[PATCH 0/4] add support for the new SAM9X60's PWM controller

[PATCH 0/4] add support for the new SAM9X60's PWM controller

[Claudiu.Beznea]

From: Claudiu Beznea <claudiu.beznea@microchip.com>

This series adds support for PWM controller of the new SAM9X60. The difference
b/w this one and the provious AT91SAM9X5 is the counter size (32 bits compared
with 16 bits on the previous version) thus, allowing to generate signals with
bigger periods and duty cycles. This series, modifies the driver to take into
account per IP counter size by embedding this information into driver's data.

Claudiu Beznea (4):
  pwm: atmel: add struct atmel_pwm_data
  pwm: atmel: add support for controllers with 32 bit counters
  pwm: atmel: add support for SAM9X60's PWM controller
  pwm: atmel: add PWM binding for SAM9X60

 .../devicetree/bindings/pwm/atmel-pwm.txt          |   1 +
 drivers/pwm/pwm-atmel.c                            | 119 ++++++++++++++-------
 2 files changed, 81 insertions(+), 39 deletions(-)

-- 
2.7.4

[PATCH 1/4] pwm: atmel: add struct atmel_pwm_data

[Claudiu.Beznea]

From: Claudiu Beznea <claudiu.beznea@microchip.com>

Add struct atmel_pwm_data to embed different per controller information. At
this stage, embed a member of type struct atmel_pwm_registers in it.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/pwm/pwm-atmel.c | 64 +++++++++++++++++++++++++++----------------------
 1 file changed, 36 insertions(+), 28 deletions(-)

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 530d7dc5f1b5..7e86a5266eb6 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -65,11 +65,15 @@ struct atmel_pwm_registers {
 	u8 duty_upd;
 };
 
+struct atmel_pwm_data {
+	struct atmel_pwm_registers regs;
+};
+
 struct atmel_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
 	void __iomem *base;
-	const struct atmel_pwm_registers *regs;
+	const struct atmel_pwm_data *data;
 
 	unsigned int updated_pwms;
 	/* ISR is cleared when read, ensure only one thread does that */
@@ -150,15 +154,15 @@ static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
 	u32 val;
 
-	if (atmel_pwm->regs->duty_upd ==
-	    atmel_pwm->regs->period_upd) {
+	if (atmel_pwm->data->regs.duty_upd ==
+	    atmel_pwm->data->regs.period_upd) {
 		val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
 		val &= ~PWM_CMR_UPD_CDTY;
 		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
 	}
 
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
-			    atmel_pwm->regs->duty_upd, cdty);
+			    atmel_pwm->data->regs.duty_upd, cdty);
 }
 
 static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
@@ -168,9 +172,9 @@ static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
 
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
-			    atmel_pwm->regs->duty, cdty);
+			    atmel_pwm->data->regs.duty, cdty);
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
-			    atmel_pwm->regs->period, cprd);
+			    atmel_pwm->data->regs.period, cprd);
 }
 
 static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -225,7 +229,7 @@ static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 		    cstate.polarity == state->polarity &&
 		    cstate.period == state->period) {
 			cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
-						  atmel_pwm->regs->period);
+						  atmel_pwm->data->regs.period);
 			atmel_pwm_calculate_cdty(state, cprd, &cdty);
 			atmel_pwm_update_cdty(chip, pwm, cdty);
 			return 0;
@@ -277,27 +281,31 @@ static const struct pwm_ops atmel_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
-static const struct atmel_pwm_registers atmel_pwm_regs_v1 = {
-	.period		= PWMV1_CPRD,
-	.period_upd	= PWMV1_CUPD,
-	.duty		= PWMV1_CDTY,
-	.duty_upd	= PWMV1_CUPD,
+static const struct atmel_pwm_data atmel_pwm_data_v1 = {
+	.regs = {
+		.period		= PWMV1_CPRD,
+		.period_upd	= PWMV1_CUPD,
+		.duty		= PWMV1_CDTY,
+		.duty_upd	= PWMV1_CUPD,
+	},
 };
 
