[PATCH v5 04/12] pwm: tiecap: Add device-tree binding
From: Philip, Avinash <hidden>
Date: 2012-11-27 08:50:17
Also in:
linux-arm-kernel, linux-omap, lkml
Subsystem:
open firmware and flattened device tree bindings, pwm subsystem, the rest · Maintainers:
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Uwe Kleine-König, Linus Torvalds
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 <redacted>
Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
Cc: Rob Landley <rob-VoJi6FS/r0vR7s880joybQ@public.gmane.org>
---
Changes since v4:
- Made dt match property in single line for consistency
- Corrected commit subject for consistency.
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.
.../devicetree/bindings/pwm/pwm-tiecap.txt | 23 +++++++++++
drivers/pwm/pwm-tiecap.c | 42 +++++++++++++++++++-
2 files changed, 64 insertions(+), 1 deletions(-)
create mode 100644 Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
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..0f541c5 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 +187,19 @@ 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),
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1.7.0.4