serial: max310x: Migrate to CLK API

This patch removes "frequency" parameter from MAX310X platform_data
and uses CLK API for getting clock. Clock type (XTAL/OSC) is
determined by clk name.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 9e147f3d7291c2a332d4df6b943fc04118efded4..310ee555fade8893913b6384dbce2d37d5f24842 100644 (file)
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -17,6 +17,7 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/bitops.h>
+#include <linux/clk.h>
 #include <linux/serial_core.h>
 #include <linux/serial.h>
 #include <linux/tty.h>
@@ -291,6 +292,7 @@ struct max310x_port {
        struct max310x_devtype  *devtype;
        struct regmap           *regmap;
        struct mutex            mutex;
+       struct clk              *clk;
        struct max310x_pdata    *pdata;
        int                     gpio_used;
 #ifdef CONFIG_GPIOLIB
@@ -546,18 +548,19 @@ static int max310x_update_best_err(unsigned long f, long *besterr)
        return 1;
 }
 
-static int max310x_set_ref_clk(struct max310x_port *s)
+static int max310x_set_ref_clk(struct max310x_port *s, unsigned long freq,
+                              bool xtal)
 {
        unsigned int div, clksrc, pllcfg = 0;
        long besterr = -1;
-       unsigned long fdiv, fmul, bestfreq = s->pdata->frequency;
+       unsigned long fdiv, fmul, bestfreq = freq;
 
        /* First, update error without PLL */
-       max310x_update_best_err(s->pdata->frequency, &besterr);
+       max310x_update_best_err(freq, &besterr);
 
        /* Try all possible PLL dividers */
        for (div = 1; (div <= 63) && besterr; div++) {
-               fdiv = DIV_ROUND_CLOSEST(s->pdata->frequency, div);
+               fdiv = DIV_ROUND_CLOSEST(freq, div);
 
                /* Try multiplier 6 */
                fmul = fdiv * 6;
@@ -590,10 +593,7 @@ static int max310x_set_ref_clk(struct max310x_port *s)
        }
 
        /* Configure clock source */
-       if (s->pdata->driver_flags & MAX310X_EXT_CLK)
-               clksrc = MAX310X_CLKSRC_EXTCLK_BIT;
-       else
-               clksrc = MAX310X_CLKSRC_CRYST_BIT;
+       clksrc = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_BIT;
 
        /* Configure PLL */
        if (pllcfg) {
@@ -605,7 +605,7 @@ static int max310x_set_ref_clk(struct max310x_port *s)
        regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
 
        /* Wait for crystal */
-       if (pllcfg && !(s->pdata->driver_flags & MAX310X_EXT_CLK))
+       if (pllcfg && xtal)
                msleep(10);
 
        return (int)bestfreq;
@@ -1078,9 +1078,11 @@ static int max310x_gpio_direction_output(struct gpio_chip *chip,
 static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
                         struct regmap *regmap, int irq)
 {
-       struct max310x_port *s;
        struct max310x_pdata *pdata = dev_get_platdata(dev);
-       int i, ret, uartclk;
+       int i, ret, fmin, fmax, freq, uartclk;
+       struct clk *clk_osc, *clk_xtal;
+       struct max310x_port *s;
+       bool xtal = false;
 
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);
@@ -1098,14 +1100,35 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
                return -ENOMEM;
        }
 
-       /* Check input frequency */
-       if ((pdata->driver_flags & MAX310X_EXT_CLK) &&
-          ((pdata->frequency < 500000) || (pdata->frequency > 35000000)))
-               goto err_freq;
-       /* Check frequency for quartz */
-       if (!(pdata->driver_flags & MAX310X_EXT_CLK) &&
-          ((pdata->frequency < 1000000) || (pdata->frequency > 4000000)))
-               goto err_freq;
+       clk_osc = devm_clk_get(dev, "osc");
+       clk_xtal = devm_clk_get(dev, "xtal");
+       if (!IS_ERR(clk_osc)) {
+               s->clk = clk_osc;
+               fmin = 500000;
+               fmax = 35000000;
+       } else if (!IS_ERR(clk_xtal)) {
+               s->clk = clk_xtal;
+               fmin = 1000000;
+               fmax = 4000000;
+               xtal = true;
+       } else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
+                  PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
+               return -EPROBE_DEFER;
+       } else {
+               dev_err(dev, "Cannot get clock\n");
+               return -EINVAL;
+       }
+
+       ret = clk_prepare_enable(s->clk);
+       if (ret)
+               return ret;
+
+       freq = clk_get_rate(s->clk);
+       /* Check frequency limits */
+       if (freq < fmin || freq > fmax) {
+               ret = -ERANGE;
+               goto out_clk;
+       }
 
