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pwm: tiecap: Add device-tree binding

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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: Philip, 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: Thierry Reding <thierry.reding@avionic-design.de>
This commit is contained in:
Philip, Avinash 2012-11-27 14:18:09 +05:30 committed by Thierry Reding
parent af0ba001d2
commit 333b08ee8c
2 changed files with 64 additions and 1 deletions
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23
Documentation/devicetree/bindings/pwm/pwm-tiecap.txt Normal file
View File

@ -0,0 +1,23 @@
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";
};

42
drivers/pwm/pwm-tiecap.c
View File

@ -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);
@ -246,7 +284,9 @@ static int __devexit ecap_pwm_remove(struct platform_device *pdev)
static struct platform_driver ecap_pwm_driver = {
.driver = {
.name = "ecap",
.name = "ecap",
.owner = THIS_MODULE,
.of_match_table = ecap_of_match,
},
.probe = ecap_pwm_probe,
.remove = __devexit_p(ecap_pwm_remove),