-static const struct atmel_pwm_registers atmel_pwm_regs_v2 = {
-	.period		= PWMV2_CPRD,
-	.period_upd	= PWMV2_CPRDUPD,
-	.duty		= PWMV2_CDTY,
-	.duty_upd	= PWMV2_CDTYUPD,
+static const struct atmel_pwm_data atmel_pwm_data_v2 = {
+	.regs = {
+		.period		= PWMV2_CPRD,
+		.period_upd	= PWMV2_CPRDUPD,
+		.duty		= PWMV2_CDTY,
+		.duty_upd	= PWMV2_CDTYUPD,
+	},
 };
 
 static const struct platform_device_id atmel_pwm_devtypes[] = {
 	{
 		.name = "at91sam9rl-pwm",
-		.driver_data = (kernel_ulong_t)&atmel_pwm_regs_v1,
+		.driver_data = (kernel_ulong_t)&atmel_pwm_data_v1,
 	}, {
 		.name = "sama5d3-pwm",
-		.driver_data = (kernel_ulong_t)&atmel_pwm_regs_v2,
+		.driver_data = (kernel_ulong_t)&atmel_pwm_data_v2,
 	}, {
 		/* sentinel */
 	},
@@ -307,20 +315,20 @@ MODULE_DEVICE_TABLE(platform, atmel_pwm_devtypes);
 static const struct of_device_id atmel_pwm_dt_ids[] = {
 	{
 		.compatible = "atmel,at91sam9rl-pwm",
-		.data = &atmel_pwm_regs_v1,
+		.data = &atmel_pwm_data_v1,
 	}, {
 		.compatible = "atmel,sama5d3-pwm",
-		.data = &atmel_pwm_regs_v2,
+		.data = &atmel_pwm_data_v2,
 	}, {
 		.compatible = "atmel,sama5d2-pwm",
-		.data = &atmel_pwm_regs_v2,
+		.data = &atmel_pwm_data_v2,
 	}, {
 		/* sentinel */
 	},
 };
 MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids);
 
-static inline const struct atmel_pwm_registers *
+static inline const struct atmel_pwm_data *
 atmel_pwm_get_driver_data(struct platform_device *pdev)
 {
 	const struct platform_device_id *id;
@@ -330,18 +338,18 @@ atmel_pwm_get_driver_data(struct platform_device *pdev)
 
 	id = platform_get_device_id(pdev);
 
-	return (struct atmel_pwm_registers *)id->driver_data;
+	return (struct atmel_pwm_data *)id->driver_data;
 }
 
 static int atmel_pwm_probe(struct platform_device *pdev)
 {
-	const struct atmel_pwm_registers *regs;
+	const struct atmel_pwm_data *data;
 	struct atmel_pwm_chip *atmel_pwm;
 	struct resource *res;
 	int ret;
 
-	regs = atmel_pwm_get_driver_data(pdev);
-	if (!regs)
+	data = atmel_pwm_get_driver_data(pdev);
+	if (!data)
 		return -ENODEV;
 
 	atmel_pwm = devm_kzalloc(&pdev->dev, sizeof(*atmel_pwm), GFP_KERNEL);
@@ -373,7 +381,7 @@ static int atmel_pwm_probe(struct platform_device *pdev)
 
 	atmel_pwm->chip.base = -1;
 	atmel_pwm->chip.npwm = 4;
-	atmel_pwm->regs = regs;
+	atmel_pwm->data = data;
 	atmel_pwm->updated_pwms = 0;
 	mutex_init(&atmel_pwm->isr_lock);
 
-- 
2.7.4

[PATCH 2/4] pwm: atmel: add support for controllers with 32 bit counters

[Claudiu.Beznea]

From: Claudiu Beznea <claudiu.beznea@microchip.com>

New SAM9X60's PWM controller use 32 bits counters thus it could generate
signals with higher period and duty cycles. Update the current driver
to work with old controller (that uses 16 bits counters) and with the
new SAM9X60's controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/pwm/pwm-atmel.c | 38 +++++++++++++++++++++++++++-----------
 1 file changed, 27 insertions(+), 11 deletions(-)

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 7e86a5266eb6..44f4a1c9f60b 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -48,15 +48,15 @@
 #define PWMV2_CPRD		0x0C
 #define PWMV2_CPRDUPD		0x10
 
