2 files changed, 55 insertions, 38 deletions

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 9e147f3d7291..310ee555fade 100644
--- 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 9d5f69b2b57c..57a0cd46b847 100644
--- 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;
 };