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clk: si5351: Allow user to define disabled state for every clock output
authorSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Fri, 3 May 2013 05:33:27 +0000 (07:33 +0200)
committerMike Turquette <mturquette@linaro.org>
Wed, 29 May 2013 05:50:31 +0000 (22:50 -0700)
This patch adds platform data and DT bindings to allow to overwrite
the stored disabled state for each clock output.

Signed-off-by: Marek Belisko <marek.belisko@streamunlimited.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Documentation/devicetree/bindings/clock/silabs,si5351.txt
drivers/clk/clk-si5351.c
drivers/clk/clk-si5351.h
include/linux/platform_data/si5351.h

index cc37465..66c75b2 100644 (file)
@@ -44,6 +44,11 @@ Optional child node properties:
 - silabs,multisynth-source: source pll A(0) or B(1) of corresponding multisynth
   divider.
 - silabs,pll-master: boolean, multisynth can change pll frequency.
+- silabs,disable-state : clock output disable state, shall be
+  0 = clock output is driven LOW when disabled
+  1 = clock output is driven HIGH when disabled
+  2 = clock output is FLOATING (HIGH-Z) when disabled
+  3 = clock output is NEVER disabled
 
 ==Example==
 
index 8927284..efc6d5e 100644 (file)
@@ -851,6 +851,41 @@ static int _si5351_clkout_set_drive_strength(
        return 0;
 }
 
+static int _si5351_clkout_set_disable_state(
+       struct si5351_driver_data *drvdata, int num,
+       enum si5351_disable_state state)
+{
+       u8 reg = (num < 4) ? SI5351_CLK3_0_DISABLE_STATE :
+               SI5351_CLK7_4_DISABLE_STATE;
+       u8 shift = (num < 4) ? (2 * num) : (2 * (num-4));
+       u8 mask = SI5351_CLK_DISABLE_STATE_MASK << shift;
+       u8 val;
+
+       if (num > 8)
+               return -EINVAL;
+
+       switch (state) {
+       case SI5351_DISABLE_LOW:
+               val = SI5351_CLK_DISABLE_STATE_LOW;
+               break;
+       case SI5351_DISABLE_HIGH:
+               val = SI5351_CLK_DISABLE_STATE_HIGH;
+               break;
+       case SI5351_DISABLE_FLOATING:
+               val = SI5351_CLK_DISABLE_STATE_FLOAT;
+               break;
+       case SI5351_DISABLE_NEVER:
+               val = SI5351_CLK_DISABLE_STATE_NEVER;
+               break;
+       default:
+               return 0;
+       }
+
+       si5351_set_bits(drvdata, reg, mask, val << shift);
+
+       return 0;
+}
+
 static int si5351_clkout_prepare(struct clk_hw *hw)
 {
        struct si5351_hw_data *hwdata =
@@ -1225,6 +1260,33 @@ static int si5351_dt_parse(struct i2c_client *client)
                        }
                }
 
+               if (!of_property_read_u32(child, "silabs,disable-state",
+                                         &val)) {
+                       switch (val) {
+                       case 0:
+                               pdata->clkout[num].disable_state =
+                                       SI5351_DISABLE_LOW;
+                               break;
+                       case 1:
+                               pdata->clkout[num].disable_state =
+                                       SI5351_DISABLE_HIGH;
+                               break;
+                       case 2:
+                               pdata->clkout[num].disable_state =
+                                       SI5351_DISABLE_FLOATING;
+                               break;
+                       case 3:
+                               pdata->clkout[num].disable_state =
+                                       SI5351_DISABLE_NEVER;
+                               break;
+                       default:
+                               dev_err(&client->dev,
+                                       "invalid disable state %d for clkout %d\n",
+                                       val, num);
+                               return -EINVAL;
+                       }
+               }
+
                if (!of_property_read_u32(child, "clock-frequency", &val))
                        pdata->clkout[num].rate = val;
 
@@ -1281,9 +1343,6 @@ static int si5351_i2c_probe(struct i2c_client *client,
 
        /* Disable interrupts */
        si5351_reg_write(drvdata, SI5351_INTERRUPT_MASK, 0xf0);
-       /* Set disabled output drivers to drive low */
-       si5351_reg_write(drvdata, SI5351_CLK3_0_DISABLE_STATE, 0x00);
-       si5351_reg_write(drvdata, SI5351_CLK7_4_DISABLE_STATE, 0x00);
        /* Ensure pll select is on XTAL for Si5351A/B */
        if (drvdata->variant != SI5351_VARIANT_C)
                si5351_set_bits(drvdata, SI5351_PLL_INPUT_SOURCE,
@@ -1327,6 +1386,15 @@ static int si5351_i2c_probe(struct i2c_client *client,
                                n, pdata->clkout[n].drive);
                        return ret;
                }
+
+               ret = _si5351_clkout_set_disable_state(drvdata, n,
+                                               pdata->clkout[n].disable_state);
+               if (ret) {
+                       dev_err(&client->dev,
+                               "failed set disable state of clkout%d to %d\n",
+                               n, pdata->clkout[n].disable_state);
+                       return ret;
+               }
        }
 
        /* register xtal input clock gate */
index af41b50..c0dbf26 100644 (file)
@@ -81,6 +81,7 @@
 
 #define SI5351_CLK3_0_DISABLE_STATE            24
 #define SI5351_CLK7_4_DISABLE_STATE            25
+#define  SI5351_CLK_DISABLE_STATE_MASK         3
 #define  SI5351_CLK_DISABLE_STATE_LOW          0
 #define  SI5351_CLK_DISABLE_STATE_HIGH         1
 #define  SI5351_CLK_DISABLE_STATE_FLOAT                2
index 92dabca..5433439 100644 (file)
@@ -79,6 +79,23 @@ enum si5351_drive_strength {
 };
 
 /**
+ * enum si5351_disable_state - Si5351 clock output disable state
+ * @SI5351_DISABLE_DEFAULT: default, do not change eeprom config
+ * @SI5351_DISABLE_LOW: CLKx is set to a LOW state when disabled
+ * @SI5351_DISABLE_HIGH: CLKx is set to a HIGH state when disabled
+ * @SI5351_DISABLE_FLOATING: CLKx is set to a FLOATING state when
+ *                             disabled
+ * @SI5351_DISABLE_NEVER: CLKx is NEVER disabled
+ */
+enum si5351_disable_state {
+       SI5351_DISABLE_DEFAULT = 0,
+       SI5351_DISABLE_LOW,
+       SI5351_DISABLE_HIGH,
+       SI5351_DISABLE_FLOATING,
+       SI5351_DISABLE_NEVER,
+};
+
+/**
  * struct si5351_clkout_config - Si5351 clock output configuration
  * @clkout: clkout number
  * @multisynth_src: multisynth source clock
@@ -91,6 +108,7 @@ struct si5351_clkout_config {
        enum si5351_multisynth_src multisynth_src;
        enum si5351_clkout_src clkout_src;
        enum si5351_drive_strength drive;
+       enum si5351_disable_state disable_state;
        bool pll_master;
        unsigned long rate;
 };