[PATCH v2 06/10] pwm: imx: Provide atomic PWM support for i.MX PWMv2

[Lukasz Majewski]

This commit provides apply() callback implementation for i.MX's PWMv2.

Suggested-by: Stefan Agner 
Suggested-by: Boris Brezillon 
Signed-off-by: Lukasz Majewski 
Reviewed-by: Boris Brezillon 
---
Changes for v2:
- None
---
 drivers/pwm/pwm-imx.c | 76 +++
 1 file changed, 76 insertions(+)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index f7c7534..6b7d2f1 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -174,6 +174,81 @@ static void imx_pwm_wait_fifo_slot(struct pwm_chip *chip,
}
 }
 
+static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
+   struct pwm_state *state)
+{
+   unsigned long period_cycles, duty_cycles, prescale;
+   struct imx_chip *imx = to_imx_chip(chip);
+   struct pwm_state cstate;
+   unsigned long long c;
+   u32 cr = 0;
+   int ret;
+
+   ret = clk_prepare_enable(imx->clk_ipg);
+   if (ret)
+   return ret;
+
+   pwm_get_state(pwm, );
+
+   c = clk_get_rate(imx->clk_per);
+   c *= state->period;
+
+   do_div(c, 10);
+   period_cycles = c;
+
+   prescale = period_cycles / 0x1 + 1;
+
+   period_cycles /= prescale;
+   c = (unsigned long long)period_cycles * state->duty_cycle;
+   do_div(c, state->period);
+   duty_cycles = c;
+
+   /*
+* according to imx pwm RM, the real period value should be
+* PERIOD value in PWMPR plus 2.
+*/
+   if (period_cycles > 2)
+   period_cycles -= 2;
+   else
+   period_cycles = 0;
+
+   /* Enable the clock if the PWM is being enabled. */
+   if (state->enabled && !cstate.enabled) {
+   ret = clk_prepare_enable(imx->clk_per);
+   if (ret)
+   return ret;
+   }
+
+   /*
+* Wait for a free FIFO slot if the PWM is already enabled, and flush
+* the FIFO if the PWM was disabled and is about to be enabled.
+*/
+   if (cstate.enabled)
+   imx_pwm_wait_fifo_slot(chip, pwm);
+   else if (state->enabled)
+   imx_pwm_sw_reset(chip);
+
+   writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
+   writel(period_cycles, imx->mmio_base + MX3_PWMPR);
+
+   cr |= MX3_PWMCR_PRESCALER(prescale) |
+ MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+ MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH;
+
+   if (state->enabled)
+   cr |= MX3_PWMCR_EN;
+
+   writel(cr, imx->mmio_base + MX3_PWMCR);
+
+   /* Disable the clock if the PWM is being disabled. */
+   if (!state->enabled && cstate.enabled)
+   clk_disable_unprepare(imx->clk_per);
+
+   clk_disable_unprepare(imx->clk_ipg);
+
+   return 0;
+}
+
 static int imx_pwm_config_v2(struct pwm_chip *chip,
struct pwm_device *pwm, int duty_ns, int period_ns)
 {
@@ -297,6 +372,7 @@ static struct pwm_ops imx_pwm_ops_v2 = {
.enable = imx_pwm_enable,
.disable = imx_pwm_disable,
.config = imx_pwm_config,
+   .apply = imx_pwm_apply_v2,
.owner = THIS_MODULE,
 };
 
-- 
2.1.4

[PATCH v2 06/10] pwm: imx: Provide atomic PWM support for i.MX PWMv2

[Lukasz Majewski]

This commit provides apply() callback implementation for i.MX's PWMv2.

Suggested-by: Stefan Agner 
Suggested-by: Boris Brezillon 
Signed-off-by: Lukasz Majewski 
Reviewed-by: Boris Brezillon 
---
Changes for v2:
- None
---
 drivers/pwm/pwm-imx.c | 76 +++
 1 file changed, 76 insertions(+)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index f7c7534..6b7d2f1 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -174,6 +174,81 @@ static void imx_pwm_wait_fifo_slot(struct pwm_chip *chip,
}
 }
 
+static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
+   struct pwm_state *state)
+{
+   unsigned long period_cycles, duty_cycles, prescale;
+   struct imx_chip *imx = to_imx_chip(chip);
+   struct pwm_state cstate;
+   unsigned long long c;
+   u32 cr = 0;
+   int ret;
+
+   ret = clk_prepare_enable(imx->clk_ipg);
+   if (ret)
+   return ret;
+
+   pwm_get_state(pwm, );
+
+   c = clk_get_rate(imx->clk_per);
+   c *= state->period;
+
+   do_div(c, 10);
+   period_cycles = c;
+
+   prescale = period_cycles / 0x1 + 1;
+
+   period_cycles /= prescale;
+   c = (unsigned long long)period_cycles * state->duty_cycle;
+   do_div(c, state->period);
+   duty_cycles = c;
+
+   /*
+* according to imx pwm RM, the real period value should be
+* PERIOD value in PWMPR plus 2.
+*/
+   if (period_cycles > 2)
+   period_cycles -= 2;
+   else
+   period_cycles = 0;
+
+   /* Enable the clock if the PWM is being enabled. */
+   if (state->enabled && !cstate.enabled) {
+   ret = clk_prepare_enable(imx->clk_per);
+   if (ret)
+   return ret;
+   }
+
+   /*
+* Wait for a free FIFO slot if the PWM is already enabled, and flush
+* the FIFO if the PWM was disabled and is about to be enabled.
+*/
+   if (cstate.enabled)
+   imx_pwm_wait_fifo_slot(chip, pwm);
+   else if (state->enabled)
+   imx_pwm_sw_reset(chip);
+
+   writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
+   writel(period_cycles, imx->mmio_base + MX3_PWMPR);
+
+   cr |= MX3_PWMCR_PRESCALER(prescale) |
+ MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+ MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH;
+
+   if (state->enabled)
+   cr |= MX3_PWMCR_EN;
+
+   writel(cr, imx->mmio_base + MX3_PWMCR);
+
+   /* Disable the clock if the PWM is being disabled. */
+   if (!state->enabled && cstate.enabled)
+   clk_disable_unprepare(imx->clk_per);
+
+   clk_disable_unprepare(imx->clk_ipg);
+
+   return 0;
+}
+
 static int imx_pwm_config_v2(struct pwm_chip *chip,
struct pwm_device *pwm, int duty_ns, int period_ns)
 {
@@ -297,6 +372,7 @@ static struct pwm_ops imx_pwm_ops_v2 = {
.enable = imx_pwm_enable,
.disable = imx_pwm_disable,
.config = imx_pwm_config,
+   .apply = imx_pwm_apply_v2,
.owner = THIS_MODULE,
 };
 
-- 
2.1.4