diff options
Diffstat (limited to 'drivers/tty/serial/mfd.c')
| -rw-r--r-- | drivers/tty/serial/mfd.c | 1513 |
1 files changed, 1513 insertions, 0 deletions
diff --git a/drivers/tty/serial/mfd.c b/drivers/tty/serial/mfd.c new file mode 100644 index 0000000..d40010a --- /dev/null +++ b/drivers/tty/serial/mfd.c @@ -0,0 +1,1513 @@ +/* + * mfd.c: driver for High Speed UART device of Intel Medfield platform + * + * Refer pxa.c, 8250.c and some other drivers in drivers/serial/ + * + * (C) Copyright 2010 Intel Corporation + * + * 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; version 2 + * of the License. + */ + +/* Notes: + * 1. DMA channel allocation: 0/1 channel are assigned to port 0, + * 2/3 chan to port 1, 4/5 chan to port 3. Even number chans + * are used for RX, odd chans for TX + * + * 2. In A0 stepping, UART will not support TX half empty flag + * + * 3. The RI/DSR/DCD/DTR are not pinned out, DCD & DSR are always + * asserted, only when the HW is reset the DDCD and DDSR will + * be triggered + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/sysrq.h> +#include <linux/slab.h> +#include <linux/serial_reg.h> +#include <linux/circ_buf.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial_core.h> +#include <linux/serial_mfd.h> +#include <linux/dma-mapping.h> +#include <linux/pci.h> +#include <linux/io.h> +#include <linux/debugfs.h> + +#define MFD_HSU_A0_STEPPING 1 + +#define HSU_DMA_BUF_SIZE 2048 + +#define chan_readl(chan, offset) readl(chan->reg + offset) +#define chan_writel(chan, offset, val) writel(val, chan->reg + offset) + +#define mfd_readl(obj, offset) readl(obj->reg + offset) +#define mfd_writel(obj, offset, val) writel(val, obj->reg + offset) + +#define HSU_DMA_TIMEOUT_CHECK_FREQ (HZ/10) + +struct hsu_dma_buffer { + u8 *buf; + dma_addr_t dma_addr; + u32 dma_size; + u32 ofs; +}; + +struct hsu_dma_chan { + u32 id; + enum dma_data_direction dirt; + struct uart_hsu_port *uport; + void __iomem *reg; + struct timer_list rx_timer; /* only needed by RX channel */ +}; + +struct uart_hsu_port { + struct uart_port port; + unsigned char ier; + unsigned char lcr; + unsigned char mcr; + unsigned int lsr_break_flag; + char name[12]; + int index; + struct device *dev; + + struct hsu_dma_chan *txc; + struct hsu_dma_chan *rxc; + struct hsu_dma_buffer txbuf; + struct hsu_dma_buffer rxbuf; + int use_dma; /* flag for DMA/PIO */ + int running; + int dma_tx_on; +}; + +/* Top level data structure of HSU */ +struct hsu_port { + void __iomem *reg; + unsigned long paddr; + unsigned long iolen; + u32 irq; + + struct uart_hsu_port port[3]; + struct hsu_dma_chan chans[10]; + + struct dentry *debugfs; +}; + +static inline unsigned int serial_in(struct uart_hsu_port *up, int offset) +{ + unsigned int val; + + if (offset > UART_MSR) { + offset <<= 2; + val = readl(up->port.membase + offset); + } else + val = (unsigned int)readb(up->port.membase + offset); + + return val; +} + +static inline void serial_out(struct uart_hsu_port *up, int offset, int value) +{ + if (offset > UART_MSR) { + offset <<= 2; + writel(value, up->port.membase + offset); + } else { + unsigned char val = value & 0xff; + writeb(val, up->port.membase + offset); + } +} + +#ifdef CONFIG_DEBUG_FS + +#define HSU_REGS_BUFSIZE 1024 + +static int hsu_show_regs_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return 0; +} + +static ssize_t port_show_regs(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct uart_hsu_port *up = file->private_data; + char *buf; + u32 len = 0; + ssize_t ret; + + buf = kzalloc(HSU_REGS_BUFSIZE, GFP_KERNEL); + if (!buf) + return 0; + + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "MFD HSU port[%d] regs:\n", up->index); + + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "=================================\n"); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "IER: \t\t0x%08x\n", serial_in(up, UART_IER)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "IIR: \t\t0x%08x\n", serial_in(up, UART_IIR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "LCR: \t\t0x%08x\n", serial_in(up, UART_LCR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "MCR: \t\t0x%08x\n", serial_in(up, UART_MCR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "LSR: \t\t0x%08x\n", serial_in(up, UART_LSR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "MSR: \t\t0x%08x\n", serial_in(up, UART_MSR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "FOR: \t\t0x%08x\n", serial_in(up, UART_FOR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "PS: \t\t0x%08x\n", serial_in(up, UART_PS)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "MUL: \t\t0x%08x\n", serial_in(up, UART_MUL)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "DIV: \t\t0x%08x\n", serial_in(up, UART_DIV)); + + if (len > HSU_REGS_BUFSIZE) + len = HSU_REGS_BUFSIZE; + + ret = simple_read_from_buffer(user_buf, count, ppos, buf, len); + kfree(buf); + return ret; +} + +static ssize_t dma_show_regs(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct hsu_dma_chan *chan = file->private_data; + char *buf; + u32 len = 0; + ssize_t ret; + + buf = kzalloc(HSU_REGS_BUFSIZE, GFP_KERNEL); + if (!buf) + return 0; + + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "MFD HSU DMA channel [%d] regs:\n", chan->id); + + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "=================================\n"); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "CR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_CR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "DCR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_DCR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "BSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_BSR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "MOTSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_MOTSR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D0SAR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D0TSR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D1SAR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D1TSR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D2SAR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D2TSR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3SAR)); + len += snprintf(buf + len, HSU_REGS_BUFSIZE - len, + "D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3TSR)); + + if (len > HSU_REGS_BUFSIZE) + len = HSU_REGS_BUFSIZE; + + ret = simple_read_from_buffer(user_buf, count, ppos, buf, len); + kfree(buf); + return ret; +} + +static const struct file_operations port_regs_ops = { + .owner = THIS_MODULE, + .open = hsu_show_regs_open, + .read = port_show_regs, + .llseek = default_llseek, +}; + +static const struct file_operations dma_regs_ops = { + .owner = THIS_MODULE, + .open = hsu_show_regs_open, + .read = dma_show_regs, + .llseek = default_llseek, +}; + +static int hsu_debugfs_init(struct hsu_port *hsu) +{ + int i; + char name[32]; + + hsu->debugfs = debugfs_create_dir("hsu", NULL); + if (!hsu->debugfs) + return -ENOMEM; + + for (i = 0; i < 3; i++) { + snprintf(name, sizeof(name), "port_%d_regs", i); + debugfs_create_file(name, S_IFREG | S_IRUGO, + hsu->debugfs, (void *)(&hsu->port[i]), &port_regs_ops); + } + + for (i = 0; i < 6; i++) { + snprintf(name, sizeof(name), "dma_chan_%d_regs", i); + debugfs_create_file(name, S_IFREG | S_IRUGO, + hsu->debugfs, (void *)&hsu->chans[i], &dma_regs_ops); + } + + return 0; +} + +static void hsu_debugfs_remove(struct hsu_port *hsu) +{ + if (hsu->debugfs) + debugfs_remove_recursive(hsu->debugfs); +} + +#else +static inline int hsu_debugfs_init(struct hsu_port *hsu) +{ + return 0; +} + +static inline void hsu_debugfs_remove(struct hsu_port *hsu) +{ +} +#endif /* CONFIG_DEBUG_FS */ + +static void serial_hsu_enable_ms(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + + up->ier |= UART_IER_MSI; + serial_out(up, UART_IER, up->ier); +} + +void hsu_dma_tx(struct uart_hsu_port *up) +{ + struct circ_buf *xmit = &up->port.state->xmit; + struct hsu_dma_buffer *dbuf = &up->txbuf; + int count; + + /* test_and_set_bit may be better, but anyway it's in lock protected mode */ + if (up->dma_tx_on) + return; + + /* Update the circ buf info */ + xmit->tail += dbuf->ofs; + xmit->tail &= UART_XMIT_SIZE - 1; + + up->port.icount.tx += dbuf->ofs; + dbuf->ofs = 0; + + /* Disable the channel */ + chan_writel(up->txc, HSU_CH_CR, 0x0); + + if (!uart_circ_empty(xmit) && !uart_tx_stopped(&up->port)) { + dma_sync_single_for_device(up->port.dev, + dbuf->dma_addr, + dbuf->dma_size, + DMA_TO_DEVICE); + + count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + dbuf->ofs = count; + + /* Reprogram the channel */ + chan_writel(up->txc, HSU_CH_D0SAR, dbuf->dma_addr + xmit->tail); + chan_writel(up->txc, HSU_CH_D0TSR, count); + + /* Reenable the channel */ + chan_writel(up->txc, HSU_CH_DCR, 0x1 + | (0x1 << 8) + | (0x1 << 16) + | (0x1 << 24)); + up->dma_tx_on = 1; + chan_writel(up->txc, HSU_CH_CR, 0x1); + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&up->port); +} + +/* The buffer is already cache coherent */ +void hsu_dma_start_rx_chan(struct hsu_dma_chan *rxc, struct hsu_dma_buffer *dbuf) +{ + dbuf->ofs = 0; + + chan_writel(rxc, HSU_CH_BSR, 32); + chan_writel(rxc, HSU_CH_MOTSR, 4); + + chan_writel(rxc, HSU_CH_D0SAR, dbuf->dma_addr); + chan_writel(rxc, HSU_CH_D0TSR, dbuf->dma_size); + chan_writel(rxc, HSU_CH_DCR, 0x1 | (0x1 << 8) + | (0x1 << 16) + | (0x1 << 24) /* timeout bit, see HSU Errata 1 */ + ); + chan_writel(rxc, HSU_CH_CR, 0x3); + + mod_timer(&rxc->rx_timer, jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ); +} + +/* Protected by spin_lock_irqsave(port->lock) */ +static void serial_hsu_start_tx(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + + if (up->use_dma) { + hsu_dma_tx(up); + } else if (!