        s->pdata = pdata;
        s->regmap = regmap;
@@ -1117,7 +1140,7 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
        /* Check device to ensure we are talking to what we expect */
        ret = devtype->detect(dev);
        if (ret)
-               return ret;
+               goto out_clk;
 
        for (i = 0; i < devtype->nr; i++) {
                unsigned int offs = i << 5;
@@ -1139,7 +1162,7 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
                                   MAX310X_MODE1_AUTOSLEEP_BIT);
        }
 
-       uartclk = max310x_set_ref_clk(s);
+       uartclk = max310x_set_ref_clk(s, freq, xtal);
        dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
 
        /* Register UART driver */
@@ -1151,7 +1174,7 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
        ret = uart_register_driver(&s->uart);
        if (ret) {
                dev_err(dev, "Registering UART driver failed\n");
-               return ret;
+               goto out_clk;
        }
 
        for (i = 0; i < devtype->nr; i++) {
@@ -1208,19 +1231,19 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
        ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
                                        IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                        dev_name(dev), s);
-       if (ret) {
-               dev_err(dev, "Unable to reguest IRQ %i\n", irq);
+       if (!ret)
+               return 0;
+
+       dev_err(dev, "Unable to reguest IRQ %i\n", irq);
 #ifdef CONFIG_GPIOLIB
-               if (s->gpio_used)
-                       WARN_ON(gpiochip_remove(&s->gpio));
+       if (s->gpio_used)
+               WARN_ON(gpiochip_remove(&s->gpio));
 #endif
-       }
 
-       return ret;
+out_clk:
+       clk_disable_unprepare(s->clk);
 
-err_freq:
-       dev_err(dev, "Frequency parameter incorrect\n");
-       return -EINVAL;
+       return ret;
 }
 
 static int max310x_remove(struct device *dev)
@@ -1236,6 +1259,7 @@ static int max310x_remove(struct device *dev)
        }
 
        uart_unregister_driver(&s->uart);
+       clk_disable_unprepare(s->clk);
 
 #ifdef CONFIG_GPIOLIB
        if (s->gpio_used)

diff --git a/include/linux/platform_data/max310x.h b/include/linux/platform_data/max310x.h
index 9d5f69b2b57cfc39e407efd0480c2a4168c01060..57a0cd46b8476b4e859c13b851b54da42af22573 100644 (file)
--- a/include/linux/platform_data/max310x.h
+++ b/include/linux/platform_data/max310x.h
@@ -20,9 +20,7 @@
  * Example board initialization data:
  *
  * static struct max310x_pdata max3107_pdata = {
- *     .driver_flags   = MAX310X_EXT_CLK,
  *     .uart_flags[0]  = MAX310X_ECHO_SUPRESS | MAX310X_AUTO_DIR_CTRL,
- *     .frequency      = 3686400,
  *     .gpio_base      = -1,
  * };
  *
@@ -41,17 +39,12 @@
 
 /* MAX310X platform data structure */
 struct max310x_pdata {
-       /* Flags global to driver */
-       const u8                driver_flags;
-#define MAX310X_EXT_CLK                (0x00000001)    /* External clock enable */
        /* Flags global to UART port */
        const u8                uart_flags[MAX310X_MAX_UARTS];
 #define MAX310X_ECHO_SUPRESS   (0x00000002)    /* Enable echo supress */
 #define MAX310X_AUTO_DIR_CTRL  (0x00000004)    /* Enable Auto direction
                                                 * control (RS-485)
                                                 */
-       /* Frequency (extrenal clock or crystal) */
-       const int               frequency;
        /* GPIO base number (can be negative) */
        const int               gpio_base;
 };