diff options
Diffstat (limited to 'drivers/tty/serial/etraxfs-uart.c')
| -rw-r--r-- | drivers/tty/serial/etraxfs-uart.c | 996 |
1 files changed, 996 insertions, 0 deletions
diff --git a/drivers/tty/serial/etraxfs-uart.c b/drivers/tty/serial/etraxfs-uart.c new file mode 100644 index 000000000..a57301a6f --- /dev/null +++ b/drivers/tty/serial/etraxfs-uart.c @@ -0,0 +1,996 @@ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/platform_device.h> +#include <linux/serial_core.h> +#include <linux/tty_flip.h> +#include <linux/of.h> +#include <linux/gpio.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> +#include <hwregs/ser_defs.h> + +#define DRV_NAME "etraxfs-uart" +#define UART_NR CONFIG_ETRAX_SERIAL_PORTS + +#define MODIFY_REG(instance, reg, var) \ + do { \ + if (REG_RD_INT(ser, instance, reg) != \ + REG_TYPE_CONV(int, reg_ser_##reg, var)) \ + REG_WR(ser, instance, reg, var); \ + } while (0) + +struct uart_cris_port { + struct uart_port port; + + int initialized; + int irq; + + void __iomem *regi_ser; + + struct gpio_desc *dtr_pin; + struct gpio_desc *dsr_pin; + struct gpio_desc *ri_pin; + struct gpio_desc *cd_pin; + + int write_ongoing; +}; + +static struct uart_driver etraxfs_uart_driver; +static struct uart_port *console_port; +static int console_baud = 115200; +static struct uart_cris_port *etraxfs_uart_ports[UART_NR]; + +static void cris_serial_port_init(struct uart_port *port, int line); +static void etraxfs_uart_stop_rx(struct uart_port *port); +static inline void etraxfs_uart_start_tx_bottom(struct uart_port *port); + +#ifdef CONFIG_SERIAL_ETRAXFS_CONSOLE +static void +cris_console_write(struct console *co, const char *s, unsigned int count) +{ + struct uart_cris_port *up; + int i; + reg_ser_r_stat_din stat; + reg_ser_rw_tr_dma_en tr_dma_en, old; + + up = etraxfs_uart_ports[co->index]; + + if (!up) + return; + + /* Switch to manual mode. */ + tr_dma_en = old = REG_RD(ser, up->regi_ser, rw_tr_dma_en); + if (tr_dma_en.en == regk_ser_yes) { + tr_dma_en.en = regk_ser_no; + REG_WR(ser, up->regi_ser, rw_tr_dma_en, tr_dma_en); + } + + /* Send data. */ + for (i = 0; i < count; i++) { + /* LF -> CRLF */ + if (s[i] == '\n') { + do { + stat = REG_RD(ser, up->regi_ser, r_stat_din); + } while (!stat.tr_rdy); + REG_WR_INT(ser, up->regi_ser, rw_dout, '\r'); + } + /* Wait until transmitter is ready and send. */ + do { + stat = REG_RD(ser, up->regi_ser, r_stat_din); + } while (!stat.tr_rdy); + REG_WR_INT(ser, up->regi_ser, rw_dout, s[i]); + } + + /* Restore mode. */ + if (tr_dma_en.en != old.en) + REG_WR(ser, up->regi_ser, rw_tr_dma_en, old); +} + +static int __init +cris_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index < 0 || co->index >= UART_NR) + co->index = 0; + port = &etraxfs_uart_ports[co->index]->port; + console_port = port; + + co->flags |= CON_CONSDEV; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + console_baud = baud; + cris_serial_port_init(port, co->index); + uart_set_options(port, co, baud, parity, bits, flow); + + return 0; +} + +static struct tty_driver *cris_console_device(struct console *co, int *index) +{ + struct uart_driver *p = co->data; + *index = co->index; + return p->tty_driver; +} + +static struct console cris_console = { + .name = "ttyS", + .write = cris_console_write, + .device = cris_console_device, + .setup = cris_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &etraxfs_uart_driver, +}; +#endif /* CONFIG_SERIAL_ETRAXFS_CONSOLE */ + +static struct uart_driver