(up->ier & UART_IER_THRI)) { + up->ier |= UART_IER_THRI; + serial_out(up, UART_IER, up->ier); + } +} + +static void serial_hsu_stop_tx(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + struct hsu_dma_chan *txc = up->txc; + + if (up->use_dma) + chan_writel(txc, HSU_CH_CR, 0x0); + else if (up->ier & UART_IER_THRI) { + up->ier &= ~UART_IER_THRI; + serial_out(up, UART_IER, up->ier); + } +} + +/* This is always called in spinlock protected mode, so + * modify timeout timer is safe here */ +void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts) +{ + struct hsu_dma_buffer *dbuf = &up->rxbuf; + struct hsu_dma_chan *chan = up->rxc; + struct uart_port *port = &up->port; + struct tty_struct *tty = port->state->port.tty; + int count; + + if (!tty) + return; + + /* + * First need to know how many is already transferred, + * then check if its a timeout DMA irq, and return + * the trail bytes out, push them up and reenable the + * channel + */ + + /* Timeout IRQ, need wait some time, see Errata 2 */ + if (int_sts & 0xf00) + udelay(2); + + /* Stop the channel */ + chan_writel(chan, HSU_CH_CR, 0x0); + + count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr; + if (!count) { + /* Restart the channel before we leave */ + chan_writel(chan, HSU_CH_CR, 0x3); + return; + } + del_timer(&chan->rx_timer); + + dma_sync_single_for_cpu(port->dev, dbuf->dma_addr, + dbuf->dma_size, DMA_FROM_DEVICE); + + /* + * Head will only wrap around when we recycle + * the DMA buffer, and when that happens, we + * explicitly set tail to 0. So head will + * always be greater than tail. + */ + tty_insert_flip_string(tty, dbuf->buf, count); + port->icount.rx += count; + + dma_sync_single_for_device(up->port.dev, dbuf->dma_addr, + dbuf->dma_size, DMA_FROM_DEVICE); + + /* Reprogram the channel */ + chan_writel(chan, HSU_CH_D0SAR, dbuf->dma_addr); + chan_writel(chan, HSU_CH_D0TSR, dbuf->dma_size); + chan_writel(chan, HSU_CH_DCR, 0x1 + | (0x1 << 8) + | (0x1 << 16) + | (0x1 << 24) /* timeout bit, see HSU Errata 1 */ + ); + tty_flip_buffer_push(tty); + + chan_writel(chan, HSU_CH_CR, 0x3); + chan->rx_timer.expires = jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ; + add_timer(&chan->rx_timer); + +} + +static void serial_hsu_stop_rx(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + struct hsu_dma_chan *chan = up->rxc; + + if (up->use_dma) + chan_writel(chan, HSU_CH_CR, 0x2); + else { + up->ier &= ~UART_IER_RLSI; + up->port.read_status_mask &= ~UART_LSR_DR; + serial_out(up, UART_IER, up->ier); + } +} + +static inline void receive_chars(struct uart_hsu_port *up, int *status) +{ + struct tty_struct *tty = up->port.state->port.tty; + unsigned int ch, flag; + unsigned int max_count = 256; + + if (!tty) + return; + + do { + ch = serial_in(up, UART_RX); + flag = TTY_NORMAL; + up->port.icount.rx++; + + if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE | + UART_LSR_FE | UART_LSR_OE))) { + + dev_warn(up->dev, "We really rush into ERR/BI case" + "status = 0x%02x", *status); + /* For statistics only */ + if (*status & UART_LSR_BI) { + *status &= ~(UART_LSR_FE | UART_LSR_PE); + up->port.icount.brk++; + /* + * We do the SysRQ and SAK checking + * here because otherwise the break + * may get masked by ignore_status_mask + * or read_status_mask. + */ + if (uart_handle_break(&up->port)) + goto ignore_char; + } else if (*status & UART_LSR_PE) + up->port.icount.parity++; + else if (*status & UART_LSR_FE) + up->port.icount.frame++; + if (*status & UART_LSR_OE) + up->port.icount.overrun++; + + /* Mask off conditions which should be ignored. */ + *status &= up->port.read_status_mask; + +#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE + if (up->port.cons && + up->port.cons->index == up->port.line) { + /* Recover the break flag from console xmit */ + *status |= up->lsr_break_flag; + up->lsr_break_flag = 0; + } +#endif + if (*status & UART_LSR_BI) { + flag = TTY_BREAK; + } else if (*status & UART_LSR_PE) + flag = TTY_PARITY; + else if (*status & UART_LSR_FE) + flag = TTY_FRAME; + } + + if (uart_handle_sysrq_char(&up->port, ch)) + goto ignore_char; + + uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag); + ignore_char: + *status = serial_in(up, UART_LSR); + } while ((*status & UART_LSR_DR) && max_count--); + tty_flip_buffer_push(tty); +} + +static void transmit_chars(struct uart_hsu_port *up) +{ + struct circ_buf *xmit = &up->port.state->xmit; + int count; + + if (up->port.x_char) { + serial_out(up, UART_TX, up->port.x_char); + up->port.icount.tx++; + up->port.x_char = 0; + return; + } + if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { + serial_hsu_stop_tx(&up->port); + return; + } + +#ifndef MFD_HSU_A0_STEPPING + count = up->port.fifosize / 2; +#else + /* + * A0 only supports fully empty IRQ, and the first char written + * into it won't clear the EMPT bit, so we may need be cautious + * by useing a shorter buffer + */ + count = up->port.fifosize - 4; +#endif + do { + serial_out(up, UART_TX, xmit->buf[xmit->tail]); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + + up->port.icount.tx++; + if (uart_circ_empty(xmit)) + break; + } while (--count > 0); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&up->port); + + if (uart_circ_empty(xmit)) + serial_hsu_stop_tx(&up->port); +} + +static inline void check_modem_status(struct uart_hsu_port *up) +{ + int status; + + status = serial_in(up, UART_MSR); + + if ((status & UART_MSR_ANY_DELTA) == 0) + return; + + if (status & UART_MSR_TERI) + up->port.icount.rng++; + if (status & UART_MSR_DDSR) + up->port.icount.dsr++; + /* We may only get DDCD when HW init and reset */ + if (status & UART_MSR_DDCD) + uart_handle_dcd_change(&up->port, status & UART_MSR_DCD); + /* Will start/stop_tx accordingly */ + if (status & UART_MSR_DCTS) + uart_handle_cts_change(&up->port, status & UART_MSR_CTS); + + wake_up_interruptible(&up->port.state->port.delta_msr_wait); +} + +/* + * This handles the interrupt from one port. + */ +static irqreturn_t port_irq(int irq, void *dev_id) +{ + struct uart_hsu_port *up = dev_id; + unsigned int iir, lsr; + unsigned long flags; + + if (unlikely(!up->running)) + return IRQ_NONE; + + spin_lock_irqsave(&up->port.lock, flags); + if (up->use_dma) { + lsr = serial_in(up, UART_LSR); + if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE | + UART_LSR_FE | UART_LSR_OE))) + dev_warn(up->dev, + "Got lsr irq while using DMA, lsr = 0x%2x\n", + lsr); + check_modem_status(up); + spin_unlock_irqrestore(&up->port.lock, flags); + return IRQ_HANDLED; + } + + iir = serial_in(up, UART_IIR); + if (iir & UART_IIR_NO_INT) { + spin_unlock_irqrestore(&up->port.lock, flags); + return IRQ_NONE; + } + + lsr = serial_in(up, UART_LSR); + if (lsr & UART_LSR_DR) + receive_chars(up, &lsr); + check_modem_status(up); + + /* lsr will be renewed during the receive_chars */ + if (lsr & UART_LSR_THRE) + transmit_chars(up); + + spin_unlock_irqrestore(&up->port.lock, flags); + return IRQ_HANDLED; +} + +static inline void dma_chan_irq(struct hsu_dma_chan *chan) +{ + struct uart_hsu_port *up = chan->uport; + unsigned long flags; + u32 int_sts; + + spin_lock_irqsave(&up->port.lock, flags); + + if (!up->use_dma || !up->running) + goto exit; + + /* + * No matter what situation, need read clear the IRQ status + * There is a bug, see Errata 5, HSD 2900918 + */ + int_sts = chan_readl(chan, HSU_CH_SR); + + /* Rx channel */ + if (chan->dirt == DMA_FROM_DEVICE) + hsu_dma_rx(up, int_sts); + + /* Tx channel */ + if (chan->dirt == DMA_TO_DEVICE) { + chan_writel(chan, HSU_CH_CR, 0x0); + up->dma_tx_on = 0; + hsu_dma_tx(up); + } + +exit: + spin_unlock_irqrestore(&up->port.lock, flags); + return; +} + +static irqreturn_t dma_irq(int irq, void *dev_id) +{ + struct hsu_port *hsu = dev_id; + u32 int_sts, i; + + int_sts = mfd_readl(hsu, HSU_GBL_DMAISR); + + /* Currently we only have 6 channels may be used */ + for (i = 0; i < 6; i++) { + if (int_sts & 0x1) + dma_chan_irq(&hsu->chans[i]); + int_sts >>= 1; + } + + return IRQ_HANDLED; +} + +static unsigned int serial_hsu_tx_empty(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + unsigned long flags; + unsigned int ret; + + spin_lock_irqsave(&up->port.lock, flags); + ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; + spin_unlock_irqrestore(&up->port.lock, flags); + + return ret; +} + +static unsigned int serial_hsu_get_mctrl(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + unsigned char status; + unsigned int ret; + + status = serial_in(up, UART_MSR); + + ret = 0; + if (status & UART_MSR_DCD) + ret |= TIOCM_CAR; + if (status & UART_MSR_RI) + ret |= TIOCM_RNG; + if (status & UART_MSR_DSR) + ret |= TIOCM_DSR; + if (status & UART_MSR_CTS) + ret |= TIOCM_CTS; + return ret; +} + +static void serial_hsu_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + unsigned char mcr = 0; + + if (mctrl & TIOCM_RTS) + mcr |= UART_MCR_RTS; + if (mctrl & TIOCM_DTR) + mcr |= UART_MCR_DTR; + if (mctrl & TIOCM_OUT1) + mcr |= UART_MCR_OUT1; + if (mctrl & TIOCM_OUT2) + mcr |= UART_MCR_OUT2; + if (mctrl & TIOCM_LOOP) + mcr |= UART_MCR_LOOP; + + mcr |= up->mcr; + + serial_out(up, UART_MCR, mcr); +} + +static void serial_hsu_break_ctl(struct uart_port *port, int break_state) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + unsigned long flags; + + spin_lock_irqsave(&up->port.lock, flags); + if (break_state == -1) + up->lcr |= UART_LCR_SBC; + else + up->lcr &= ~UART_LCR_SBC; + serial_out(up, UART_LCR, up->lcr); + spin_unlock_irqrestore(&up->port.lock, flags); +} + +/* + * What special to do: + * 1. chose the 64B fifo mode + * 2. make sure not to select half empty mode for A0 stepping + * 3. start dma or pio depends on configuration + * 4. we only allocate dma memory when needed + */ +static int serial_hsu_startup(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + unsigned long flags; + + /* + * Clear the FIFO buffers and disable them. + * (they will be reenabled in set_termios()) + */ + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | + UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); + serial_out(up, UART_FCR, 0); + + /* Clear the interrupt registers. */ + (void) serial_in(up, UART_LSR); + (void) serial_in(up, UART_RX); + (void) serial_in(up, UART_IIR); + (void) serial_in(up, UART_MSR); + + /* Now, initialize the UART, default is 8n1 */ + serial_out(up, UART_LCR, UART_LCR_WLEN8); + + spin_lock_irqsave(&up->port.lock, flags); + + up->port.mctrl |= TIOCM_OUT2; + serial_hsu_set_mctrl(&up->port, up->port.mctrl); + + /* + * Finally, enable interrupts. Note: Modem status interrupts + * are set via set_termios(), which will be occurring imminently + * anyway, so we don't enable them here. + */ + if (!up->use_dma) + up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE; + else + up->ier = 0; + serial_out(up, UART_IER, up->ier); + + spin_unlock_irqrestore(&up->port.lock, flags); + + /* DMA init */ + if (up->use_dma) { + struct hsu_dma_buffer *dbuf; + struct circ_buf *xmit = &port->state->xmit; + + up->dma_tx_on = 0; + + /* First allocate the RX buffer */ + dbuf = &up->rxbuf; + dbuf->buf = kzalloc(HSU_DMA_BUF_SIZE, GFP_KERNEL); + if (!dbuf->buf) { + up->use_dma = 0; + goto exit; + } + dbuf->dma_addr = dma_map_single(port->dev, + dbuf->buf, + HSU_DMA_BUF_SIZE, + DMA_FROM_DEVICE); + dbuf->dma_size = HSU_DMA_BUF_SIZE; + + /* Start the RX channel right now */ + hsu_dma_start_rx_chan(up->rxc, dbuf); + + /* Next init the TX DMA */ + dbuf = &up->txbuf; + dbuf->buf = xmit->buf; + dbuf->dma_addr = dma_map_single(port->dev, + dbuf->buf, + UART_XMIT_SIZE, + DMA_TO_DEVICE); + dbuf->dma_size = UART_XMIT_SIZE; + + /* This should not be changed all around */ + chan_writel(up->txc, HSU_CH_BSR, 32); + chan_writel(up->txc, HSU_CH_MOTSR, 4); + dbuf->ofs = 0; + } + +exit: + /* And clear the interrupt registers again for luck. */ + (void) serial_in(up, UART_LSR); + (void) serial_in(up, UART_RX); + (void) serial_in(up, UART_IIR); + (void) serial_in(up, UART_MSR); + + up->running = 1; + return 0; +} + +static void serial_hsu_shutdown(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + unsigned long flags; + + del_timer_sync(&up->rxc->rx_timer); + + /* Disable interrupts from this port */ + up->ier = 0; + serial_out(up, UART_IER, 0); + up->running = 0; + + spin_lock_irqsave(&up->port.lock, flags); + up->port.mctrl &= ~TIOCM_OUT2; + serial_hsu_set_mctrl(&up->port, up->port.mctrl); + spin_unlock_irqrestore(&up->port.lock, flags); + + /* Disable break condition and FIFOs */ + serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC); + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | + UART_FCR_CLEAR_RCVR | + UART_FCR_CLEAR_XMIT); + serial_out(up, UART_FCR, 0); +} + +static void +serial_hsu_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + struct tty_struct *tty = port->state->port.tty; + unsigned char cval, fcr = 0; + unsigned long flags; + unsigned int baud, quot; + u32 ps, mul; + + switch (termios->c_cflag & CSIZE) { + case CS5: + cval = UART_LCR_WLEN5; + break; + case CS6: + cval = UART_LCR_WLEN6; + break; + case CS7: + cval = UART_LCR_WLEN7; + break; + default: + case CS8: + cval = UART_LCR_WLEN8; + break; + } + + /* CMSPAR isn't supported by this driver */ + if (tty) + tty->termios->c_cflag &= ~CMSPAR; + + if (termios->c_cflag & CSTOPB) + cval |= UART_LCR_STOP; + if (termios->c_cflag & PARENB) + cval |= UART_LCR_PARITY; + if (!