-/*
- * Max value for duty and period
- *
- * Although the duty and period register is 32 bit,
- * however only the LSB 16 bits are significant.
- */
-#define PWM_MAX_DTY		0xFFFF
-#define PWM_MAX_PRD		0xFFFF
-#define PRD_MAX_PRES		10
+/* Max values for period and prescaler */
+
+/* Only the LSB 16 bits are significant. */
+#define PWM_MAXV1_PRD		0xFFFF
+
+/* All 32 bits are significant. */
+#define PWM_MAXV2_PRD		0xFFFFFFFF
+
+#define PRD_MAXV1_PRES		10
 
 struct atmel_pwm_registers {
 	u8 period;
@@ -65,8 +65,14 @@ struct atmel_pwm_registers {
 	u8 duty_upd;
 };
 
+struct atmel_pwm_config {
+	u32 max_period;
+	u32 max_pres;
+};
+
 struct atmel_pwm_data {
 	struct atmel_pwm_registers regs;
+	struct atmel_pwm_config cfg;
 };
 
 struct atmel_pwm_chip {
@@ -125,10 +131,10 @@ static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip,
 	cycles *= clk_get_rate(atmel_pwm->clk);
 	do_div(cycles, NSEC_PER_SEC);
 
-	for (*pres = 0; cycles > PWM_MAX_PRD; cycles >>= 1)
+	for (*pres = 0; cycles > atmel_pwm->data->cfg.max_period; cycles >>= 1)
 		(*pres)++;
 
-	if (*pres > PRD_MAX_PRES) {
+	if (*pres > atmel_pwm->data->cfg.max_pres) {
 		dev_err(chip->dev, "pres exceeds the maximum value\n");
 		return -EINVAL;
 	}
@@ -288,6 +294,11 @@ static const struct atmel_pwm_data atmel_pwm_data_v1 = {
 		.duty		= PWMV1_CDTY,
 		.duty_upd	= PWMV1_CUPD,
 	},
+	.cfg = {
+		/* 16 bits to keep period and duty. */
+		.max_period	= PWM_MAXV1_PRD,
+		.max_pres	= PRD_MAXV1_PRES,
+	},
 };
 
 static const struct atmel_pwm_data atmel_pwm_data_v2 = {
@@ -297,6 +308,11 @@ static const struct atmel_pwm_data atmel_pwm_data_v2 = {
 		.duty		= PWMV2_CDTY,
 		.duty_upd	= PWMV2_CDTYUPD,
 	},
+	.cfg = {
+		/* 16 bits to keep period and duty. */
+		.max_period	= PWM_MAXV1_PRD,
+		.max_pres	= PRD_MAXV1_PRES,
+	},
 };
 
 static const struct platform_device_id atmel_pwm_devtypes[] = {
-- 
2.7.4

[PATCH 3/4] pwm: atmel: add support for SAM9X60's PWM controller

[Claudiu.Beznea]

From: Claudiu Beznea <claudiu.beznea@microchip.com>

Add support for SAM9X60's PWM controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/pwm/pwm-atmel.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 44f4a1c9f60b..44a99ba60e11 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -315,6 +315,20 @@ static const struct atmel_pwm_data atmel_pwm_data_v2 = {
 	},
 };
 
+static const struct atmel_pwm_data atmel_pwm_data_v3 = {
+	.regs = {
+		.period		= PWMV1_CPRD,
+		.period_upd	= PWMV1_CUPD,
+		.duty		= PWMV1_CDTY,
+		.duty_upd	= PWMV1_CUPD,
+	},
+	.cfg = {
+		/* 32 bits to keep period and duty. */
+		.max_period	= PWM_MAXV2_PRD,
+		.max_pres	= PRD_MAXV1_PRES,
+	},
+};
+
 static const struct platform_device_id atmel_pwm_devtypes[] = {
 	{
 		.name = "at91sam9rl-pwm",
@@ -339,6 +353,9 @@ static const struct of_device_id atmel_pwm_dt_ids[] = {
 		.compatible = "atmel,sama5d2-pwm",
 		.data = &atmel_pwm_data_v2,
 	}, {
+		.compatible = "microchip,sam9x60-pwm",
+		.data = &atmel_pwm_data_v3,
+	}, {
 		/* sentinel */
 	},
 };
-- 
2.7.4

