This patch adds console support for the MAX3100 UART
(console=ttyMAX0,11500). The SPI subsystem and an
suitable SPI master driver have to be compiled in the kernel.
Signed-off-by: Christian Pellegrin <chripell@xxxxxxxx>
---
drivers/serial/Kconfig | 20 +++++
drivers/serial/max3100.c | 184 +++++++++++++++++++++++++++++++++++++++++----
2 files changed, 187 insertions(+), 17 deletions(-)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 9ff47db..bc72e84 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -547,6 +547,26 @@ config SERIAL_MAX3100
help
MAX3100 chip support
+config SERIAL_MAX3100_CONSOLE
+ bool "Support console on MAX3100"
+ depends on SERIAL_MAX3100=y
+ select SERIAL_CORE_CONSOLE
+ help
+ Console on MAX3100
+
+config SERIAL_MAX3100_CONSOLE_N
+ int "Number of MAX3100 chips to wait before registering console"
+ depends on SERIAL_MAX3100_CONSOLE=y
+ default "1"
+ help
+ Unfortunately due to the async nature of Linux boot we must
+ know in advance when to register the console. If we do it
+ too early not all the MAX3100 chips are known to the system
+ yet. And we just cannot know how many MAX3100 will be in the
+ system so it's impossible to wait for the last one. If you
+ just want to have the console on the first MAX3100 chip
+ probed (ttyMAX0) it's safe to leave this to 1.
+
config SERIAL_DZ
bool "DECstation DZ serial driver"
depends on MACH_DECSTATION && 32BIT
diff --git a/drivers/serial/max3100.c b/drivers/serial/max3100.c
index 0c972c6..f6d250d 100644
--- a/drivers/serial/max3100.c
+++ b/drivers/serial/max3100.c
@@ -48,6 +48,7 @@
#include <linux/kthread.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
+#include <linux/console.h>
#include <linux/serial_max3100.h>
@@ -131,6 +132,10 @@ struct max3100_port {
int poll_time;
/* and its timer */
struct timer_list timer;
+
+ int console_flags;
+ /* is this port a console? */
+#define MAX3100_IS_CONSOLE (1 << 0)
};
static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
@@ -175,7 +180,8 @@ static void max3100_resume_work(struct work_struct *w)
struct max3100_port *s = container_of(w, struct max3100_port,
resume_work);
- raise_threaded_irq(s->irq);
+ if (s->irq)
+ raise_threaded_irq(s->irq);
}
static void max3100_timeout(unsigned long data)
@@ -552,14 +558,16 @@ static void max3100_shutdown(struct uart_port *port)
if (s->irq)
free_irq(s->irq, s);
- /* set shutdown mode to save power */
- if (s->max3100_hw_suspend)
- s->max3100_hw_suspend(1);
- else {
- u16 tx, rx;
+ if (!(s->console_flags & MAX3100_IS_CONSOLE)) {
+ /* set shutdown mode to save power */
+ if (s->max3100_hw_suspend)
+ s->max3100_hw_suspend(1);
+ else {
+ u16 tx, rx;
- tx = MAX3100_WC | MAX3100_SHDN;
- max3100_sr(s, tx, &rx);
+ tx = MAX3100_WC | MAX3100_SHDN;
+ max3100_sr(s, tx, &rx);
+ }
}
}
@@ -578,10 +586,8 @@ static int max3100_startup(struct uart_port *port)
s->parity = 0;
s->rts = 0;
- INIT_WORK(&s->resume_work, max3100_resume_work);
-
if (request_threaded_irq(s->irq, NULL, max3100_ist,
- IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
+ IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
dev_err(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
s->irq = 0;
return -EBUSY;
@@ -699,6 +705,136 @@ static struct uart_ops max3100_ops = {
.verify_port = max3100_verify_port,
};
+#ifdef CONFIG_SERIAL_MAX3100_CONSOLE
+
+static void max3100_console_putchar(struct uart_port *port, int ch)
+{
+ struct max3100_port *s = container_of(port, struct max3100_port, port);
+ unsigned long tout = 10 * HZ / 1000; /* 10ms */
+ unsigned long start;
+ u16 tx, rx;
+
+ if (tout == 0)
+ tout = 1;
+ start = jiffies;
+ do {
+ tx = MAX3100_RC;
+ max3100_sr(s, tx, &rx);
+ } while ((rx & MAX3100_T) == 0 &&
+ !time_after(jiffies, start + tout));
+ tx = ch;
+ max3100_calc_parity(s, &tx);
+ tx |= MAX3100_WD | MAX3100_RTS;
