[PATCH v2] pwm i.MX: add devicetree support

STALE5078d

14 messages, 3 authors, 2012-09-06 · open the first message on its own page

[PATCH v2] pwm i.MX: add devicetree support

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:35:54

Changes since v1:

- Add devicetree binding documentation
- Merge 5/9 and 9/9
- fix #pwm-cells (must be 2 instead of 3)
- fix wrong name in MODULE_DEVICE_TABLE
- drop platform based probing while introducing devicetree based probe

----------------------------------------------------------------
Philipp Zabel (2):
      pwm i.MX: add devicetree support
      pwm i.MX: fix clock lookup

Sascha Hauer (6):
      pwm i.MX: factor out SoC specific functions
      pwm i.MX: remove unnecessary if in pwm_[en|dis]able
      pwm i.MX: add functions to enable/disable pwm.
      pwm i.MX: Use module_platform_driver
      pwm i.MX: use per clock unconditionally
      ARM i.MX53: Add pwm support

 Documentation/devicetree/bindings/pwm/imx-pwm.txt |   17 ++
 arch/arm/boot/dts/imx53.dtsi                      |   14 ++
 arch/arm/mach-imx/clk-imx51-imx53.c               |    4 +
 drivers/pwm/pwm-imx.c                             |  275 ++++++++++++++-------
 4 files changed, 214 insertions(+), 96 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pwm/imx-pwm.txt

[PATCH 4/8] pwm i.MX: Use module_platform_driver

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:35:40

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/pwm-imx.c |   12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 3fc4ae8..a689144 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -270,17 +270,7 @@ static struct platform_driver imx_pwm_driver = {
 	.remove		= __devexit_p(imx_pwm_remove),
 };
 
-static int __init imx_pwm_init(void)
-{
-	return platform_driver_register(&imx_pwm_driver);
-}
-arch_initcall(imx_pwm_init);
-
-static void __exit imx_pwm_exit(void)
-{
-	platform_driver_unregister(&imx_pwm_driver);
-}
-module_exit(imx_pwm_exit);
+module_platform_driver(imx_pwm_driver);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
-- 
1.7.10.4

[PATCH 7/8] pwm i.MX: fix clock lookup

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:35:42

From: Philipp Zabel <p.zabel@pengutronix.de>

The i.MX pwm core has two clocks: The ipg clock and the ipg highfreq
(peripheral) clock. The ipg clock has to be enabled for this hardware
to work. The actual pwm output can either be driven by the ipg clock
or the ipg highfreq. The ipg highfreq has the advantage that it runs
even when the SoC is in low power modes.
This patch requests both clocks and enables the ipg clock for accessing
registers and the peripheral clock to actually turn on the pwm.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/pwm-imx.c |   33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index b234288..5b03ace 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -40,7 +40,8 @@
 #define MX3_PWMCR_EN              (1 << 0)
 
 struct imx_chip {
-	struct clk	*clk;
+	struct clk	*clk_per;
+	struct clk	*clk_ipg;
 
 	int		enabled;
 	void __iomem	*mmio_base;
@@ -105,7 +106,7 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
 	unsigned long period_cycles, duty_cycles, prescale;
 	u32 cr;
 
-	c = clk_get_rate(imx->clk);
+	c = clk_get_rate(imx->clk_per);
 	c = c * period_ns;
 	do_div(c, 1000000000);
 	period_cycles = c;
@@ -160,8 +161,15 @@ static int imx_pwm_config(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
+	int ret;
 
-	return imx->config(chip, pwm, duty_ns, period_ns);
+	clk_prepare_enable(imx->clk_ipg);
+
+	ret = imx->config(chip, pwm, duty_ns, period_ns);
+
+	clk_disable_unprepare(imx->clk_ipg);
+
+	return ret;
 }
 
 static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -169,7 +177,7 @@ static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	struct imx_chip *imx = to_imx_chip(chip);
 	int rc;
 
-	rc = clk_prepare_enable(imx->clk);
+	rc = clk_prepare_enable(imx->clk_per);
 	if (rc)
 		return rc;
 
@@ -186,7 +194,7 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	imx->set_enable(chip, false);
 
-	clk_disable_unprepare(imx->clk);
+	clk_disable_unprepare(imx->clk_per);
 	imx->enabled = 0;
 }
 
