diff options
| -rw-r--r-- | drivers/serial/samsung.c | 96 | ||||
| -rw-r--r-- | drivers/serial/samsung.h | 6 |
2 files changed, 102 insertions, 0 deletions
diff --git a/drivers/serial/samsung.c b/drivers/serial/samsung.c index 1e219d3d0352..ebeda832c8a3 100644 --- a/drivers/serial/samsung.c +++ b/drivers/serial/samsung.c @@ -42,6 +42,7 @@ #include <linux/serial.h> #include <linux/delay.h> #include <linux/clk.h> +#include <linux/cpufreq.h> #include <asm/irq.h> @@ -452,6 +453,8 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, { struct s3c24xx_uart_port *ourport = to_ourport(port); + ourport->pm_level = level; + switch (level) { case 3: if (!IS_ERR(ourport->baudclk) && ourport->baudclk != NULL) @@ -661,6 +664,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, ourport->clksrc = clksrc; ourport->baudclk = clk; + ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0; } switch (termios->c_cflag & CSIZE) { @@ -890,6 +894,93 @@ static inline int s3c24xx_serial_resetport(struct uart_port *port, return (info->reset_port)(port, cfg); } + +#ifdef CONFIG_CPU_FREQ + +static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb, + unsigned long val, void *data) +{ + struct s3c24xx_uart_port *port; + struct uart_port *uport; + + port = container_of(nb, struct s3c24xx_uart_port, freq_transition); + uport = &port->port; + + /* check to see if port is enabled */ + + if (port->pm_level != 0) + return 0; + + /* try and work out if the baudrate is changing, we can detect + * a change in rate, but we do not have support for detecting + * a disturbance in the clock-rate over the change. + */ + + if (IS_ERR(port->clk)) + goto exit; + + if (port->baudclk_rate == clk_get_rate(port->clk)) + goto exit; + + if (val == CPUFREQ_PRECHANGE) { + /* we should really shut the port down whilst the + * frequency change is in progress. */ + + } else if (val == CPUFREQ_POSTCHANGE) { + struct ktermios *termios; + struct tty_struct *tty; + + if (uport->info == NULL) { + printk(KERN_WARNING "%s: info NULL\n", __func__); + goto exit; + } + + tty = uport->info->port.tty; + + if (tty == NULL) { + printk(KERN_WARNING "%s: tty is NULL\n", __func__); + goto exit; + } + + termios = tty->termios; + + if (termios == NULL) { + printk(KERN_WARNING "%s: no termios?\n", __func__); + goto exit; + } + + s3c24xx_serial_set_termios(uport, termios, NULL); + } + + exit: + return 0; +} + +static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port) +{ + port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition; + + return cpufreq_register_notifier(&port->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} + +static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port) +{ + cpufreq_unregister_notifier(&port->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} + +#else +static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port) +{ + return 0; +} + +static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port) +{ +} +#endif + /* s3c24xx_serial_init_port * * initialise a single serial port from the platform device given @@ -1002,6 +1093,10 @@ int s3c24xx_serial_probe(struct platform_device *dev, if (ret < 0) printk(KERN_ERR "%s: failed to add clksrc attr.\n", __func__); + ret = s3c24xx_serial_cpufreq_register(ourport); + if (ret < 0) + dev_err(&dev->dev, "failed to add cpufreq notifier\n"); + return 0; probe_err: @@ -1015,6 +1110,7 @@ int s3c24xx_serial_remove(struct platform_device *dev) struct uart_port *port = s3c24xx_dev_to_port(&dev->dev); if (port) { + s3c24xx_serial_cpufreq_deregister(to_ourport(port)); device_remove_file(&dev->dev, &dev_attr_clock_source); uart_remove_one_port(&s3c24xx_uart_drv, port); } diff --git a/drivers/serial/samsung.h b/drivers/serial/samsung.h index 5c92ebbe7d9e..be263423205d 100644 --- a/drivers/serial/samsung.h +++ b/drivers/serial/samsung.h @@ -33,12 +33,18 @@ struct s3c24xx_uart_info { struct s3c24xx_uart_port { unsigned char rx_claimed; unsigned char tx_claimed; + unsigned int pm_level; + unsigned long baudclk_rate; struct s3c24xx_uart_info *info; struct s3c24xx_uart_clksrc *clksrc; struct clk *clk; struct clk *baudclk; struct uart_port port; + +#ifdef CONFIG_CPU_FREQ + struct notifier_block freq_transition; +#endif }; /* conversion functions */ |