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Commit 333b08ee authored by Philip, Avinash's avatar Philip, Avinash Committed by Thierry Reding
Browse files

pwm: tiecap: Add device-tree binding 



This patch
1. Add support for device-tree binding for ECAP APWM driver.
2. Set size of pwm-cells set to 3 to support PWM channel number, PWM
   period & polarity configuration from device tree.
3. Add enable/disable clock gating in PWM subsystem common config space.
4. When here set .owner member in platform_driver structure to
   THIS_MODULE.

Signed-off-by: default avatarPhilip, Avinash <avinashphilip@ti.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
parent af0ba001

Documentation/devicetree/bindings/pwm/pwm-tiecap.txt

0 → 100644
+23 −0
Original line number Diff line number Diff line 
TI SOC ECAP based APWM controller



Required properties:

- compatible: Must be "ti,am33xx-ecap"

- #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 in nanoseconds and bit 0 in the third cell is used to

  encode the polarity of PWM output. Set bit 0 of the third in PWM specifier

  to 1 for inverse polarity & set to 0 for normal polarity.

- reg: physical base address and size of the registers map.



Optional properties:

- ti,hwmods: Name of the hwmod associated to the ECAP:

  "ecap<x>", <x> being the 0-based instance number from the HW spec



Example:



ecap0: ecap@0 {

	compatible = "ti,am33xx-ecap";

	#pwm-cells = <3>;

	reg = <0x48300100 0x80>;

	ti,hwmods = "ecap0";

};

drivers/pwm/pwm-tiecap.c

+41 −1
Original line number Diff line number Diff line
@@ -25,6 +25,9 @@ 
#include <linux/clk.h>

#include <linux/pm_runtime.h>

#include <linux/pwm.h>

#include <linux/of_device.h>



#include "pwm-tipwmss.h"



/* ECAP registers and bits definitions */

#define CAP1			0x08
@@ -184,12 +187,19 @@ static const struct pwm_ops ecap_pwm_ops = { 
	.owner		= THIS_MODULE,

};



static const struct of_device_id ecap_of_match[] = {

	{ .compatible	= "ti,am33xx-ecap" },

	{},

};

MODULE_DEVICE_TABLE(of, ecap_of_match);



static int __devinit ecap_pwm_probe(struct platform_device *pdev)

{

	int ret;

	struct resource *r;

	struct clk *clk;

	struct ecap_pwm_chip *pc;

	u16 status;



	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);

	if (!pc) {
@@ -211,6 +221,8 @@ static int __devinit ecap_pwm_probe(struct platform_device *pdev) 


	pc->chip.dev = &pdev->dev;

	pc->chip.ops = &ecap_pwm_ops;

	pc->chip.of_xlate = of_pwm_xlate_with_flags;

	pc->chip.of_pwm_n_cells = 3;

	pc->chip.base = -1;

	pc->chip.npwm = 1;
@@ -231,14 +243,40 @@ static int __devinit ecap_pwm_probe(struct platform_device *pdev) 
	}



	pm_runtime_enable(&pdev->dev);

	pm_runtime_get_sync(&pdev->dev);



	status = pwmss_submodule_state_change(pdev->dev.parent,

			PWMSS_ECAPCLK_EN);

	if (!(status & PWMSS_ECAPCLK_EN_ACK)) {

		dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");

		ret = -EINVAL;

		goto pwmss_clk_failure;

	}



	pm_runtime_put_sync(&pdev->dev);



	platform_set_drvdata(pdev, pc);

	return 0;



pwmss_clk_failure:

	pm_runtime_put_sync(&pdev->dev);

	pm_runtime_disable(&pdev->dev);

	pwmchip_remove(&pc->chip);

	return ret;

}



static int __devexit ecap_pwm_remove(struct platform_device *pdev)

{

	struct ecap_pwm_chip *pc = platform_get_drvdata(pdev);



	pm_runtime_get_sync(&pdev->dev);

	/*

	 * Due to hardware misbehaviour, acknowledge of the stop_req

	 * is missing. Hence checking of the status bit skipped.

	 */

	pwmss_submodule_state_change(pdev->dev.parent, PWMSS_ECAPCLK_STOP_REQ);

	pm_runtime_put_sync(&pdev->dev);



	pm_runtime_put_sync(&pdev->dev);

	pm_runtime_disable(&pdev->dev);

	return pwmchip_remove(&pc->chip);
@@ -247,6 +285,8 @@ static int __devexit ecap_pwm_remove(struct platform_device *pdev) 
static struct platform_driver ecap_pwm_driver = {

	.driver = {

		.name	= "ecap",

		.owner	= THIS_MODULE,

		.of_match_table = ecap_of_match,

	},

	.probe = ecap_pwm_probe,

	.remove = __devexit_p(ecap_pwm_remove),