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path: root/drivers/tty/serial/ar933x_uart.c
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Diffstat (limited to 'drivers/tty/serial/ar933x_uart.c')
-rw-r--r--drivers/tty/serial/ar933x_uart.c222
1 files changed, 158 insertions, 64 deletions
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
index e4f60e2b87f..acd03af7cd5 100644
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -17,6 +17,8 @@
#include <linux/sysrq.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
@@ -24,12 +26,20 @@
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/irq.h>
+#include <linux/clk.h>
+
+#include <asm/div64.h>
#include <asm/mach-ath79/ar933x_uart.h>
-#include <asm/mach-ath79/ar933x_uart_platform.h>
#define DRIVER_NAME "ar933x-uart"
+#define AR933X_UART_MAX_SCALE 0xff
+#define AR933X_UART_MAX_STEP 0xffff
+
+#define AR933X_UART_MIN_BAUD 300
+#define AR933X_UART_MAX_BAUD 3000000
+
#define AR933X_DUMMY_STATUS_RD 0x01
static struct uart_driver ar933x_uart_driver;
@@ -37,8 +47,16 @@ static struct uart_driver ar933x_uart_driver;
struct ar933x_uart_port {
struct uart_port port;
unsigned int ier; /* shadow Interrupt Enable Register */
+ unsigned int min_baud;
+ unsigned int max_baud;
+ struct clk *clk;
};
+static inline bool ar933x_uart_console_enabled(void)
+{
+ return config_enabled(CONFIG_SERIAL_AR933X_CONSOLE);
+}
+
static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
int offset)
{
@@ -162,6 +180,57 @@ static void ar933x_uart_enable_ms(struct uart_port *port)
{
}
+/*
+ * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
+ */
+static unsigned long ar933x_uart_get_baud(unsigned int clk,
+ unsigned int scale,
+ unsigned int step)
+{
+ u64 t;
+ u32 div;
+
+ div = (2 << 16) * (scale + 1);
+ t = clk;
+ t *= step;
+ t += (div / 2);
+ do_div(t, div);
+
+ return t;
+}
+
+static void ar933x_uart_get_scale_step(unsigned int clk,
+ unsigned int baud,
+ unsigned int *scale,
+ unsigned int *step)
+{
+ unsigned int tscale;
+ long min_diff;
+
+ *scale = 0;
+ *step = 0;
+
+ min_diff = baud;
+ for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
+ u64 tstep;
+ int diff;
+
+ tstep = baud * (tscale + 1);
+ tstep *= (2 << 16);
+ do_div(tstep, clk);
+
+ if (tstep > AR933X_UART_MAX_STEP)
+ break;
+
+ diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
+ if (diff < min_diff) {
+ min_diff = diff;
+ *scale = tscale;
+ *step = tstep;
+ }
+ }
+}
+
static void ar933x_uart_set_termios(struct uart_port *port,
struct ktermios *new,
struct ktermios *old)
@@ -169,7 +238,7 @@ static void ar933x_uart_set_termios(struct uart_port *port,
struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
unsigned int cs;
unsigned long flags;
- unsigned int baud, scale;
+ unsigned int baud, scale, step;
/* Only CS8 is supported */
new->c_cflag &= ~CSIZE;
@@ -191,8 +260,8 @@ static void ar933x_uart_set_termios(struct uart_port *port,
/* Mark/space parity is not supported */
new->c_cflag &= ~CMSPAR;
- baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
- scale = (port->uartclk / (16 * baud)) - 1;
+ baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
+ ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);
/*
* Ok, we're now changing the port state. Do it with
@@ -200,6 +269,10 @@ static void ar933x_uart_set_termios(struct uart_port *port,
*/
spin_lock_irqsave(&up->port.lock, flags);
+ /* disable the UART */
+ ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
+ AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);
+
/* Update the per-port timeout. */
uart_update_timeout(port, new->c_cflag, baud);
@@ -210,7 +283,7 @@ static void ar933x_uart_set_termios(struct uart_port *port,