@@ -238,10 +246,19 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	imx->clk = devm_clk_get(&pdev->dev, "pwm");
+	imx->clk_per = devm_clk_get(&pdev->dev, "per");
+	if (IS_ERR(imx->clk_per)) {
+		dev_err(&pdev->dev, "getting per clock failed with %ld\n",
+				PTR_ERR(imx->clk_per));
+		return PTR_ERR(imx->clk_per);
+	}
 
-	if (IS_ERR(imx->clk))
-		return PTR_ERR(imx->clk);
+	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(imx->clk_ipg)) {
+		dev_err(&pdev->dev, "getting ipg clock failed with %ld\n",
+				PTR_ERR(imx->clk_ipg));
+		return PTR_ERR(imx->clk_ipg);
+	}
 
 	imx->chip.ops = &imx_pwm_ops;
 	imx->chip.dev = &pdev->dev;
-- 
1.7.10.4

Re: [PATCH 7/8] pwm i.MX: fix clock lookup

From: Benoît Thébaudeau <hidden>
Date: 2012-09-05 21:43:34

On Wednesday, September 5, 2012 3:35:26 PM, Sascha Hauer wrote:
quoted hunk
From: Philipp Zabel <p.zabel@pengutronix.de>

The i.MX pwm core has two clocks: The ipg clock and the ipg highfreq
(peripheral) clock. The ipg clock has to be enabled for this hardware
to work. The actual pwm output can either be driven by the ipg clock
or the ipg highfreq. The ipg highfreq has the advantage that it runs
even when the SoC is in low power modes.
This patch requests both clocks and enables the ipg clock for
accessing
registers and the peripheral clock to actually turn on the pwm.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/pwm-imx.c |   33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index b234288..5b03ace 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -40,7 +40,8 @@
 #define MX3_PWMCR_EN              (1 << 0)
 
 struct imx_chip {
-	struct clk	*clk;
+	struct clk	*clk_per;
+	struct clk	*clk_ipg;
 
 	int		enabled;
 	void __iomem	*mmio_base;
@@ -105,7 +106,7 @@ static int imx_pwm_config_v2(struct pwm_chip
*chip,
 	unsigned long period_cycles, duty_cycles, prescale;
 	u32 cr;
 
-	c = clk_get_rate(imx->clk);
+	c = clk_get_rate(imx->clk_per);
 	c = c * period_ns;
 	do_div(c, 1000000000);
 	period_cycles = c;
@@ -160,8 +161,15 @@ static int imx_pwm_config(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
+	int ret;
 
-	return imx->config(chip, pwm, duty_ns, period_ns);
+	clk_prepare_enable(imx->clk_ipg);
Why don't you test the return value like in imx_pwm_enable()?
quoted hunk
+
+	ret = imx->config(chip, pwm, duty_ns, period_ns);
+
+	clk_disable_unprepare(imx->clk_ipg);
+
+	return ret;
 }
 
 static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device
 *pwm)
@@ -169,7 +177,7 @@ static int imx_pwm_enable(struct pwm_chip *chip,
struct pwm_device *pwm)
 	struct imx_chip *imx = to_imx_chip(chip);
 	int rc;
 
-	rc = clk_prepare_enable(imx->clk);
+	rc = clk_prepare_enable(imx->clk_per);
 	if (rc)
 		return rc;
 
@@ -186,7 +194,7 @@ static void imx_pwm_disable(struct pwm_chip
*chip, struct pwm_device *pwm)
 
 	imx->set_enable(chip, false);
 
-	clk_disable_unprepare(imx->clk);
+	clk_disable_unprepare(imx->clk_per);
 	imx->enabled = 0;
 }
 
@@ -238,10 +246,19 @@ static int __devinit imx_pwm_probe(struct
platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	imx->clk = devm_clk_get(&pdev->dev, "pwm");
+	imx->clk_per = devm_clk_get(&pdev->dev, "per");
+	if (IS_ERR(imx->clk_per)) {
+		dev_err(&pdev->dev, "getting per clock failed with %ld\n",
+				PTR_ERR(imx->clk_per));
+		return PTR_ERR(imx->clk_per);
+	}
 
-	if (IS_ERR(imx->clk))
-		return PTR_ERR(imx->clk);
+	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(imx->clk_ipg)) {
+		dev_err(&pdev->dev, "getting ipg clock failed with %ld\n",
+				PTR_ERR(imx->clk_ipg));
+		return PTR_ERR(imx->clk_ipg);
+	}
 
 	imx->chip.ops = &imx_pwm_ops;
 	imx->chip.dev = &pdev->dev;
I have reviewed the whole series. Apart from the comments I made, it looks good
to me.