+ max3100_sr(s, tx, &rx);
+}
+
+static void max3100_console_write(struct console *co,
+ const char *str, unsigned int count)
+{
+ struct max3100_port *s = max3100s[co->index];;
+
+ uart_console_write(&s->port, str, count, max3100_console_putchar);
+}
+
+static int max3100_console_setup(struct console *co, char *options)
+{
+ struct max3100_port *s;
+ int baud = 115200;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+ int ret;
+ u16 tx, rx;
+
+ if (co->index == -1 || co->index >= MAX_MAX3100)
+ co->index = 0;
+ s = max3100s[co->index];
+ if (!s)
+ return -ENOENT;
+ s->console_flags |= MAX3100_IS_CONSOLE;
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ ret = uart_set_options(&s->port, co, baud, parity, bits, flow);
+
+ tx = 0;
+ switch (baud) {
+ case 300:
+ tx = 15;
+ break;
+ case 600:
+ tx = 14 + s->crystal;
+ break;
+ case 1200:
+ tx = 13 + s->crystal;
+ break;
+ case 2400:
+ tx = 12 + s->crystal;
+ break;
+ case 4800:
+ tx = 11 + s->crystal;
+ break;
+ case 9600:
+ tx = 10 + s->crystal;
+ break;
+ case 19200:
+ tx = 9 + s->crystal;
+ break;
+ case 38400:
+ tx = 8 + s->crystal;
+ break;
+ case 57600:
+ tx = 1 + s->crystal;
+ break;
+ case 115200:
+ tx = 0 + s->crystal;
+ break;
+ case 230400:
+ tx = 0;
+ break;
+ }
+
+ if (bits == 8) {
+ tx &= ~MAX3100_L;
+ s->parity &= ~MAX3100_7BIT;
+ } else {
+ tx |= MAX3100_L;
+ s->parity |= MAX3100_7BIT;
+ }
+
+ if (parity == 'o' || parity == 'e') {
+ tx |= MAX3100_PE;
+ parity |= MAX3100_PARITY_ON;
+ } else {
+ tx &= ~MAX3100_PE;
+ parity &= ~MAX3100_PARITY_ON;
+ }
+
+ if (parity == 'o')
+ parity |= MAX3100_PARITY_ODD;
+ else
+ parity &= ~MAX3100_PARITY_ODD;
+
+
+ tx |= MAX3100_WC;
+ max3100_sr(s, tx, &rx);
+
+ msleep(50);
+ return ret;
+}
+
+static struct uart_driver max3100_uart_driver;
+static struct console max3100_console = {
+ .name = "ttyMAX",
+ .write = max3100_console_write,
+ .device = uart_console_device,
+ .setup = max3100_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &max3100_uart_driver,
+};
+#endif
+
static struct uart_driver max3100_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "ttyMAX",
@@ -706,6 +842,9 @@ static struct uart_driver max3100_uart_driver = {
.major = MAX3100_MAJOR,
.minor = MAX3100_MINOR,
.nr = MAX_MAX3100,
+#ifdef CONFIG_SERIAL_MAX3100_CONSOLE
+ .cons = &max3100_console,
+#endif
};
static int uart_driver_registered;
@@ -768,18 +907,26 @@ static int __devinit max3100_probe(struct spi_device *spi)
max3100s[i]->port.line = i;
max3100s[i]->port.type = PORT_MAX3100;
max3100s[i]->port.dev = &spi->dev;
+ INIT_WORK(&max3100s[i]->resume_work, max3100_resume_work);
retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
if (retval < 0)
dev_warn(&spi->dev,
"uart_add_one_port failed for line %d with error %d\n",
i, retval);
- /* set shutdown mode to save power. Will be woken-up on open */
- if (max3100s[i]->max3100_hw_suspend)
- max3100s[i]->max3100_hw_suspend(1);
- else {
- tx = MAX3100_WC | MAX3100_SHDN;
- max3100_sr(max3100s[i], tx, &rx);
+#ifdef CONFIG_SERIAL_MAX3100_CONSOLE
+ if (i == (CONFIG_SERIAL_MAX3100_CONSOLE_N - 1))
+ register_console(&max3100_console);
+#endif
+
+ if (!(max3100s[i]->console_flags & MAX3100_IS_CONSOLE)) {
+ /* set shutdown mode to save power. Will be woken-up on open */
+ if (max3100s[i]->max3100_hw_suspend)
+ max3100s[i]->max3100_hw_suspend(1);
+ else {
+ tx = MAX3100_WC | MAX3100_SHDN;
+ max3100_sr(max3100s[i], tx, &rx);
+ }
}
mutex_unlock(&max3100s_lock);
return 0;
@@ -810,6 +957,9 @@ static int __devexit max3100_remove(struct spi_device *spi)
}
pr_debug("removing max3100 driver\n");
uart_unregister_driver(&max3100_uart_driver);
+#ifdef CONFIG_SERIAL_MAX3100_CONSOLE
+ unregister_console(&max3100_console);
+#endif
mutex_unlock(&max3100s_lock);
return 0;
--
1.5.6.5
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