up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD;
ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
- scale << AR933X_UART_CLOCK_SCALE_S | 8192);
+ scale << AR933X_UART_CLOCK_SCALE_S | step);
/* setup configuration register */
ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);
@@ -219,6 +292,11 @@ static void ar933x_uart_set_termios(struct uart_port *port,
ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
AR933X_UART_CS_HOST_INT_EN);
+ /* reenable the UART */
+ ar933x_uart_rmw(up, AR933X_UART_CS_REG,
+ AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
+ AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
+
spin_unlock_irqrestore(&up->port.lock, flags);
if (tty_termios_baud_rate(new))
@@ -227,10 +305,9 @@ static void ar933x_uart_set_termios(struct uart_port *port,
static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
{
- struct tty_struct *tty;
+ struct tty_port *port = &up->port.state->port;
int max_count = 256;
- tty = tty_port_tty_get(&up->port.state->port);
do {
unsigned int rdata;
unsigned char ch;
@@ -243,11 +320,6 @@ static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
ar933x_uart_write(up, AR933X_UART_DATA_REG,
AR933X_UART_DATA_RX_CSR);
- if (!tty) {
- /* discard the data if no tty available */
- continue;
- }
-
up->port.icount.rx++;
ch = rdata & AR933X_UART_DATA_TX_RX_MASK;
@@ -255,13 +327,12 @@ static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
continue;
if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
- tty_insert_flip_char(tty, ch, TTY_NORMAL);
+ tty_insert_flip_char(port, ch, TTY_NORMAL);
} while (max_count-- > 0);
- if (tty) {
- tty_flip_buffer_push(tty);
- tty_kref_put(tty);
- }
+ spin_unlock(&up->port.lock);
+ tty_flip_buffer_push(port);
+ spin_lock(&up->port.lock);
}
static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
@@ -401,6 +472,8 @@ static void ar933x_uart_config_port(struct uart_port *port, int flags)
static int ar933x_uart_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
+ struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
+
if (ser->type != PORT_UNKNOWN &&
ser->type != PORT_AR933X)
return -EINVAL;
@@ -408,7 +481,8 @@ static int ar933x_uart_verify_port(struct uart_port *port,
if (ser->irq < 0 || ser->irq >= NR_IRQS)
return -EINVAL;
- if (ser->baud_base < 28800)
+ if (ser->baud_base < up->min_baud ||
+ ser->baud_base > up->max_baud)
return -EINVAL;
return 0;
@@ -433,8 +507,6 @@ static struct uart_ops ar933x_uart_ops = {
.verify_port = ar933x_uart_verify_port,
};
-#ifdef CONFIG_SERIAL_AR933X_CONSOLE
-
static struct ar933x_uart_port *
ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];
@@ -533,122 +605,142 @@ static struct console ar933x_uart_console = {
static void ar933x_uart_add_console_port(struct ar933x_uart_port *up)
{
+ if (!ar933x_uart_console_enabled())
+ return;
+
ar933x_console_ports[up->port.line] = up;
}
-#define AR933X_SERIAL_CONSOLE (&ar933x_uart_console)
-
-#else
-
-static inline void ar933x_uart_add_console_port(struct ar933x_uart_port *up) {}
-
-#define AR933X_SERIAL_CONSOLE NULL
-
-#endif /* CONFIG_SERIAL_AR933X_CONSOLE */
-
static struct uart_driver ar933x_uart_driver = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = "ttyATH",
.nr = CONFIG_SERIAL_AR933X_NR_UARTS,
- .cons = AR933X_SERIAL_CONSOLE,
+ .cons = NULL, /* filled in runtime */
};
-static int __devinit ar933x_uart_probe(struct platform_device *pdev)
+static int ar933x_uart_probe(struct platform_device *pdev)
{
- struct ar933x_uart_platform_data *pdata;
struct ar933x_uart_port *up;
struct uart_port *port;
struct resource *mem_res;
struct resource *irq_res;
