[PATCH v4 04/11] pwm: pwm-tiecap: Add device-tree binding support for APWM driver
From: Philip, Avinash
Date: Wed Nov 21 2012 - 08:13:23 EST
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@xxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
Cc: Rob Landley <rob@xxxxxxxxxxx>
---
Changes since v3:
- Replace pwmss.h with pwm-tipwmss.h
Changes since v2:
- Add of_pwm_xlate_with_flags function support
Changes since v1:
- Add separate patch for pinctrl support
- Add conditional check for PWM subsystem clock enable.
- Combined with HWMOD changes & DT bindings.
- Remove the custom of_xlate support.
:000000 100644 0000000... 131e8c1... A Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
:100644 100644 d6d4cf0... e0bcc85... M drivers/pwm/pwm-tiecap.c
.../devicetree/bindings/pwm/pwm-tiecap.txt | 23 ++++++++++
drivers/pwm/pwm-tiecap.c | 44 +++++++++++++++++++-
2 files changed, 66 insertions(+), 1 deletions(-)
diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt b/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
new file mode 100644
index 0000000..131e8c1
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
@@ -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";
+};
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index d6d4cf0..e0bcc85 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -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 +187,21 @@ 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 +223,8 @@ 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 +245,40 @@ 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 +286,9 @@ 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),
--
1.7.0.4
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