etraxfs_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "serial", + .dev_name = "ttyS", + .major = TTY_MAJOR, + .minor = 64, + .nr = UART_NR, +#ifdef CONFIG_SERIAL_ETRAXFS_CONSOLE + .cons = &cris_console, +#endif /* CONFIG_SERIAL_ETRAXFS_CONSOLE */ +}; + +static inline int crisv32_serial_get_rts(struct uart_cris_port *up) +{ + void __iomem *regi_ser = up->regi_ser; + /* + * Return what the user has controlled rts to or + * what the pin is? (if auto_rts is used it differs during tx) + */ + reg_ser_r_stat_din rstat = REG_RD(ser, regi_ser, r_stat_din); + + return !(rstat.rts_n == regk_ser_active); +} + +/* + * A set = 0 means 3.3V on the pin, bitvalue: 0=active, 1=inactive + * 0=0V , 1=3.3V + */ +static inline void crisv32_serial_set_rts(struct uart_cris_port *up, + int set, int force) +{ + void __iomem *regi_ser = up->regi_ser; + + unsigned long flags; + reg_ser_rw_rec_ctrl rec_ctrl; + + local_irq_save(flags); + rec_ctrl = REG_RD(ser, regi_ser, rw_rec_ctrl); + + if (set) + rec_ctrl.rts_n = regk_ser_active; + else + rec_ctrl.rts_n = regk_ser_inactive; + REG_WR(ser, regi_ser, rw_rec_ctrl, rec_ctrl); + local_irq_restore(flags); +} + +static inline int crisv32_serial_get_cts(struct uart_cris_port *up) +{ + void __iomem *regi_ser = up->regi_ser; + reg_ser_r_stat_din rstat = REG_RD(ser, regi_ser, r_stat_din); + + return (rstat.cts_n == regk_ser_active); +} + +/* + * Send a single character for XON/XOFF purposes. We do it in this separate + * function instead of the alternative support port.x_char, in the ...start_tx + * function, so we don't mix up this case with possibly enabling transmission + * of queued-up data (in case that's disabled after *receiving* an XOFF or + * negative CTS). This function is used for both DMA and non-DMA case; see HW + * docs specifically blessing sending characters manually when DMA for + * transmission is enabled and running. We may be asked to transmit despite + * the transmitter being disabled by a ..._stop_tx call so we need to enable + * it temporarily but restore the state afterwards. + */ +static void etraxfs_uart_send_xchar(struct uart_port *port, char ch) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + reg_ser_rw_dout dout = { .data = ch }; + reg_ser_rw_ack_intr ack_intr = { .tr_rdy = regk_ser_yes }; + reg_ser_r_stat_din rstat; + reg_ser_rw_tr_ctrl prev_tr_ctrl, tr_ctrl; + void __iomem *regi_ser = up->regi_ser; + unsigned long flags; + + /* + * Wait for tr_rdy in case a character is already being output. Make + * sure we have integrity between the register reads and the writes + * below, but don't busy-wait with interrupts off and the port lock + * taken. + */ + spin_lock_irqsave(&port->lock, flags); + do { + spin_unlock_irqrestore(&port->lock, flags); + spin_lock_irqsave(&port->lock, flags); + prev_tr_ctrl = tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl); + rstat = REG_RD(ser, regi_ser, r_stat_din); + } while (!rstat.tr_rdy); + + /* + * Ack an interrupt if one was just issued for the previous character + * that was output. This is required for non-DMA as the interrupt is + * used as the only indicator that the transmitter is ready and it + * isn't while this x_char is being transmitted. + */ + REG_WR(ser, regi_ser, rw_ack_intr, ack_intr); + + /* Enable the transmitter in case it was disabled. */ + tr_ctrl.stop = 0; + REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl); + + /* + * Finally, send the blessed character; nothing should stop it