[PATCH v2] clk: si5351: Allow user to define disabled state for every clock output
Mike Turquette
mturquette at linaro.org
Tue May 14 15:13:50 EDT 2013
Quoting Marek Belisko (2013-05-02 22:33:27)
> From: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
>
> 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 at streamunlimited.com>
> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
Taken into clk-next.
Thanks,
Mike
> ---
> Changes from v1->v2:
> Sebastian Hesselbarth send me updated version of patch which was based
> on v1. Resending with updates.
>
> .../devicetree/bindings/clock/silabs,si5351.txt | 5 ++
> drivers/clk/clk-si5351.c | 74 +++++++++++++++++++-
> drivers/clk/clk-si5351.h | 1 +
> include/linux/platform_data/si5351.h | 18 +++++
> 4 files changed, 95 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/clock/silabs,si5351.txt b/Documentation/devicetree/bindings/clock/silabs,si5351.txt
> index cc37465..66c75b2 100644
> --- a/Documentation/devicetree/bindings/clock/silabs,si5351.txt
> +++ b/Documentation/devicetree/bindings/clock/silabs,si5351.txt
> @@ -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==
>
> diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c
> index 8323c31..098f28b 100644
> --- a/drivers/clk/clk-si5351.c
> +++ b/drivers/clk/clk-si5351.c
> @@ -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 */
> diff --git a/drivers/clk/clk-si5351.h b/drivers/clk/clk-si5351.h
> index af41b50..c0dbf26 100644
> --- a/drivers/clk/clk-si5351.h
> +++ b/drivers/clk/clk-si5351.h
> @@ -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
> diff --git a/include/linux/platform_data/si5351.h b/include/linux/platform_data/si5351.h
> index 92dabca..5433439 100644
> --- a/include/linux/platform_data/si5351.h
> +++ b/include/linux/platform_data/si5351.h
> @@ -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;
> };
> --
> 1.7.9.5
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