(termios->c_cflag & PARODD)) + cval |= UART_LCR_EPAR; + + /* + * The base clk is 50Mhz, and the baud rate come from: + * baud = 50M * MUL / (DIV * PS * DLAB) + * + * For those basic low baud rate we can get the direct + * scalar from 2746800, like 115200 = 2746800/24. For those + * higher baud rate, we handle them case by case, mainly by + * adjusting the MUL/PS registers, and DIV register is kept + * as default value 0x3d09 to make things simple + */ + baud = uart_get_baud_rate(port, termios, old, 0, 4000000); + + quot = 1; + ps = 0x10; + mul = 0x3600; + switch (baud) { + case 3500000: + mul = 0x3345; + ps = 0xC; + break; + case 1843200: + mul = 0x2400; + break; + case 3000000: + case 2500000: + case 2000000: + case 1500000: + case 1000000: + case 500000: + /* mul/ps/quot = 0x9C4/0x10/0x1 will make a 500000 bps */ + mul = baud / 500000 * 0x9C4; + break; + default: + /* Use uart_get_divisor to get quot for other baud rates */ + quot = 0; + } + + if (!quot) + quot = uart_get_divisor(port, baud); + + if ((up->port.uartclk / quot) < (2400 * 16)) + fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_1B; + else if ((up->port.uartclk / quot) < (230400 * 16)) + fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_16B; + else + fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_32B; + + fcr |= UART_FCR_HSU_64B_FIFO; +#ifdef MFD_HSU_A0_STEPPING + /* A0 doesn't support half empty IRQ */ + fcr |= UART_FCR_FULL_EMPT_TXI; +#endif + + /* + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ + spin_lock_irqsave(&up->port.lock, flags); + + /* Update the per-port timeout */ + uart_update_timeout(port, termios->c_cflag, baud); + + up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; + if (termios->c_iflag & INPCK) + up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE; + if (termios->c_iflag & (BRKINT | PARMRK)) + up->port.read_status_mask |= UART_LSR_BI; + + /* Characters to ignore */ + up->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; + if (termios->c_iflag & IGNBRK) { + up->port.ignore_status_mask |= UART_LSR_BI; + /* + * If we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + up->port.ignore_status_mask |= UART_LSR_OE; + } + + /* Ignore all characters if CREAD is not set */ + if ((termios->c_cflag & CREAD) == 0) + up->port.ignore_status_mask |= UART_LSR_DR; + + /* + * CTS flow control flag and modem status interrupts, disable + * MSI by default + */ + up->ier &= ~UART_IER_MSI; + if (UART_ENABLE_MS(&up->port, termios->c_cflag)) + up->ier |= UART_IER_MSI; + + serial_out(up, UART_IER, up->ier); + + if (termios->c_cflag & CRTSCTS) + up->mcr |= UART_MCR_AFE | UART_MCR_RTS; + else + up->mcr &= ~UART_MCR_AFE; + + serial_out(up, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */ + serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */ + serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */ + serial_out(up, UART_LCR, cval); /* reset DLAB */ + serial_out(up, UART_MUL, mul); /* set MUL */ + serial_out(up, UART_PS, ps); /* set PS */ + up->lcr = cval; /* Save LCR */ + serial_hsu_set_mctrl(&up->port, up->port.mctrl); + serial_out(up, UART_FCR, fcr); + spin_unlock_irqrestore(&up->port.lock, flags); +} + +static void +serial_hsu_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ +} + +static void serial_hsu_release_port(struct uart_port *port) +{ +} + +static int serial_hsu_request_port(struct uart_port *port) +{ + return 0; +} + +static void serial_hsu_config_port(struct uart_port *port, int flags) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + up->port.type = PORT_MFD; +} + +static int +serial_hsu_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + /* We don't want the core code to modify any port params */ + return -EINVAL; +} + +static const char * +serial_hsu_type(struct uart_port *port) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + return up->name; +} + +/* Mainly for uart console use */ +static struct uart_hsu_port *serial_hsu_ports[3]; +static struct uart_driver serial_hsu_reg; + +#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE + +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) + +/* Wait for transmitter & holding register to empty */ +static inline void wait_for_xmitr(struct uart_hsu_port *up) +{ + unsigned int status, tmout = 1000; + + /* Wait up to 1ms for the character to be sent. */ + do { + status = serial_in(up, UART_LSR); + + if (status & UART_LSR_BI) + up->lsr_break_flag = UART_LSR_BI; + + if (--tmout == 0) + break; + udelay(1); + } while (!