now, + * except for an xoff-detected state, which we'll handle below. + */ + REG_WR(ser, regi_ser, rw_dout, dout); + up->port.icount.tx++; + + /* There might be an xoff state to clear. */ + rstat = REG_RD(ser, up->regi_ser, r_stat_din); + + /* + * Clear any xoff state that *may* have been there to + * inhibit transmission of the character. + */ + if (rstat.xoff_detect) { + reg_ser_rw_xoff_clr xoff_clr = { .clr = 1 }; + reg_ser_rw_tr_dma_en tr_dma_en; + + REG_WR(ser, regi_ser, rw_xoff_clr, xoff_clr); + tr_dma_en = REG_RD(ser, regi_ser, rw_tr_dma_en); + + /* + * If we had an xoff state but cleared it, instead sneak in a + * disabled state for the transmitter, after the character we + * sent. Thus we keep the port disabled, just as if the xoff + * state was still in effect (or actually, as if stop_tx had + * been called, as we stop DMA too). + */ + prev_tr_ctrl.stop = 1; + + tr_dma_en.en = 0; + REG_WR(ser, regi_ser, rw_tr_dma_en, tr_dma_en); + } + + /* Restore "previous" enabled/disabled state of the transmitter. */ + REG_WR(ser, regi_ser, rw_tr_ctrl, prev_tr_ctrl); + + spin_unlock_irqrestore(&port->lock, flags); +} + +/* + * Do not spin_lock_irqsave or disable interrupts by other means here; it's + * already done by the caller. + */ +static void etraxfs_uart_start_tx(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + + /* we have already done below if a write is ongoing */ + if (up->write_ongoing) + return; + + /* Signal that write is ongoing */ + up->write_ongoing = 1; + + etraxfs_uart_start_tx_bottom(port); +} + +static inline void etraxfs_uart_start_tx_bottom(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + void __iomem *regi_ser = up->regi_ser; + reg_ser_rw_tr_ctrl tr_ctrl; + reg_ser_rw_intr_mask intr_mask; + + tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl); + tr_ctrl.stop = regk_ser_no; + REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl); + intr_mask = REG_RD(ser, regi_ser, rw_intr_mask); + intr_mask.tr_rdy = regk_ser_yes; + REG_WR(ser, regi_ser, rw_intr_mask, intr_mask); +} + +/* + * This function handles both the DMA and non-DMA case by ordering the + * transmitter to stop of after the current character. We don't need to wait + * for any such character to be completely transmitted; we do that where it + * matters, like in etraxfs_uart_set_termios. Don't busy-wait here; see + * Documentation/serial/driver: this function is called within + * spin_lock_irq{,save} and thus separate ones would be disastrous (when SMP). + * There's no documented need to set the txd pin to any particular value; + * break setting is controlled solely by etraxfs_uart_break_ctl. + */ +static void etraxfs_uart_stop_tx(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + void __iomem *regi_ser = up->regi_ser; + reg_ser_rw_tr_ctrl tr_ctrl; + reg_ser_rw_intr_mask intr_mask; + reg_ser_rw_tr_dma_en tr_dma_en = {0}; + reg_ser_rw_xoff_clr xoff_clr = {0}; + + /* + * For the non-DMA case, we'd get a tr_rdy interrupt that we're not + * interested in as we're not transmitting any characters. For the + * DMA case, that interrupt is already turned off, but no reason to + * waste code on conditionals here. + */ + intr_mask = REG_RD(ser, regi_ser, rw_intr_mask); + intr_mask.tr_rdy = regk_ser_no; + REG_WR(ser, regi_ser, rw_intr_mask, intr_mask); + + tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl); + tr_ctrl.stop = 1; + REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl); + + /* + * Always clear possible