Signed-off-by: Niklas Cassel <nks@xxxxxxxxxxx>
---
This is the last missing piece to get a kernel booting to a prompt in qemu-cris.
Patches adding device tree support for arch/cris will be submitted soon.
drivers/tty/serial/Kconfig | 10 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/etraxfs-uart.c | 996 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/serial_core.h | 3 +
4 files changed, 1010 insertions(+)
create mode 100644 drivers/tty/serial/etraxfs-uart.c
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 59332af..fd571b6 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1094,6 +1094,16 @@ config SERIAL_VT8500_CONSOLE
depends on SERIAL_VT8500=y
select SERIAL_CORE_CONSOLE
+config SERIAL_ETRAXFS
+ bool "ETRAX FS serial port support"
+ depends on ETRAX_ARCH_V32 && OF
+ select SERIAL_CORE
+
+config SERIAL_ETRAXFS_CONSOLE
+ bool "ETRAX FS serial console support"
+ depends on SERIAL_ETRAXFS
+ select SERIAL_CORE_CONSOLE
+
config SERIAL_NETX
tristate "NetX serial port support"
depends on ARCH_NETX
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 770a19b..ba497c1 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_SERIAL_MPSC) += mpsc.o
obj-$(CONFIG_SERIAL_MESON) += meson_uart.o
obj-$(CONFIG_SERIAL_SB1250_DUART) += sb1250-duart.o
obj-$(CONFIG_ETRAX_SERIAL) += crisv10.o
+obj-$(CONFIG_SERIAL_ETRAXFS) += etraxfs-uart.o
obj-$(CONFIG_SERIAL_SCCNXP) += sccnxp.o
obj-$(CONFIG_SERIAL_SC16IS7XX) += sc16is7xx.o
obj-$(CONFIG_SERIAL_JSM) += jsm/
diff --git a/drivers/tty/serial/etraxfs-uart.c b/drivers/tty/serial/etraxfs-uart.c
new file mode 100644
index 0000000..a57301a
--- /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);
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index ee628c4..96353e3 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -252,4 +252,7 @@
/* Conexant Digicolor */
#define PORT_DIGICOLOR 110
+/* Cris v10 / v32 SoC */
+#define PORT_CRIS 111
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
2.2.2
--
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