(status & BOTH_EMPTY)); + + /* Wait up to 1s for flow control if necessary */ + if (up->port.flags & UPF_CONS_FLOW) { + tmout = 1000000; + while (--tmout && + ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0)) + udelay(1); + } +} + +static void serial_hsu_console_putchar(struct uart_port *port, int ch) +{ + struct uart_hsu_port *up = + container_of(port, struct uart_hsu_port, port); + + wait_for_xmitr(up); + serial_out(up, UART_TX, ch); +} + +/* + * Print a string to the serial port trying not to disturb + * any possible real use of the port... + * + * The console_lock must be held when we get here. + */ +static void +serial_hsu_console_write(struct console *co, const char *s, unsigned int count) +{ + struct uart_hsu_port *up = serial_hsu_ports[co->index]; + unsigned long flags; + unsigned int ier; + int locked = 1; + + local_irq_save(flags); + if (up->port.sysrq) + locked = 0; + else if (oops_in_progress) { + locked = spin_trylock(&up->port.lock); + } else + spin_lock(&up->port.lock); + + /* First save the IER then disable the interrupts */ + ier = serial_in(up, UART_IER); + serial_out(up, UART_IER, 0); + + uart_console_write(&up->port, s, count, serial_hsu_console_putchar); + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(up); + serial_out(up, UART_IER, ier); + + if (locked) + spin_unlock(&up->port.lock); + local_irq_restore(flags); +} + +static struct console serial_hsu_console; + +static int __init +serial_hsu_console_setup(struct console *co, char *options) +{ + struct uart_hsu_port *up; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + int ret; + + if (co->index == -1 || co->index >= serial_hsu_reg.nr) + co->index = 0; + up = serial_hsu_ports[co->index]; + if (!up) + return -ENODEV; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + ret = uart_set_options(&up->port, co, baud, parity, bits, flow); + + return ret; +} + +static struct console serial_hsu_console = { + .name = "ttyMFD", + .write = serial_hsu_console_write, + .device = uart_console_device, + .setup = serial_hsu_console_setup, + .flags = CON_PRINTBUFFER, + .index = 2, + .data = &serial_hsu_reg, +}; +#endif + +struct uart_ops serial_hsu_pops = { + .tx_empty = serial_hsu_tx_empty, + .set_mctrl = serial_hsu_set_mctrl, + .get_mctrl = serial_hsu_get_mctrl, + .stop_tx = serial_hsu_stop_tx, + .start_tx = serial_hsu_start_tx, + .stop_rx = serial_hsu_stop_rx, + .enable_ms = serial_hsu_enable_ms, + .break_ctl = serial_hsu_break_ctl, + .startup = serial_hsu_startup, + .shutdown = serial_hsu_shutdown, + .set_termios = serial_hsu_set_termios, + .pm = serial_hsu_pm, + .type = serial_hsu_type, + .release_port = serial_hsu_release_port, + .request_port = serial_hsu_request_port, + .config_port = serial_hsu_config_port, + .verify_port = serial_hsu_verify_port, +}; + +static struct uart_driver serial_hsu_reg = { + .owner = THIS_MODULE, + .driver_name = "MFD serial", + .dev_name = "ttyMFD", + .major = TTY_MAJOR, + .minor = 128, + .nr = 3, +}; + +#ifdef CONFIG_PM +static int serial_hsu_suspend(struct pci_dev *pdev, pm_message_t state) +{ + void *priv = pci_get_drvdata(pdev); + struct uart_hsu_port *up; + + /* Make sure this is not the internal dma controller */ + if (priv && (pdev->device != 0x081E)) { + up = priv; + uart_suspend_port(&serial_hsu_reg, &up->port); + } + + pci_save_state(pdev); + pci_set_power_state(pdev, pci_choose_state(pdev, state)); + return 0; +} + +static int serial_hsu_resume(struct pci_dev *pdev) +{ + void *priv = pci_get_drvdata(pdev); + struct uart_hsu_port *up; + int ret; + + pci_set_power_state(pdev, PCI_D0); + pci_restore_state(pdev); + + ret = pci_enable_device(pdev); + if (ret) + dev_warn(&pdev->dev, + "HSU: can't re-enable device, try to continue\n"); + + if (priv && (pdev->device != 0x081E)) { + up = priv; + uart_resume_port(&serial_hsu_reg, &up->port); + } + return 0; +} +#else +#define serial_hsu_suspend NULL +#define serial_hsu_resume NULL +#endif + +/* temp global pointer before we settle down on using one or four PCI dev */ +static struct hsu_port *phsu; + +static int serial_hsu_probe(struct pci_dev *pdev, + const struct pci_device_id *ent) +{ + struct uart_hsu_port *uport; + int index, ret; + + printk(KERN_INFO "HSU: found PCI Serial controller(ID: %04x:%04x)\n", + pdev->vendor, pdev->device); + + switch (pdev->device) { + case 0x081B: + index = 0; + break; + case 0x081C: + index = 1; + break; + case 0x081D: + index = 2; + break; + case 0x081E: + /* internal DMA controller */ + index = 3; + break; + default: + dev_err(&pdev->dev, "HSU: out of index!"); + return -ENODEV; + } + + ret = pci_enable_device(pdev); + if (ret) + return ret; + + if (index == 3) { + /* DMA controller */ + ret = request_irq(pdev->irq, dma_irq, 0, "hsu_dma", phsu); + if (ret) { + dev_err(&pdev->dev, "can not get IRQ\n"); + goto err_disable; + } + pci_set_drvdata(pdev, phsu); + } else { + /* UART port 0~2 */ + uport = &phsu->port[index]; + uport->port.irq = pdev->irq; + uport->port.dev = &pdev->dev; + uport->dev = &pdev->dev; + + ret = request_irq(pdev->irq, port_irq, 0, uport->name, uport); + if (ret) { + dev_err(&pdev->dev, "can not get IRQ\n"); + goto err_disable; + } + uart_add_one_port(&serial_hsu_reg, &uport->port); + +#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE + if (index == 2) { + register_console(&serial_hsu_console); + uport->port.cons = &serial_hsu_console; + } +#endif + pci_set_drvdata(pdev, uport); + } + + return 0; + +err_disable: + pci_disable_device(pdev); + return ret; +} + +static void hsu_dma_rx_timeout(unsigned long data) +{ + struct hsu_dma_chan *chan = (void *)data; + struct uart_hsu_port *up = chan->uport; + struct hsu_dma_buffer *dbuf = &up->rxbuf; + int count = 0; + unsigned long flags; + + spin_lock_irqsave(&up->port.lock, flags); + + count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr; + + if (!count) { + mod_timer(&chan->rx_timer, jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ); + goto exit; + } + + hsu_dma_rx(up, 0); +exit: + spin_unlock_irqrestore(&up->port.lock, flags); +} + +static void hsu_global_init(void) +{ + struct hsu_port *hsu; + struct uart_hsu_port *uport; + struct hsu_dma_chan *dchan; + int i, ret; + + hsu = kzalloc(sizeof(struct hsu_port), GFP_KERNEL); + if (!hsu) + return; + + /* Get basic io resource and map it */ + hsu->paddr = 0xffa28000; + hsu->iolen = 0x1000; + + if (!(request_mem_region(hsu->paddr, hsu->iolen, "HSU global"))) + pr_warning("HSU: error in request mem region\n"); + + hsu->reg = ioremap_nocache((unsigned long)hsu->paddr, hsu->iolen); + if (!hsu->reg) { + pr_err("HSU: error in ioremap\n"); + ret = -ENOMEM; + goto err_free_region; + } + + /* Initialise the 3 UART ports */ + uport = hsu->port; + for (i = 0; i < 3; i++) { + uport->port.type = PORT_MFD; + uport->port.iotype = UPIO_MEM; + uport->port.mapbase = (resource_size_t)hsu->paddr + + HSU_PORT_REG_OFFSET + + i * HSU_PORT_REG_LENGTH; + uport->port.membase = hsu->reg + HSU_PORT_REG_OFFSET + + i * HSU_PORT_REG_LENGTH; + + sprintf(uport->name, "hsu_port%d", i); + uport->port.fifosize = 64; + uport->port.ops = &serial_hsu_pops; + uport->port.line = i; + uport->port.flags = UPF_IOREMAP; + /* set the scalable maxim support rate to 2746800 bps */ + uport->port.uartclk = 115200 * 24 * 16; + + uport->running = 0; + uport->txc = &hsu->chans[i * 2]; + uport->rxc = &hsu->chans[i * 2 + 1]; + + serial_hsu_ports[i] = uport; + uport->index = i; + uport++; + } + + /* Initialise 6 dma channels */ + dchan = hsu->chans; + for (i = 0; i < 6; i++) { + dchan->id = i; + dchan->dirt = (i & 0x1) ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + dchan->uport = &hsu->port[i/2]; + dchan->reg = hsu->reg + HSU_DMA_CHANS_REG_OFFSET + + i * HSU_DMA_CHANS_REG_LENGTH; + + /* Work around for RX */ + if (dchan->dirt == DMA_FROM_DEVICE) { + init_timer(&dchan->rx_timer); + dchan->rx_timer.function = hsu_dma_rx_timeout; + dchan->rx_timer.data = (unsigned long)dchan; + } + dchan++; + } + + phsu = hsu; + hsu_debugfs_init(hsu); + return; + +err_free_region: + release_mem_region(hsu->paddr, hsu->iolen); + kfree(hsu); + return; +} + +static void serial_hsu_remove(struct pci_dev *pdev) +{ + void *priv = pci_get_drvdata(pdev); + struct uart_hsu_port *up; + + if (!priv) + return; + + /* For port 0/1/2, priv is the address of uart_hsu_port */ + if (pdev->device != 0x081E) { + up = priv; + uart_remove_one_port(&serial_hsu_reg, &up->port); + } + + pci_set_drvdata(pdev, NULL); + free_irq(pdev->irq, priv); + pci_disable_device(pdev); +} + +/* First 3 are UART ports, and the 4th is the DMA */ +static const struct pci_device_id pci_ids[] __devinitdata = { + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081B) }, + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081C) }, + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081D) }, + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081E) }, + {}, +}; + +static struct pci_driver hsu_pci_driver = { + .name = "HSU serial", + .id_table = pci_ids, + .probe = serial_hsu_probe, + .remove = __devexit_p(serial_hsu_remove), + .suspend = serial_hsu_suspend, + .resume = serial_hsu_resume, +}; + +static int __init hsu_pci_init(void) +{ + int ret; + + hsu_global_init(); + + ret = uart_register_driver(&serial_hsu_reg); + if (ret) + return ret; + + return pci_register_driver(&hsu_pci_driver); +} + +static void __exit hsu_pci_exit(void) +{ + pci_unregister_driver(&hsu_pci_driver); + uart_unregister_driver(&serial_hsu_reg); + + hsu_debugfs_remove(phsu); + + kfree(phsu); +} + +module_init(hsu_pci_init); +module_exit(hsu_pci_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:medfield-hsu"); |