hardware xoff-detected state here, no need to + * unnecessary consider mctrl settings and when they change. We clear + * it here rather than in start_tx: both functions are called as the + * effect of XOFF processing, but start_tx is also called when upper + * levels tell the driver that there are more characters to send, so + * avoid adding code there. + */ + xoff_clr.clr = 1; + REG_WR(ser, regi_ser, rw_xoff_clr, xoff_clr); + + /* + * Disable transmitter DMA, so that if we're in XON/XOFF, we can send + * those single characters without also giving go-ahead for queued up + * DMA data. + */ + tr_dma_en.en = 0; + REG_WR(ser, regi_ser, rw_tr_dma_en, tr_dma_en); + + /* + * Make sure that write_ongoing is reset when stopping tx. + */ + up->write_ongoing = 0; +} + +static void etraxfs_uart_stop_rx(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + void __iomem *regi_ser = up->regi_ser; + reg_ser_rw_rec_ctrl rec_ctrl = REG_RD(ser, regi_ser, rw_rec_ctrl); + + rec_ctrl.en = regk_ser_no; + REG_WR(ser, regi_ser, rw_rec_ctrl, rec_ctrl); +} + +static void etraxfs_uart_enable_ms(struct uart_port *port) +{ +} + +static void check_modem_status(struct uart_cris_port *up) +{ +} + +static unsigned int etraxfs_uart_tx_empty(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + unsigned long flags; + unsigned int ret; + reg_ser_r_stat_din rstat = {0}; + + spin_lock_irqsave(&up->port.lock, flags); + + rstat = REG_RD(ser, up->regi_ser, r_stat_din); + ret = rstat.tr_empty ? TIOCSER_TEMT : 0; + + spin_unlock_irqrestore(&up->port.lock, flags); + return ret; +} +static unsigned int etraxfs_uart_get_mctrl(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + unsigned int ret; + + ret = 0; + if (crisv32_serial_get_rts(up)) + ret |= TIOCM_RTS; + /* DTR is active low */ + if (up->dtr_pin && !gpiod_get_raw_value(up->dtr_pin)) + ret |= TIOCM_DTR; + /* CD is active low */ + if (up->cd_pin && !gpiod_get_raw_value(up->cd_pin)) + ret |= TIOCM_CD; + /* RI is active low */ + if (up->ri_pin && !gpiod_get_raw_value(up->ri_pin)) + ret |= TIOCM_RI; + /* DSR is active low */ + if (up->dsr_pin && !gpiod_get_raw_value(up->dsr_pin)) + ret |= TIOCM_DSR; + if (crisv32_serial_get_cts(up)) + ret |= TIOCM_CTS; + return ret; +} + +static void etraxfs_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + + crisv32_serial_set_rts(up, mctrl & TIOCM_RTS ? 1 : 0, 0); + /* DTR is active low */ + if (up->dtr_pin) + gpiod_set_raw_value(up->dtr_pin, mctrl & TIOCM_DTR ? 0 : 1); + /* RI is active low */ + if (up->ri_pin) + gpiod_set_raw_value(up->ri_pin, mctrl & TIOCM_RNG ? 0 : 1); + /* CD is active low */ + if (up->cd_pin) + gpiod_set_raw_value(up->cd_pin, mctrl & TIOCM_CD ? 0 : 1); +} + +static void etraxfs_uart_break_ctl(struct uart_port *port, int break_state) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + unsigned long flags; + reg_ser_rw_tr_ctrl tr_ctrl; + reg_ser_rw_tr_dma_en tr_dma_en; + reg_ser_rw_intr_mask intr_mask; + + spin_lock_irqsave(&up->port.lock, flags); + tr_ctrl = REG_RD(ser, up->regi_ser, rw_tr_ctrl); + tr_dma_en = REG_RD(ser, up->regi_ser, rw_tr_dma_en); + intr_mask = REG_RD(ser, up->regi_ser, rw_intr_mask); + + if (break_state != 0) { /* Send break */ + /* + * We need to disable DMA (if used) or tr_rdy interrupts if no + * DMA. No need to make this conditional on use of DMA; + * disabling will be a no-op for the other mode. + */ + intr_mask.tr_rdy = regk_ser_no; + tr_dma_en.en = 0; + + /* + * Stop transmission and set the txd pin