+ struct device_node *np;
+ unsigned int baud;
int id;
int ret;
- pdata = pdev->dev.platform_data;
- if (!pdata)
- return -EINVAL;
-
- id = pdev->id;
- if (id == -1)
- id = 0;
+ np = pdev->dev.of_node;
+ if (config_enabled(CONFIG_OF) && np) {
+ id = of_alias_get_id(np, "serial");
+ if (id < 0) {
+ dev_err(&pdev->dev, "unable to get alias id, err=%d\n",
+ id);
+ return id;
+ }
+ } else {
+ id = pdev->id;
+ if (id == -1)
+ id = 0;
+ }
if (id > CONFIG_SERIAL_AR933X_NR_UARTS)
return -EINVAL;
- mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!mem_res) {
- dev_err(&pdev->dev, "no MEM resource\n");
- return -EINVAL;
- }
-
irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!irq_res) {
dev_err(&pdev->dev, "no IRQ resource\n");
return -EINVAL;
}
- up = kzalloc(sizeof(struct ar933x_uart_port), GFP_KERNEL);
+ up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
+ GFP_KERNEL);
if (!up)
return -ENOMEM;
+ up->clk = devm_clk_get(&pdev->dev, "uart");
+ if (IS_ERR(up->clk)) {
+ dev_err(&pdev->dev, "unable to get UART clock\n");
+ return PTR_ERR(up->clk);
+ }
+
port = &up->port;
- port->mapbase = mem_res->start;
- port->membase = ioremap(mem_res->start, AR933X_UART_REGS_SIZE);
- if (!port->membase) {
- ret = -ENOMEM;
- goto err_free_up;
+ mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ port->membase = devm_ioremap_resource(&pdev->dev, mem_res);
+ if (IS_ERR(port->membase))
+ return PTR_ERR(port->membase);
+
+ ret = clk_prepare_enable(up->clk);
+ if (ret)
+ return ret;
+
+ port->uartclk = clk_get_rate(up->clk);
+ if (!port->uartclk) {
+ ret = -EINVAL;
+ goto err_disable_clk;
}
+ port->mapbase = mem_res->start;
port->line = id;
port->irq = irq_res->start;
port->dev = &pdev->dev;
port->type = PORT_AR933X;
port->iotype = UPIO_MEM32;
- port->uartclk = pdata->uartclk;
port->regshift = 2;
port->fifosize = AR933X_UART_FIFO_SIZE;
port->ops = &ar933x_uart_ops;
+ baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
+ up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
+
+ baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
+ up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
+
ar933x_uart_add_console_port(up);
ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
if (ret)
- goto err_unmap;
+ goto err_disable_clk;
platform_set_drvdata(pdev, up);
return 0;
-err_unmap:
- iounmap(up->port.membase);
-err_free_up:
- kfree(up);
+err_disable_clk:
+ clk_disable_unprepare(up->clk);
return ret;
}
-static int __devexit ar933x_uart_remove(struct platform_device *pdev)
+static int ar933x_uart_remove(struct platform_device *pdev)
{
struct ar933x_uart_port *up;
up = platform_get_drvdata(pdev);
- platform_set_drvdata(pdev, NULL);
if (up) {
uart_remove_one_port(&ar933x_uart_driver, &up->port);
- iounmap(up->port.membase);
- kfree(up);
+ clk_disable_unprepare(up->clk);
}
return 0;
}
+#ifdef CONFIG_OF
+static const struct of_device_id ar933x_uart_of_ids[] = {
+ { .compatible = "qca,ar9330-uart" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ar933x_uart_of_ids);
+#endif
+
static struct platform_driver ar933x_uart_platform_driver = {
.probe = ar933x_uart_probe,
- .remove = __devexit_p(ar933x_uart_remove),
+ .remove = ar933x_uart_remove,
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(ar933x_uart_of_ids),
},
};
@@ -656,7 +748,9 @@ static int __init ar933x_uart_init(void)
{
int ret;
- ar933x_uart_driver.nr = CONFIG_SERIAL_AR933X_NR_UARTS;
+ if (ar933x_uart_console_enabled())
+ ar933x_uart_driver.cons = &ar933x_uart_console;
+
ret = uart_register_driver(&ar933x_uart_driver);
if (ret)
goto err_out;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 12:10:49 +0000