[PATCH 4/4] pwm: atmel: add PWM binding for SAM9X60

[Claudiu.Beznea]

From: Claudiu Beznea <claudiu.beznea@microchip.com>

Add PWM binding for SAM9X60 SoC.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 Documentation/devicetree/bindings/pwm/atmel-pwm.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/pwm/atmel-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-pwm.txt
index c8c831d7b0d1..591ecdd39c7b 100644
--- a/Documentation/devicetree/bindings/pwm/atmel-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/atmel-pwm.txt
@@ -5,6 +5,7 @@ Required properties:
     - "atmel,at91sam9rl-pwm"
     - "atmel,sama5d3-pwm"
     - "atmel,sama5d2-pwm"
+    - "microchip,sam9x60-pwm"
   - reg: physical base address and length of the controller's registers
   - #pwm-cells: Should be 3. See pwm.txt in this directory for a
     description of the cells format.
-- 
2.7.4

Re: [PATCH 4/4] pwm: atmel: add PWM binding for SAM9X60

[Rob Herring]

On Mon, 21 Jan 2019 12:31:01 +0000, <Claudiu.Beznea@microchip.com> wrote:
> From: Claudiu Beznea <claudiu.beznea@microchip.com>
> 
> Add PWM binding for SAM9X60 SoC.
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> ---
>  Documentation/devicetree/bindings/pwm/atmel-pwm.txt | 1 +
>  1 file changed, 1 insertion(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH 2/4] pwm: atmel: add support for controllers with 32 bit counters

[Uwe Kleine-König]

Hello Claudiu,

On Mon, Jan 21, 2019 at 12:30:53PM +0000, Claudiu.Beznea@microchip.com wrote:
> From: Claudiu Beznea <claudiu.beznea@microchip.com>
> 
> New SAM9X60's PWM controller use 32 bits counters thus it could generate
> signals with higher period and duty cycles. Update the current driver
> to work with old controller (that uses 16 bits counters) and with the
> new SAM9X60's controller.
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> ---
>  drivers/pwm/pwm-atmel.c | 38 +++++++++++++++++++++++++++-----------
>  1 file changed, 27 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
> index 7e86a5266eb6..44f4a1c9f60b 100644
> --- a/drivers/pwm/pwm-atmel.c
> +++ b/drivers/pwm/pwm-atmel.c
> @@ -48,15 +48,15 @@
>  #define PWMV2_CPRD		0x0C
>  #define PWMV2_CPRDUPD		0x10
>  
> -/*
> - * Max value for duty and period
> - *
> - * Although the duty and period register is 32 bit,
> - * however only the LSB 16 bits are significant.
> - */
> -#define PWM_MAX_DTY		0xFFFF
> -#define PWM_MAX_PRD		0xFFFF
> -#define PRD_MAX_PRES		10
> +/* Max values for period and prescaler */
> +
> +/* Only the LSB 16 bits are significant. */
> +#define PWM_MAXV1_PRD		0xFFFF
> +
> +/* All 32 bits are significant. */
> +#define PWM_MAXV2_PRD		0xFFFFFFFF

This symbol is unused, so I wonder if the patch really does what the
commit log promises.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

Re: [PATCH 2/4] pwm: atmel: add support for controllers with 32 bit counters

[Claudiu.Beznea]