Best regards,
Beno?t

Re: [PATCH 7/8] pwm i.MX: fix clock lookup

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-06 07:15:21

On Wed, Sep 05, 2012 at 11:48:51PM +0200, Beno?t Th?baudeau wrote:
quoted
 
-	c = clk_get_rate(imx->clk);
+	c = clk_get_rate(imx->clk_per);
 	c = c * period_ns;
 	do_div(c, 1000000000);
 	period_cycles = c;
@@ -160,8 +161,15 @@ static int imx_pwm_config(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
+	int ret;
 
-	return imx->config(chip, pwm, duty_ns, period_ns);
+	clk_prepare_enable(imx->clk_ipg);
Why don't you test the return value like in imx_pwm_enable()?
Will do next time.

Sascha
I have reviewed the whole series. Apart from the comments I made, it looks good
to me.
Thanks. I can take this as a reviewed-by, right?

Sascha

-- 
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[PATCH 8/8] ARM i.MX53: Add pwm support

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:35:49

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/boot/dts/imx53.dtsi        |   14 ++++++++++++++
 arch/arm/mach-imx/clk-imx51-imx53.c |    4 ++++
 2 files changed, 18 insertions(+)
diff --git a/arch/arm/boot/dts/imx53.dtsi b/arch/arm/boot/dts/imx53.dtsi
index cd37165..18b9fc3 100644
--- a/arch/arm/boot/dts/imx53.dtsi
+++ b/arch/arm/boot/dts/imx53.dtsi
@@ -189,6 +189,20 @@
 				status = "disabled";
 			};
 
+			pwm1: pwm at 53fb4000 {
+				#pwm-cells = <2>;
+				compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";
+				reg = <0x53fb4000 0x4000>;
+				interrupts = <61>;
+			};
+
+			pwm2: pwm at 53fb8000 {
+				#pwm-cells = <2>;
+				compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";
+				reg = <0x53fb8000 0x4000>;
+				interrupts = <94>;
+			};
+
 			uart1: serial at 53fbc000 {
 				compatible = "fsl,imx53-uart", "fsl,imx21-uart";
 				reg = <0x53fbc000 0x4000>;
diff --git a/arch/arm/mach-imx/clk-imx51-imx53.c b/arch/arm/mach-imx/clk-imx51-imx53.c
index 4bdcaa9..b522411 100644
--- a/arch/arm/mach-imx/clk-imx51-imx53.c
+++ b/arch/arm/mach-imx/clk-imx51-imx53.c
@@ -455,6 +455,10 @@ int __init mx53_clocks_init(unsigned long rate_ckil, unsigned long rate_osc,
 	clk_register_clkdev(clk[ssi1_ipg_gate], NULL, "63fcc000.ssi");
 	clk_register_clkdev(clk[ssi2_ipg_gate], NULL, "50014000.ssi");
 	clk_register_clkdev(clk[ssi3_ipg_gate], NULL, "63fd0000.ssi");
+	clk_register_clkdev(clk[pwm1_ipg_gate], "ipg", "53fb4000.pwm");
+	clk_register_clkdev(clk[pwm1_hf_gate], "per", "53fb4000.pwm");
+	clk_register_clkdev(clk[pwm2_ipg_gate], "ipg", "53fb8000.pwm");
+	clk_register_clkdev(clk[pwm2_hf_gate], "per", "53fb8000.pwm");
 
 	/* set SDHC root clock to 200MHZ*/
 	clk_set_rate(clk[esdhc_a_podf], 200000000);
-- 
1.7.10.4

[PATCH 1/8] pwm i.MX: factor out SoC specific functions

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:35:50

To make the code more flexible.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/pwm-imx.c |  145 ++++++++++++++++++++++++++++---------------------
 1 file changed, 82 insertions(+), 63 deletions(-)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 2a0b353..38270f4 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -46,81 +46,95 @@ struct imx_chip {
 	void __iomem	*mmio_base;
 
 	struct pwm_chip	chip;
+
+	int (*config)(struct pwm_chip *chip,
+		struct pwm_device *pwm, int duty_ns, int period_ns);
 };
 
 #define to_imx_chip(chip)	container_of(chip, struct imx_chip, chip)
 
-static int imx_pwm_config(struct pwm_chip *chip,
+static int imx_pwm_config_v1(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
 
-	if (!(cpu_is_mx1() || cpu_is_mx21())) {
-		unsigned long long c;
-		unsigned long period_cycles, duty_cycles, prescale;
-		u32 cr;
-
-		c = clk_get_rate(imx->clk);
-		c = c * period_ns;
-		do_div(c, 1000000000);
-		period_cycles = c;
-
-		prescale = period_cycles / 0x10000 + 1;
-
-		period_cycles /= prescale;
-		c = (unsigned long long)period_cycles * duty_ns;
-		do_div(c, period_ns);
-		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;
-
-		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_EN;
-
-		if (cpu_is_mx25())
-			cr |= MX3_PWMCR_CLKSRC_IPG;
-		else
-			cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
-
-		writel(cr, imx->mmio_base + MX3_PWMCR);
-	} else if (cpu_is_mx1() || cpu_is_mx21()) {
-		/* The PWM subsystem allows for exact frequencies. However,
-		 * I cannot connect a scope on my device to the PWM line and
-		 * thus cannot provide the program the PWM controller
-		 * exactly. Instead, I'm relying on the fact that the
-		 * Bootloader (u-boot or WinCE+haret) has programmed the PWM
-		 * function group already. So I'll just modify the PWM sample
-		 * register to follow the ratio of duty_ns vs. period_ns
-		 * accordingly.
-		 *
-		 * This is good enough for programming the brightness of
-		 * the LCD backlight.
-		 *
-		 * The real implementation would divide PERCLK[0] first by
-		 * both the prescaler (/1 .. /128) and then by CLKSEL
-		 * (/2 .. /16).
-		 */
-		u32 max = readl(imx->mmio_base + MX1_PWMP);
-		u32 p = max * duty_ns / period_ns;
-		writel(max - p, imx->mmio_base + MX1_PWMS);
-	} else {
-		BUG();
-	}
+	/* The PWM subsystem allows for exact frequencies. However,
+	 * I cannot connect a scope on my device to the PWM line and
+	 * thus cannot provide the program the PWM controller
+	 * exactly. Instead, I'm relying on the fact that the
+	 * Bootloader (u-boot or WinCE+haret) has programmed the PWM
+	 * function group already. So I'll just modify the PWM sample
+	 * register to follow the ratio of duty_ns vs. period_ns
+	 * accordingly.
+	 *
+	 * This is good enough for programming the brightness of
+	 * the LCD backlight.
+	 *
+	 * The real implementation would divide PERCLK[0] first by
+	 * both the prescaler (/1 .. /128) and then by CLKSEL
+	 * (/2 .. /16).
+	 */
+	u32 max = readl(imx->mmio_base + MX1_PWMP);
+	u32 p = max * duty_ns / period_ns;
+	writel(max - p, imx->mmio_base + MX1_PWMS);
+
+	return 0;
+}
+
+static int imx_pwm_config_v2(struct pwm_chip *chip,
+		struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+	struct imx_chip *imx = to_imx_chip(chip);
+	unsigned long long c;
+	unsigned long period_cycles, duty_cycles, prescale;
+	u32 cr;
+
+	c = clk_get_rate(imx->clk);
+	c = c * period_ns;
+	do_div(c, 1000000000);
+	period_cycles = c;
+
+	prescale = period_cycles / 0x10000 + 1;
+
+	period_cycles /= prescale;
+	c = (unsigned long long)period_cycles * duty_ns;
+	do_div(c, period_ns);
+	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;
+
+	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_EN;
+
+	if (cpu_is_mx25())
+		cr |= MX3_PWMCR_CLKSRC_IPG;
+	else
+		cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
+
+	writel(cr, imx->mmio_base + MX3_PWMCR);
 
 	return 0;
 }
 
+static int imx_pwm_config(struct pwm_chip *chip,
+		struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+	struct imx_chip *imx = to_imx_chip(chip);
+
+	return imx->config(chip, pwm, duty_ns, period_ns);
+}
+
 static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
@@ -187,6 +201,11 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
 	if (imx->mmio_base == NULL)
 		return -EADDRNOTAVAIL;
 
+	if (cpu_is_mx1() || cpu_is_mx21())
+		imx->config = imx_pwm_config_v1;
+	else
+		imx->config = imx_pwm_config_v2;
+
 	ret = pwmchip_add(&imx->chip);
 	if (ret < 0)
 		return ret;
-- 
1.7.10.4

[PATCH 6/8] pwm i.MX: use per clock unconditionally

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:35:52

The i.MX pwm core has two clocks: The ipg clock and the ipg highfreq
(peripheral) clock. The ipg clock has to be enabled for this hardware
to work. The actual pwm output can either be driven by the ipg clock
or the ipg highfreq. The ipg highfreq has the advantage that it runs
even when the SoC is in low power modes.
Use the always running clock also on i.MX25.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/pwm-imx.c |    7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index af77045..b234288 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -131,16 +131,11 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
 
 	cr = MX3_PWMCR_PRESCALER(prescale) |
 		MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
-		MX3_PWMCR_DBGEN;
+		MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH;
 
 	if (imx->enabled)
 		cr |= MX3_PWMCR_EN;
 
-	if (cpu_is_mx25())
-		cr |= MX3_PWMCR_CLKSRC_IPG;
-	else
-		cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
-
 	writel(cr, imx->mmio_base + MX3_PWMCR);
 
 	return 0;
-- 
1.7.10.4

[PATCH 3/8] pwm i.MX: add functions to enable/disable pwm.

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:35:56

We used to enable/disable the pwm only by switching the
clock on or off. Instead, use the dedicated register bits.
These differ on different SoCs, so introduce a SoC specific
function for this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/pwm-imx.c |   48 ++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 44 insertions(+), 4 deletions(-)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 0f244e6..3fc4ae8 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -25,6 +25,7 @@
 #define MX1_PWMS    0x04   /* PWM Sample Register */
 #define MX1_PWMP    0x08   /* PWM Period Register */
 
+#define MX1_PWMC_EN		(1 << 4)
 
 /* i.MX27, i.MX31, i.MX35 share the same PWM function block: */
 
@@ -49,6 +50,7 @@ struct imx_chip {
 
 	int (*config)(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns);
+	void (*set_enable)(struct pwm_chip *chip, bool enable);
 };
 
 #define to_imx_chip(chip)	container_of(chip, struct imx_chip, chip)
@@ -81,6 +83,21 @@ 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)
+{
+	struct imx_chip *imx = to_imx_chip(chip);
+	u32 val;
+
+	val = readl(imx->mmio_base + MX1_PWMC);
+
+	if (enable)
+		val |= MX1_PWMC_EN;
+	else
+		val &= ~MX1_PWMC_EN;
+
+	writel(val, imx->mmio_base + MX1_PWMC);
+}
+
 static int imx_pwm_config_v2(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns)
 {
@@ -115,7 +132,10 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
 
 	cr = MX3_PWMCR_PRESCALER(prescale) |
 		MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
-		MX3_PWMCR_DBGEN | MX3_PWMCR_EN;
+		MX3_PWMCR_DBGEN;
+
+	if (imx->enabled)
+		cr |= MX3_PWMCR_EN;
 
 	if (cpu_is_mx25())
 		cr |= MX3_PWMCR_CLKSRC_IPG;
@@ -127,6 +147,21 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
 	return 0;
 }
 
+static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
+{
+	struct imx_chip *imx = to_imx_chip(chip);
+	u32 val;
+
+	val = readl(imx->mmio_base + MX3_PWMCR);
+
+	if (enable)
+		val |= MX3_PWMCR_EN;
+	else
+		val &= ~MX3_PWMCR_EN;
+
+	writel(val, imx->mmio_base + MX3_PWMCR);
+}
+
 static int imx_pwm_config(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns)
 {
@@ -144,6 +179,8 @@ static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	if (rc)
 		return rc;
 
+	imx->set_enable(chip, true);
+
 	imx->enabled = 1;
 
 	return 0;
@@ -153,7 +190,7 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
 
-	writel(0, imx->mmio_base + MX3_PWMCR);
+	imx->set_enable(chip, false);
 
 	clk_disable_unprepare(imx->clk);
 	imx->enabled = 0;
@@ -198,10 +235,13 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
 	if (imx->mmio_base == NULL)
 		return -EADDRNOTAVAIL;
 
-	if (cpu_is_mx1() || cpu_is_mx21())
+	if (cpu_is_mx1() || cpu_is_mx21()) {
 		imx->config = imx_pwm_config_v1;
-	else
+		imx->set_enable = imx_pwm_set_enable_v1;
+	} else {
 		imx->config = imx_pwm_config_v2;
+		imx->set_enable = imx_pwm_set_enable_v2;
+	}
 
 	ret = pwmchip_add(&imx->chip);
 	if (ret < 0)
-- 
1.7.10.4

[PATCH 2/8] pwm i.MX: remove unnecessary if in pwm_[en|dis]able

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:36:08

The pwm core makes sure that pwm_enable/disable are called only
once. Still keep the enabled state since we will need it in
pwm_config.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/pwm-imx.c |   25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 38270f4..0f244e6 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -42,7 +42,7 @@
 struct imx_chip {
 	struct clk	*clk;
 
-	int		clk_enabled;
+	int		enabled;
 	void __iomem	*mmio_base;
 
 	struct pwm_chip	chip;
@@ -138,14 +138,15 @@ static int imx_pwm_config(struct pwm_chip *chip,
 static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
-	int rc = 0;
+	int rc;
 
-	if (!imx->clk_enabled) {
-		rc = clk_prepare_enable(imx->clk);
-		if (!rc)
-			imx->clk_enabled = 1;
-	}
-	return rc;
+	rc = clk_prepare_enable(imx->clk);
+	if (rc)
+		return rc;
+
+	imx->enabled = 1;
+
+	return 0;
 }
 
 static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -154,10 +155,8 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	writel(0, imx->mmio_base + MX3_PWMCR);
 
-	if (imx->clk_enabled) {
-		clk_disable_unprepare(imx->clk);
-		imx->clk_enabled = 0;
-	}
+	clk_disable_unprepare(imx->clk);
+	imx->enabled = 0;
 }
 
 static struct pwm_ops imx_pwm_ops = {
@@ -189,8 +188,6 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
 	imx->chip.base = -1;
 	imx->chip.npwm = 1;
 
-	imx->clk_enabled = 0;
-
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (r == NULL) {
 		dev_err(&pdev->dev, "no memory resource defined\n");
-- 
1.7.10.4

[PATCH 5/8] pwm i.MX: add devicetree support

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-05 13:36:09

From: Philipp Zabel <p.zabel@pengutronix.de>

At the same time remove platform based support. No user for
this driver has made it into mainline so far, so all we break
is out of tree stuff.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 Documentation/devicetree/bindings/pwm/imx-pwm.txt |   17 ++++++++
 drivers/pwm/pwm-imx.c                             |   45 ++++++++++++++++-----
 2 files changed, 52 insertions(+), 10 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pwm/imx-pwm.txt
diff --git a/Documentation/devicetree/bindings/pwm/imx-pwm.txt b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
new file mode 100644
index 0000000..9b9b185
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
@@ -0,0 +1,17 @@
+Freescale i.MX PWM controller
+
+Required properties:
+- compatible: should be "fsl,<soc>-pwm"
+- reg: physical base address and length of the controller's registers
+- #pwm-cells: should be 2.  The first cell specifies the per-chip index
+  of the PWM to use and the second cell is the duty cycle in nanoseconds.
+- interrupts: The interrupt for the pwm controller
+
+Example:
+
+pwm1: pwm at 53fb4000 {
+	#pwm-cells = <2>;
+	compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";
+	reg = <0x53fb4000 0x4000>;
+	interrupts = <61>;
+};
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index a689144..af77045 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -16,8 +16,7 @@
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/pwm.h>
-#include <mach/hardware.h>
-
+#include <linux/of_device.h>
 
 /* i.MX1 and i.MX21 share the same PWM function block: */
 
@@ -203,12 +202,41 @@ static struct pwm_ops imx_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
+struct imx_pwm_data {
+	int (*config)(struct pwm_chip *chip,
+		struct pwm_device *pwm, int duty_ns, int period_ns);
+	void (*set_enable)(struct pwm_chip *chip, bool enable);
+};
+
+static struct imx_pwm_data imx_pwm_data_v1 = {
+	.config = imx_pwm_config_v1,
+	.set_enable = imx_pwm_set_enable_v1,
+};
+
+static struct imx_pwm_data imx_pwm_data_v2 = {
+	.config = imx_pwm_config_v2,
+	.set_enable = imx_pwm_set_enable_v2,
+};
+
+static const struct of_device_id imx_pwm_dt_ids[] = {
+	{ .compatible = "fsl,imx1-pwm", .data = &imx_pwm_data_v1, },
+	{ .compatible = "fsl,imx27-pwm", .data = &imx_pwm_data_v2, },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_pwm_dt_ids);
+
 static int __devinit imx_pwm_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *of_id =
+			of_match_device(imx_pwm_dt_ids, &pdev->dev);
+	struct imx_pwm_data *data;
 	struct imx_chip *imx;
 	struct resource *r;
 	int ret = 0;
 
+	if (!of_id)
+		return -ENODEV;
+
 	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
 	if (imx == NULL) {
 		dev_err(&pdev->dev, "failed to allocate memory\n");
@@ -235,13 +263,9 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
 	if (imx->mmio_base == NULL)
 		return -EADDRNOTAVAIL;
 
-	if (cpu_is_mx1() || cpu_is_mx21()) {
-		imx->config = imx_pwm_config_v1;
-		imx->set_enable = imx_pwm_set_enable_v1;
-	} else {
-		imx->config = imx_pwm_config_v2;
-		imx->set_enable = imx_pwm_set_enable_v2;
-	}
+	data = of_id->data;
+	imx->config = data->config;
+	imx->set_enable = data->set_enable;
 
 	ret = pwmchip_add(&imx->chip);
 	if (ret < 0)
@@ -264,7 +288,8 @@ static int __devexit imx_pwm_remove(struct platform_device *pdev)
 
 static struct platform_driver imx_pwm_driver = {
 	.driver		= {
-		.name	= "mxc_pwm",
+		.name	= "imx-pwm",
+		.of_match_table = of_match_ptr(imx_pwm_dt_ids),
 	},
 	.probe		= imx_pwm_probe,
 	.remove		= __devexit_p(imx_pwm_remove),
-- 
1.7.10.4

Re: [PATCH 5/8] pwm i.MX: add devicetree support

From: Benoît Thébaudeau <hidden>
Date: 2012-09-05 21:37:23

On Wednesday, September 5, 2012 3:35:24 PM, Sascha Hauer wrote:
quoted hunk
From: Philipp Zabel <p.zabel@pengutronix.de>

At the same time remove platform based support. No user for
this driver has made it into mainline so far, so all we break
is out of tree stuff.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 Documentation/devicetree/bindings/pwm/imx-pwm.txt |   17 ++++++++
 drivers/pwm/pwm-imx.c                             |   45
 ++++++++++++++++-----
 2 files changed, 52 insertions(+), 10 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pwm/imx-pwm.txt
diff --git a/Documentation/devicetree/bindings/pwm/imx-pwm.txt
b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
new file mode 100644
index 0000000..9b9b185
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
@@ -0,0 +1,17 @@
+Freescale i.MX PWM controller
+
+Required properties:
+- compatible: should be "fsl,<soc>-pwm"
+- reg: physical base address and length of the controller's
registers
+- #pwm-cells: should be 2.  The first cell specifies the per-chip
index
+  of the PWM to use and the second cell is the duty cycle in
nanoseconds.
+- interrupts: The interrupt for the pwm controller
+
+Example:
+
+pwm1: pwm at 53fb4000 {
+	#pwm-cells = <2>;
+	compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";
+	reg = <0x53fb4000 0x4000>;
+	interrupts = <61>;
+};
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index a689144..af77045 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -16,8 +16,7 @@
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/pwm.h>
-#include <mach/hardware.h>
-
+#include <linux/of_device.h>
 
 /* i.MX1 and i.MX21 share the same PWM function block: */
 
@@ -203,12 +202,41 @@ static struct pwm_ops imx_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
+struct imx_pwm_data {
+	int (*config)(struct pwm_chip *chip,
+		struct pwm_device *pwm, int duty_ns, int period_ns);
+	void (*set_enable)(struct pwm_chip *chip, bool enable);
+};
+
+static struct imx_pwm_data imx_pwm_data_v1 = {
+	.config = imx_pwm_config_v1,
+	.set_enable = imx_pwm_set_enable_v1,
+};
+
+static struct imx_pwm_data imx_pwm_data_v2 = {
+	.config = imx_pwm_config_v2,
+	.set_enable = imx_pwm_set_enable_v2,
+};
+
+static const struct of_device_id imx_pwm_dt_ids[] = {
+	{ .compatible = "fsl,imx1-pwm", .data = &imx_pwm_data_v1, },
+	{ .compatible = "fsl,imx27-pwm", .data = &imx_pwm_data_v2, },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_pwm_dt_ids);
+
 static int __devinit imx_pwm_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *of_id =
+			of_match_device(imx_pwm_dt_ids, &pdev->dev);
+	struct imx_pwm_data *data;
 	struct imx_chip *imx;
 	struct resource *r;
 	int ret = 0;
 
+	if (!of_id)
+		return -ENODEV;
+
 	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
 	if (imx == NULL) {
 		dev_err(&pdev->dev, "failed to allocate memory\n");
@@ -235,13 +263,9 @@ static int __devinit imx_pwm_probe(struct
platform_device *pdev)
 	if (imx->mmio_base == NULL)
 		return -EADDRNOTAVAIL;
 
-	if (cpu_is_mx1() || cpu_is_mx21()) {
-		imx->config = imx_pwm_config_v1;
-		imx->set_enable = imx_pwm_set_enable_v1;
-	} else {
-		imx->config = imx_pwm_config_v2;
-		imx->set_enable = imx_pwm_set_enable_v2;
-	}
+	data = of_id->data;
+	imx->config = data->config;
+	imx->set_enable = data->set_enable;
 
 	ret = pwmchip_add(&imx->chip);
 	if (ret < 0)
@@ -264,7 +288,8 @@ static int __devexit imx_pwm_remove(struct
platform_device *pdev)
 
 static struct platform_driver imx_pwm_driver = {
 	.driver		= {
-		.name	= "mxc_pwm",
+		.name	= "imx-pwm",
+		.of_match_table = of_match_ptr(imx_pwm_dt_ids),
 	},
 	.probe		= imx_pwm_probe,
 	.remove		= __devexit_p(imx_pwm_remove),
Since this is supposed to remove platform-based support, why don't you also
remove the PWM stuff from arch/arm/plat-mxc and
arch/arm/mach-imx/devices-imx*.h?

Best regards,
Beno?t

Re: [PATCH 5/8] pwm i.MX: add devicetree support

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2012-09-06 06:58:44

On Wed, Sep 05, 2012 at 11:42:34PM +0200, Beno?t Th?baudeau wrote:
Since this is supposed to remove platform-based support, why don't you also
remove the PWM stuff from arch/arm/plat-mxc and
arch/arm/mach-imx/devices-imx*.h?
Simple answer: I was too lazy yesterday. I will include it in the next
round.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v2] pwm i.MX: add devicetree support

From: Shawn Guo <hidden>
Date: 2012-09-06 08:19:50

On Wed, Sep 05, 2012 at 03:35:19PM +0200, Sascha Hauer wrote:
Changes since v1:

- Add devicetree binding documentation
- Merge 5/9 and 9/9
- fix #pwm-cells (must be 2 instead of 3)
- fix wrong name in MODULE_DEVICE_TABLE
- drop platform based probing while introducing devicetree based probe

----------------------------------------------------------------
Philipp Zabel (2):
      pwm i.MX: add devicetree support
      pwm i.MX: fix clock lookup

Sascha Hauer (6):
      pwm i.MX: factor out SoC specific functions
      pwm i.MX: remove unnecessary if in pwm_[en|dis]able
      pwm i.MX: add functions to enable/disable pwm.
      pwm i.MX: Use module_platform_driver
      pwm i.MX: use per clock unconditionally
      ARM i.MX53: Add pwm support
For the series,

Reviewed-by: Shawn Guo <redacted>
 Documentation/devicetree/bindings/pwm/imx-pwm.txt |   17 ++
 arch/arm/boot/dts/imx53.dtsi                      |   14 ++
 arch/arm/mach-imx/clk-imx51-imx53.c               |    4 +
 drivers/pwm/pwm-imx.c                             |  275 ++++++++++++++-------
 4 files changed, 214 insertions(+), 96 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pwm/imx-pwm.txt
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