx_spi_of_probe, - .remove = __exit_p(xilinx_spi_of_remove), - .driver = { - .name = "xilinx-xps-spi", - .owner = THIS_MODULE, - }, -}; - -static int __init xilinx_spi_init(void) -{ - return of_register_platform_driver(&xilinx_spi_of_driver); + release_mem_region(xspi->mem.start, resource_size(&xspi->mem)); + spi_master_put(xspi->bitbang.master); } -module_init(xilinx_spi_init); +EXPORT_SYMBOL(xilinx_spi_deinit); -static void __exit xilinx_spi_exit(void) -{ - of_unregister_platform_driver(&xilinx_spi_of_driver); -} -module_exit(xilinx_spi_exit); MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>"); MODULE_DESCRIPTION("Xilinx SPI driver"); MODULE_LICENSE("GPL"); |