to 0 after the + * current character. The txd setting will take effect after + * any current transmission has completed. + */ + tr_ctrl.stop = 1; + tr_ctrl.txd = 0; + } else { + /* Re-enable the serial interrupt. */ + intr_mask.tr_rdy = regk_ser_yes; + + tr_ctrl.stop = 0; + tr_ctrl.txd = 1; + } + REG_WR(ser, up->regi_ser, rw_tr_ctrl, tr_ctrl); + REG_WR(ser, up->regi_ser, rw_tr_dma_en, tr_dma_en); + REG_WR(ser, up->regi_ser, rw_intr_mask, intr_mask); + + spin_unlock_irqrestore(&up->port.lock, flags); +} + +static void +transmit_chars_no_dma(struct uart_cris_port *up) +{ + int max_count; + struct circ_buf *xmit = &up->port.state->xmit; + + void __iomem *regi_ser = up->regi_ser; + reg_ser_r_stat_din rstat; + reg_ser_rw_ack_intr ack_intr = { .tr_rdy = regk_ser_yes }; + + if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { + /* No more to send, so disable the interrupt. */ + reg_ser_rw_intr_mask intr_mask; + + intr_mask = REG_RD(ser, regi_ser, rw_intr_mask); + intr_mask.tr_rdy = 0; + intr_mask.tr_empty = 0; + REG_WR(ser, regi_ser, rw_intr_mask, intr_mask); + up->write_ongoing = 0; + return; + } + + /* If the serport is fast, we send up to max_count bytes before + exiting the loop. */ + max_count = 64; + do { + reg_ser_rw_dout dout = { .data = xmit->buf[xmit->tail] }; + + REG_WR(ser, regi_ser, rw_dout, dout); + REG_WR(ser, regi_ser, rw_ack_intr, ack_intr); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1); + up->port.icount.tx++; + if (xmit->head == xmit->tail) + break; + rstat = REG_RD(ser, regi_ser, r_stat_din); + } while ((--max_count > 0) && rstat.tr_rdy); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&up->port); +} + +static void receive_chars_no_dma(struct uart_cris_port *up) +{ + reg_ser_rs_stat_din stat_din; + reg_ser_r_stat_din rstat; + struct tty_port *port; + struct uart_icount *icount; + int max_count = 16; + char flag; + reg_ser_rw_ack_intr ack_intr = { 0 }; + + rstat = REG_RD(ser, up->regi_ser, r_stat_din); + icount = &up->port.icount; + port = &up->port.state->port; + + do { + stat_din = REG_RD(ser, up->regi_ser, rs_stat_din); + + flag = TTY_NORMAL; + ack_intr.dav = 1; + REG_WR(ser, up->regi_ser, rw_ack_intr, ack_intr); + icount->rx++; + + if (stat_din.framing_err | stat_din.par_err | stat_din.orun) { + if (stat_din.data == 0x00 && + stat_din.framing_err) { + /* Most likely a break. */ + flag = TTY_BREAK; + icount->brk++; + } else if (stat_din.par_err) { + flag = TTY_PARITY; + icount->parity++; + } else if (stat_din.orun) { + flag = TTY_OVERRUN; + icount->overrun++; + } else if (stat_din.framing_err) { + flag = TTY_FRAME; + icount->frame++; + } + } + + /* + * If this becomes important, we probably *could* handle this + * gracefully by keeping track of the unhandled character. + */ + if (!tty_insert_flip_char(port, stat_din.data, flag)) + panic("%s: No tty buffer space", __func__); + rstat = REG_RD(ser, up->regi_ser, r_stat_din); + } while (rstat.dav && (max_count-- > 0)); + spin_unlock(&up->port.lock); + tty_flip_buffer_push(port); + spin_lock(&up->port.lock); +} + +static irqreturn_t +ser_interrupt(int irq, void *dev_id) +{ + struct uart_cris_port *up = (struct uart_cris_port *)dev_id; + void __iomem *regi_ser; + int handled = 0; + + spin_lock(&up->port.lock); + + regi_ser = up->regi_ser; + + if (regi_ser) { + reg_ser_r_masked_intr masked_intr; + + masked_intr = REG_RD(ser, regi_ser, r_masked_intr); + /* + * Check what interrupts are active before taking + * actions. If DMA is used the interrupt shouldn't + * be enabled. + */ + if (masked_intr.dav) { + receive_chars_no_dma(up); + handled = 1; + } + check_modem_status(up); + + if (masked_intr.tr_rdy) { + transmit_chars_no_dma(up); + handled = 1; + } + } + spin_unlock(&up->port.lock); + return IRQ_RETVAL(handled); +} + +#ifdef CONFIG_CONSOLE_POLL +static int etraxfs_uart_get_poll_char(struct uart_port *port) +{ + reg_ser_rs_stat_din stat; + reg_ser_rw_ack_intr ack_intr = { 0 }; + struct uart_cris_port *up = (struct uart_cris_port *)port; + + do { + stat = REG_RD(ser, up->regi_ser, rs_stat_din); + } while (!stat.dav); + + /* Ack the data_avail interrupt. */ + ack_intr.dav = 1; + REG_WR(ser, up->regi_ser, rw_ack_intr, ack_intr); + + return stat.data; +} + +static void etraxfs_uart_put_poll_char(struct uart_port *port, + unsigned char c) +{ + reg_ser_r_stat_din stat; + struct uart_cris_port *up = (struct uart_cris_port *)port; + + do { + stat = REG_RD(ser, up->regi_ser, r_stat_din); + } while (!stat.tr_rdy); + REG_WR_INT(ser, up->regi_ser, rw_dout, c); +} +#endif /* CONFIG_CONSOLE_POLL */ + +static int etraxfs_uart_startup(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + unsigned long flags; + reg_ser_rw_intr_mask ser_intr_mask = {0}; + + ser_intr_mask.dav = regk_ser_yes; + + if (request_irq(etraxfs_uart_ports[port->line]->irq, ser_interrupt, + 0, DRV_NAME, etraxfs_uart_ports[port->line])) + panic("irq ser%d", port->line); + + spin_lock_irqsave(&up->port.lock, flags); + + REG_WR(ser, up->regi_ser, rw_intr_mask, ser_intr_mask); + + etraxfs_uart_set_mctrl(&up->port, up->port.mctrl); + + spin_unlock_irqrestore(&up->port.lock, flags); + + return 0; +} + +static void etraxfs_uart_shutdown(struct uart_port *port) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + unsigned long flags; + + spin_lock_irqsave(&up->port.lock, flags); + + etraxfs_uart_stop_tx(port); + etraxfs_uart_stop_rx(port); + + free_irq(etraxfs_uart_ports[port->line]->irq, + etraxfs_uart_ports[port->line]); + + etraxfs_uart_set_mctrl(&up->port, up->port.mctrl); + + spin_unlock_irqrestore(&up->port.lock, flags); + +} + +static void +etraxfs_uart_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + unsigned long flags; + reg_ser_rw_xoff xoff; + reg_ser_rw_xoff_clr xoff_clr = {0}; + reg_ser_rw_tr_ctrl tx_ctrl = {0}; + reg_ser_rw_tr_dma_en tx_dma_en = {0}; + reg_ser_rw_rec_ctrl rx_ctrl = {0}; + reg_ser_rw_tr_baud_div tx_baud_div = {0}; + reg_ser_rw_rec_baud_div rx_baud_div = {0}; + int baud; + + if (old && + termios->c_cflag == old->c_cflag && + termios->c_iflag == old->c_iflag) + return; + + /* Tx: 8 bit, no/even parity, 1 stop bit, no cts. */ + tx_ctrl.base_freq = regk_ser_f29_493; + tx_ctrl.en = 0; + tx_ctrl.stop = 0; + tx_ctrl.auto_rts = regk_ser_no; + tx_ctrl.txd = 1; + tx_ctrl.auto_cts = 0; + /* Rx: 8 bit, no/even parity. */ + rx_ctrl.dma_err = regk_ser_stop; + rx_ctrl.sampling = regk_ser_majority; + rx_ctrl.timeout = 1; + + rx_ctrl.rts_n = regk_ser_inactive; + + /* Common for tx and rx: 8N1. */ + tx_ctrl.data_bits = regk_ser_bits8; + rx_ctrl.data_bits = regk_ser_bits8; + tx_ctrl.par = regk_ser_even; + rx_ctrl.par = regk_ser_even; + tx_ctrl.par_en = regk_ser_no; + rx_ctrl.par_en = regk_ser_no; + + tx_ctrl.stop_bits = regk_ser_bits1; + + /* + * Change baud-rate and write it to the hardware. + * + * baud_clock = base_freq / (divisor*8) + * divisor = base_freq / (baud_clock * 8) + * base_freq is either: + * off, ext, 29.493MHz, 32.000 MHz, 32.768 MHz or 100 MHz + * 20.493MHz is used for standard baudrates + */ + + /* + * For the console port we keep the original baudrate here. Not very + * beautiful. + */ + if ((port != console_port) || old) + baud = uart_get_baud_rate(port, termios, old, 0, + port->uartclk / 8); + else + baud = console_baud; + + tx_baud_div.div = 29493000 / (8 * baud); + /* Rx uses same as tx. */ + rx_baud_div.div = tx_baud_div.div; + rx_ctrl.base_freq = tx_ctrl.base_freq; + + if ((termios->c_cflag & CSIZE) == CS7) { + /* Set 7 bit mode. */ + tx_ctrl.data_bits = regk_ser_bits7; + rx_ctrl.data_bits = regk_ser_bits7; + } + + if (termios->c_cflag & CSTOPB) { + /* Set 2 stop bit mode. */ + tx_ctrl.stop_bits = regk_ser_bits2; + } + + if (termios->c_cflag & PARENB) { + /* Enable parity. */ + tx_ctrl.par_en = regk_ser_yes; + rx_ctrl.par_en = regk_ser_yes; + } + + if (termios->c_cflag & CMSPAR) { + if (termios->c_cflag & PARODD) { + /* Set mark parity if PARODD and CMSPAR. */ + tx_ctrl.par = regk_ser_mark; + rx_ctrl.par = regk_ser_mark; + } else { + tx_ctrl.par = regk_ser_space; + rx_ctrl.par = regk_ser_space; + } + } else { + if (termios->c_cflag & PARODD) { + /* Set odd parity. */ + tx_ctrl.par = regk_ser_odd; + rx_ctrl.par = regk_ser_odd; + } + } + + if (termios->c_cflag & CRTSCTS) { + /* Enable automatic CTS handling. */ + tx_ctrl.auto_cts = regk_ser_yes; + } + + /* Make sure the tx and rx are enabled. */ + tx_ctrl.en = regk_ser_yes; + rx_ctrl.en = regk_ser_yes; + + spin_lock_irqsave(&port->lock, flags); + + tx_dma_en.en = 0; + REG_WR(ser, up->regi_ser, rw_tr_dma_en, tx_dma_en); + + /* Actually write the control regs (if modified) to the hardware. */ + uart_update_timeout(port, termios->c_cflag, port->uartclk/8); + MODIFY_REG(up->regi_ser, rw_rec_baud_div, rx_baud_div); + MODIFY_REG(up->regi_ser, rw_rec_ctrl, rx_ctrl); + + MODIFY_REG(up->regi_ser, rw_tr_baud_div, tx_baud_div); + MODIFY_REG(up->regi_ser, rw_tr_ctrl, tx_ctrl); + + tx_dma_en.en = 0; + REG_WR(ser, up->regi_ser, rw_tr_dma_en, tx_dma_en); + + xoff = REG_RD(ser, up->regi_ser, rw_xoff); + + if (up->port.state && up->port.state->port.tty && + (up->port.state->port.tty->termios.c_iflag & IXON)) { + xoff.chr = STOP_CHAR(up->port.state->port.tty); + xoff.automatic = regk_ser_yes; + } else + xoff.automatic = regk_ser_no; + + MODIFY_REG(up->regi_ser, rw_xoff, xoff); + + /* + * Make sure we don't start in an automatically shut-off state due to + * a previous early exit. + */ + xoff_clr.clr = 1; + REG_WR(ser, up->regi_ser, rw_xoff_clr, xoff_clr); + + etraxfs_uart_set_mctrl(&up->port, up->port.mctrl); + spin_unlock_irqrestore(&up->port.lock, flags); +} + +static const char * +etraxfs_uart_type(struct uart_port *port) +{ + return "CRISv32"; +} + +static void etraxfs_uart_release_port(struct uart_port *port) +{ +} + +static int etraxfs_uart_request_port(struct uart_port *port) +{ + return 0; +} + +static void etraxfs_uart_config_port(struct uart_port *port, int flags) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + + up->port.type = PORT_CRIS; +} + +static const struct uart_ops etraxfs_uart_pops = { + .tx_empty = etraxfs_uart_tx_empty, + .set_mctrl = etraxfs_uart_set_mctrl, + .get_mctrl = etraxfs_uart_get_mctrl, + .stop_tx = etraxfs_uart_stop_tx, + .start_tx = etraxfs_uart_start_tx, + .send_xchar = etraxfs_uart_send_xchar, + .stop_rx = etraxfs_uart_stop_rx, + .enable_ms = etraxfs_uart_enable_ms, + .break_ctl = etraxfs_uart_break_ctl, + .startup = etraxfs_uart_startup, + .shutdown = etraxfs_uart_shutdown, + .set_termios = etraxfs_uart_set_termios, + .type = etraxfs_uart_type, + .release_port = etraxfs_uart_release_port, + .request_port = etraxfs_uart_request_port, + .config_port = etraxfs_uart_config_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = etraxfs_uart_get_poll_char, + .poll_put_char = etraxfs_uart_put_poll_char, +#endif +}; + +static void cris_serial_port_init(struct uart_port *port, int line) +{ + struct uart_cris_port *up = (struct uart_cris_port *)port; + + if (up->initialized) + return; + up->initialized = 1; + port->line = line; + spin_lock_init(&port->lock); + port->ops = &etraxfs_uart_pops; + port->irq = up->irq; + port->iobase = (unsigned long) up->regi_ser; + port->uartclk = 29493000; + + /* + * We can't fit any more than 255 here (unsigned char), though + * actually UART_XMIT_SIZE characters could be pending output. + * At time of this writing, the definition of "fifosize" is here the + * amount of characters that can be pending output after a start_tx call + * until tx_empty returns 1: see serial_core.c:uart_wait_until_sent. + * This matters for timeout calculations unfortunately, but keeping + * larger amounts at the DMA wouldn't win much so let's just play nice. + */ + port->fifosize = 255; + port->flags = UPF_BOOT_AUTOCONF; +} + +static int etraxfs_uart_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct uart_cris_port *up; + int dev_id; + + if (!np) + return -ENODEV; + + dev_id = of_alias_get_id(np, "serial"); + if (dev_id < 0) + dev_id = 0; + + if (dev_id >= UART_NR) + return -EINVAL; + + if (etraxfs_uart_ports[dev_id]) + return -EBUSY; + + up = devm_kzalloc(&pdev->dev, sizeof(struct uart_cris_port), + GFP_KERNEL); + if (!up) + return -ENOMEM; + + up->irq = irq_of_parse_and_map(np, 0); + up->regi_ser = of_iomap(np, 0); + up->dtr_pin = devm_gpiod_get_optional(&pdev->dev, "dtr"); + up->dsr_pin = devm_gpiod_get_optional(&pdev->dev, "dsr"); + up->ri_pin = devm_gpiod_get_optional(&pdev->dev, "ri"); + up->cd_pin = devm_gpiod_get_optional(&pdev->dev, "cd"); + up->port.dev = &pdev->dev; + cris_serial_port_init(&up->port, dev_id); + + etraxfs_uart_ports[dev_id] = up; + platform_set_drvdata(pdev, &up->port); + uart_add_one_port(&etraxfs_uart_driver, &up->port); + + return 0; +} + +static int etraxfs_uart_remove(struct platform_device *pdev) +{ + struct uart_port *port; + + port = platform_get_drvdata(pdev); + uart_remove_one_port(&etraxfs_uart_driver, port); + etraxfs_uart_ports[pdev->id] = NULL; + + return 0; +} + +static const struct of_device_id etraxfs_uart_dt_ids[] = { + { .compatible = "axis,etraxfs-uart" }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, etraxfs_uart_dt_ids); + +static struct platform_driver etraxfs_uart_platform_driver = { + .driver = { + .name = DRV_NAME, + .of_match_table = of_match_ptr(etraxfs_uart_dt_ids), + }, + .probe = etraxfs_uart_probe, + .remove = etraxfs_uart_remove, +}; + +static int __init etraxfs_uart_init(void) +{ + int ret; + + ret = uart_register_driver(&etraxfs_uart_driver); + if (ret) + return ret; + + ret = platform_driver_register(&etraxfs_uart_platform_driver); + if (ret) + uart_unregister_driver(&etraxfs_uart_driver); + + return ret; +} + +static void __exit etraxfs_uart_exit(void) +{ + platform_driver_unregister(&etraxfs_uart_platform_driver); + uart_unregister_driver(&etraxfs_uart_driver); +} + +module_init(etraxfs_uart_init); +module_exit(etraxfs_uart_exit); 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