[PATCH v4 04/11] pwm: imx: Rewrite imx_pwm_*_v1 code to facilitate switch to atomic pwm operation

Lukasz Majewski
2017-01-04T23:37:44Z

From: Lukasz Majewski <l.majewski@majess.pl>

The code has been rewritten to remove "generic" calls to
imx_pwm_{enable|disable|config}.

Such approach would facilitate switch to atomic PWM (a.k.a ->apply())
implementation.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
---
Changes for v4:
- None

[Minor code adjustment according to Stefan Agner comment]

Changes for v3:
- Remove ipg clock

Changes for v2:
- Add missing clock unprepare for clk_ipg
- Enable peripheral PWM clock (clk_per)
---
drivers/pwm/pwm-imx.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 0fa480d..11e3f3e 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -90,19 +90,34 @@ static int imx_pwm_config_v1(struct pwm_chip *chip,
return 0;
}

-static void imx_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+static int imx_pwm_enable_v1(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct imx_chip *imx = to_imx_chip(chip);
+ int ret;
u32 val;

+ ret = clk_prepare_enable(imx->clk_per);
+ if (ret)
+ return ret;
+
val = readl(imx->mmio_base + MX1_PWMC);
+ val |= MX1_PWMC_EN;
+ writel(val, imx->mmio_base + MX1_PWMC);

- if (enable)
- val |= MX1_PWMC_EN;
- else
- val &= ~MX1_PWMC_EN;
+ return 0;
+}
+
+static void imx_pwm_disable_v1(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct imx_chip *imx = to_imx_chip(chip);
+ u32 val;
+
+ val = readl(imx->mmio_base + MX1_PWMC);
+ val &= ~MX1_PWMC_EN;

writel(val, imx->mmio_base + MX1_PWMC);
+
+ clk_disable_unprepare(imx->clk_per);
}

static int imx_pwm_config_v2(struct pwm_chip *chip,
@@ -240,9 +255,9 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
}

static struct pwm_ops imx_pwm_ops_v1 = {
- .enable = imx_pwm_enable,
- .disable = imx_pwm_disable,
- .config = imx_pwm_config,
+ .enable = imx_pwm_enable_v1,
+ .disable = imx_pwm_disable_v1,
+ .config = imx_pwm_config_v1,
.owner = THIS_MODULE,
};

@@ -261,8 +276,6 @@ struct imx_pwm_data {
};

static struct imx_pwm_data imx_pwm_data_v1 = {
- .config = imx_pwm_config_v1,
- .set_enable = imx_pwm_set_enable_v1,
.pwm_ops = &imx_pwm_ops_v1,
};

--
2.1.4