On 19.02.2019 09:42, Uwe Kleine-König wrote:
> Hello Claudiu,
> 
> On Mon, Jan 21, 2019 at 12:30:53PM +0000, Claudiu.Beznea@microchip.com wrote:
>> From: Claudiu Beznea <claudiu.beznea@microchip.com>
>>
>> New SAM9X60's PWM controller use 32 bits counters thus it could generate
>> signals with higher period and duty cycles. Update the current driver
>> to work with old controller (that uses 16 bits counters) and with the
>> new SAM9X60's controller.
>>
>> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>> ---
>>  drivers/pwm/pwm-atmel.c | 38 +++++++++++++++++++++++++++-----------
>>  1 file changed, 27 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
>> index 7e86a5266eb6..44f4a1c9f60b 100644
>> --- a/drivers/pwm/pwm-atmel.c
>> +++ b/drivers/pwm/pwm-atmel.c
>> @@ -48,15 +48,15 @@
>>  #define PWMV2_CPRD		0x0C
>>  #define PWMV2_CPRDUPD		0x10
>>  
>> -/*
>> - * Max value for duty and period
>> - *
>> - * Although the duty and period register is 32 bit,
>> - * however only the LSB 16 bits are significant.
>> - */
>> -#define PWM_MAX_DTY		0xFFFF
>> -#define PWM_MAX_PRD		0xFFFF
>> -#define PRD_MAX_PRES		10
>> +/* Max values for period and prescaler */
>> +
>> +/* Only the LSB 16 bits are significant. */
>> +#define PWM_MAXV1_PRD		0xFFFF
>> +
>> +/* All 32 bits are significant. */
>> +#define PWM_MAXV2_PRD		0xFFFFFFFF
> 
> This symbol is unused, so I wonder if the patch really does what the
> commit log promises.

It is only of SAM9X60's PWM. Please check patch 3/4. Maybe I should have
been introduced it in there. If you consider it is better to be introduced
in patch 3/4 please let me know.

> 
> Best regards
> Uwe
> 

Re: [PATCH 2/4] pwm: atmel: add support for controllers with 32 bit counters

[Uwe Kleine-König]

On Tue, Feb 19, 2019 at 08:57:04AM +0000, Claudiu.Beznea@microchip.com wrote:
> 
> 
> On 19.02.2019 09:42, Uwe Kleine-König wrote:
> > Hello Claudiu,
> > 
> > On Mon, Jan 21, 2019 at 12:30:53PM +0000, Claudiu.Beznea@microchip.com wrote:
> >> From: Claudiu Beznea <claudiu.beznea@microchip.com>
> >>
> >> New SAM9X60's PWM controller use 32 bits counters thus it could generate
> >> signals with higher period and duty cycles. Update the current driver
> >> to work with old controller (that uses 16 bits counters) and with the
> >> new SAM9X60's controller.
> >>
> >> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> >> ---
> >>  drivers/pwm/pwm-atmel.c | 38 +++++++++++++++++++++++++++-----------
> >>  1 file changed, 27 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
> >> index 7e86a5266eb6..44f4a1c9f60b 100644
> >> --- a/drivers/pwm/pwm-atmel.c
> >> +++ b/drivers/pwm/pwm-atmel.c
> >> @@ -48,15 +48,15 @@
> >>  #define PWMV2_CPRD		0x0C
> >>  #define PWMV2_CPRDUPD		0x10
> >>  
> >> -/*
> >> - * Max value for duty and period
> >> - *
> >> - * Although the duty and period register is 32 bit,
> >> - * however only the LSB 16 bits are significant.
> >> - */
> >> -#define PWM_MAX_DTY		0xFFFF
> >> -#define PWM_MAX_PRD		0xFFFF
> >> -#define PRD_MAX_PRES		10
> >> +/* Max values for period and prescaler */
> >> +
> >> +/* Only the LSB 16 bits are significant. */
> >> +#define PWM_MAXV1_PRD		0xFFFF
> >> +
> >> +/* All 32 bits are significant. */
> >> +#define PWM_MAXV2_PRD		0xFFFFFFFF
> > 
> > This symbol is unused, so I wonder if the patch really does what the
> > commit log promises.
> 
> It is only of SAM9X60's PWM. Please check patch 3/4. Maybe I should have
> been introduced it in there. If you consider it is better to be introduced
> in patch 3/4 please let me know.

Yeah, I think cpp symbols should be introduced with their first user.
And then the commit log should read something like:

	New SAM9X60's PWM controller use 32 bits counters thus it could
	generate signals with higher period and duty cycles compared to
	the already supported implementations that only have 16 bit
	counters. Update the driver to handle counter width depending on
	compatible data. Semantically this is a no-op but it's used in
	the next patch to add support for SAM9X60.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |