[PATCH 5/8] pwm: pwm-tiehrpwm: Add device-tree binding support for EHRPWM driver

Philip, Avinash avinashphilip at ti.com
Mon Nov 5 04:12:26 EST 2012


Add support for device-tree binding for EHRWPM driver.
Also size of #pwm-cells set to 3 to support PWM channel number, PWM
period & polarity configuration from device tree.
Also enable clock gating in PWM subsystem common config space.
Also when here set .owner member in platform_driver structure to
THIS_MODULE.

Signed-off-by: Philip, Avinash <avinashphilip at ti.com>
Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: Rob Landley <rob at landley.net>
---
Second version
	- Combined with HWMOD changes & DT bindings.
	- Remove the custom of_xlate support.

:000000 100644 0000000... aa2ed0a... A	Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
:100644 100644 d3c1dff... 1e63652... M	drivers/pwm/pwm-tiehrpwm.c
 .../devicetree/bindings/pwm/pwm-tiehrpwm.txt       |   25 +++++++++++++
 drivers/pwm/pwm-tiehrpwm.c                         |   37 ++++++++++++++++++-
 2 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt b/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
new file mode 100644
index 0000000..aa2ed0a
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
@@ -0,0 +1,25 @@
+TI SOC EHRPWM based PWM controller
+
+Required properties:
+- compatible : Must be "ti,am33xx-ehrpwm"
+- #pwm-cells: Should be 3. Number of cells being used to specify PWM property.
+  First cell specifies the per-chip index of the PWM to use, the second
+  cell is the period cycle in nanoseconds and bit 0 in the third cell is
+  used to encode the polarity of PWM output.
+- reg: physical base address and size of the registers map.
+
+Optional properties:
+- ti,hwmods: Name of the hwmod associated to the EHRPWM:
+  "ehrpwm<x>", <x> being the 0-based instance number from the HW spec
+- tbclkgating: platforms require tbclk gating from control module
+  should populate
+
+Example:
+
+ehrpwm0: ehrpwm at 0 {
+	compatible = "ti,am33xx-ehrpwm";
+	#pwm-cells = <3>;
+	reg = <0x48300200 0x100>;
+	ti,hwmods = "ehrpwm0";
+	tbclkgating;
+};
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index d3c1dff..1e63652 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -25,6 +25,10 @@
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/pm_runtime.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+
+#include "tipwmss.h"
 
 /* EHRPWM registers and bits definitions */
 
@@ -107,6 +111,10 @@
 #define AQCSFRC_CSFA_FRCHIGH	BIT(1)
 #define AQCSFRC_CSFA_DISSWFRC	(BIT(1) | BIT(0))
 
+#define EPWMCLK_EN_SHIFT	8
+
+#define PWM_CELL_SIZE		3
+
 #define NUM_PWM_CHANNEL		2	/* EHRPWM channels */
 
 struct ehrpwm_pwm_chip {
@@ -392,12 +400,27 @@ static const struct pwm_ops ehrpwm_pwm_ops = {
 	.owner		= THIS_MODULE,
 };
 
+#ifdef CONFIG_OF
+static const struct of_device_id ehrpwm_of_match[] = {
+	{
+		.compatible	= "ti,am33xx-ehrpwm",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
+#endif
+
 static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct resource *r;
 	struct clk *clk;
 	struct ehrpwm_pwm_chip *pc;
+	struct pinctrl *pinctrl;
+
+	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+	if (IS_ERR(pinctrl))
+		dev_warn(&pdev->dev, "failed to configure pins from driver\n");
 
 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc) {
@@ -419,6 +442,7 @@ static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
 
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = &ehrpwm_pwm_ops;
+	pc->chip.of_pwm_n_cells = PWM_CELL_SIZE;
 	pc->chip.base = -1;
 	pc->chip.npwm = NUM_PWM_CHANNEL;
 
@@ -437,8 +461,11 @@ static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 		return ret;
 	}
-
 	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+	pwmss_submodule_state_change(pdev->dev.parent, EPWMCLK_EN_SHIFT, true);
+	pm_runtime_put_sync(&pdev->dev);
+
 	platform_set_drvdata(pdev, pc);
 	return 0;
 }
@@ -447,6 +474,10 @@ static int __devexit ehrpwm_pwm_remove(struct platform_device *pdev)
 {
 	struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
 
+	pm_runtime_get_sync(&pdev->dev);
+	pwmss_submodule_state_change(pdev->dev.parent, EPWMCLK_EN_SHIFT, false);
+	pm_runtime_put_sync(&pdev->dev);
+
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	return pwmchip_remove(&pc->chip);
@@ -454,7 +485,9 @@ static int __devexit ehrpwm_pwm_remove(struct platform_device *pdev)
 
 static struct platform_driver ehrpwm_pwm_driver = {
 	.driver = {
-		.name = "ehrpwm",
+		.name	= "ehrpwm",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(ehrpwm_of_match),
 	},
 	.probe = ehrpwm_pwm_probe,
 	.remove = __devexit_p(ehrpwm_pwm_remove),
-- 
1.7.0.4




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