From 7299ab70e68e20e70cb45fe4ab4b6029fe964acd Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 14 Dec 2011 11:10:32 +0100 Subject: pwm: Add device tree support This patch adds helpers to support device tree bindings for the generic PWM API. Device tree binding documentation for PWM controllers is also provided. Acked-by: Arnd Bergmann Reviewed-by: Shawn Guo Signed-off-by: Thierry Reding --- Documentation/devicetree/bindings/pwm/pwm.txt | 57 +++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/pwm.txt (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt new file mode 100644 index 000000000000..73ec962bfe8c --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pwm.txt @@ -0,0 +1,57 @@ +Specifying PWM information for devices +====================================== + +1) PWM user nodes +----------------- + +PWM users should specify a list of PWM devices that they want to use +with a property containing a 'pwm-list': + + pwm-list ::= [pwm-list] + single-pwm ::= + pwm-phandle : phandle to PWM controller node + pwm-specifier : array of #pwm-cells specifying the given PWM + (controller specific) + +PWM properties should be named "pwms". The exact meaning of each pwms +property must be documented in the device tree binding for each device. +An optional property "pwm-names" may contain a list of strings to label +each of the PWM devices listed in the "pwms" property. If no "pwm-names" +property is given, the name of the user node will be used as fallback. + +Drivers for devices that use more than a single PWM device can use the +"pwm-names" property to map the name of the PWM device requested by the +pwm_get() call to an index into the list given by the "pwms" property. + +The following example could be used to describe a PWM-based backlight +device: + + pwm: pwm { + #pwm-cells = <2>; + }; + + [...] + + bl: backlight { + pwms = <&pwm 0 5000000>; + pwm-names = "backlight"; + }; + +pwm-specifier typically encodes the chip-relative PWM number and the PWM +period in nanoseconds. Note that in the example above, specifying the +"pwm-names" is redundant because the name "backlight" would be used as +fallback anyway. + +2) PWM controller nodes +----------------------- + +PWM controller nodes must specify the number of cells used for the +specifier using the '#pwm-cells' property. + +An example PWM controller might look like this: + + pwm: pwm@7000a000 { + compatible = "nvidia,tegra20-pwm"; + reg = <0x7000a000 0x100>; + #pwm-cells = <2>; + }; -- cgit v1.2.3 From 140fd977dc46bc750258f082cdf1cfea79dc1d14 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 21 Dec 2011 08:04:13 +0100 Subject: pwm: tegra: Add device tree support Add auxdata to instantiate the PWFM controller from a device tree, include the corresponding nodes in the dtsi files for Tegra 20 and Tegra 30 and add binding documentation. Acked-by: Stephen Warren Signed-off-by: Thierry Reding --- .../devicetree/bindings/pwm/nvidia,tegra20-pwm.txt | 18 ++++++++++++++++++ arch/arm/boot/dts/tegra20.dtsi | 6 ++++++ arch/arm/boot/dts/tegra30.dtsi | 6 ++++++ arch/arm/mach-tegra/board-dt-tegra20.c | 1 + arch/arm/mach-tegra/board-dt-tegra30.c | 3 +++ drivers/pwm/pwm-tegra.c | 11 +++++++++++ 6 files changed, 45 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt new file mode 100644 index 000000000000..bbbeedb4ec05 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt @@ -0,0 +1,18 @@ +Tegra SoC PWFM controller + +Required properties: +- compatible: should be one of: + - "nvidia,tegra20-pwm" + - "nvidia,tegra30-pwm" +- reg: physical base address and length of the controller's registers +- #pwm-cells: On Tegra the number of cells used to specify a PWM is 2. The + first cell specifies the per-chip index of the PWM to use and the second + cell is the duty cycle in nanoseconds. + +Example: + + pwm: pwm@7000a000 { + compatible = "nvidia,tegra20-pwm"; + reg = <0x7000a000 0x100>; + #pwm-cells = <2>; + }; diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi index c417d67e9027..846af573f649 100644 --- a/arch/arm/boot/dts/tegra20.dtsi +++ b/arch/arm/boot/dts/tegra20.dtsi @@ -123,6 +123,12 @@ status = "disable"; }; + pwm { + compatible = "nvidia,tegra20-pwm"; + reg = <0x7000a000 0x100>; + #pwm-cells = <2>; + }; + i2c@7000c000 { compatible = "nvidia,tegra20-i2c"; reg = <0x7000c000 0x100>; diff --git a/arch/arm/boot/dts/tegra30.dtsi b/arch/arm/boot/dts/tegra30.dtsi index 2dcc09e784b5..f7f428e81e3a 100644 --- a/arch/arm/boot/dts/tegra30.dtsi +++ b/arch/arm/boot/dts/tegra30.dtsi @@ -117,6 +117,12 @@ status = "disable"; }; + pwm { + compatible = "nvidia,tegra30-pwm", "nvidia,tegra20-pwm"; + reg = <0x7000a000 0x100>; + #pwm-cells = <2>; + }; + i2c@7000c000 { compatible = "nvidia,tegra30-i2c", "nvidia,tegra20-i2c"; reg = <0x7000c000 0x100>; diff --git a/arch/arm/mach-tegra/board-dt-tegra20.c b/arch/arm/mach-tegra/board-dt-tegra20.c index eb7249db50a5..962f1a1b12e9 100644 --- a/arch/arm/mach-tegra/board-dt-tegra20.c +++ b/arch/arm/mach-tegra/board-dt-tegra20.c @@ -64,6 +64,7 @@ struct of_dev_auxdata tegra20_auxdata_lookup[] __initdata = { &tegra_ehci2_pdata), OF_DEV_AUXDATA("nvidia,tegra20-ehci", TEGRA_USB3_BASE, "tegra-ehci.2", &tegra_ehci3_pdata), + OF_DEV_AUXDATA("nvidia,tegra20-pwm", TEGRA_PWFM_BASE, "tegra-pwm", NULL), {} }; diff --git a/arch/arm/mach-tegra/board-dt-tegra30.c b/arch/arm/mach-tegra/board-dt-tegra30.c index 4f76fa7a5da3..ffc6cae3eb2c 100644 --- a/arch/arm/mach-tegra/board-dt-tegra30.c +++ b/arch/arm/mach-tegra/board-dt-tegra30.c @@ -33,6 +33,8 @@ #include #include +#include + #include "board.h" #include "clock.h" @@ -52,6 +54,7 @@ struct of_dev_auxdata tegra30_auxdata_lookup[] __initdata = { OF_DEV_AUXDATA("nvidia,tegra20-i2c", 0x7000C700, "tegra-i2c.3", NULL), OF_DEV_AUXDATA("nvidia,tegra20-i2c", 0x7000D000, "tegra-i2c.4", NULL), OF_DEV_AUXDATA("nvidia,tegra30-ahub", 0x70080000, "tegra30-ahub", NULL), + OF_DEV_AUXDATA("nvidia,tegra30-pwm", TEGRA_PWFM_BASE, "tegra-pwm", NULL), {} }; diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c index 0950142d1913..472b74e8221a 100644 --- a/drivers/pwm/pwm-tegra.c +++ b/drivers/pwm/pwm-tegra.c @@ -239,9 +239,20 @@ static int __devexit tegra_pwm_remove(struct platform_device *pdev) return 0; } +#ifdef CONFIG_OF +static struct of_device_id tegra_pwm_of_match[] = { + { .compatible = "nvidia,tegra20-pwm" }, + { .compatible = "nvidia,tegra30-pwm" }, + { } +}; + +MODULE_DEVICE_TABLE(of, tegra_pwm_of_match); +#endif + static struct platform_driver tegra_pwm_driver = { .driver = { .name = "tegra-pwm", + .of_match_table = of_match_ptr(tegra_pwm_of_match), }, .probe = tegra_pwm_probe, .remove = __devexit_p(tegra_pwm_remove), -- cgit v1.2.3 From 4dce82c1e84007d38747533673c2289bfc6497d2 Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Wed, 4 Apr 2012 10:50:52 +0800 Subject: pwm: add pwm-mxs support Add generic PWM framework driver (DT only) for Freescale MXS. Signed-off-by: Sascha Hauer Signed-off-by: Shawn Guo Signed-off-by: Thierry Reding --- Documentation/devicetree/bindings/pwm/mxs-pwm.txt | 17 ++ drivers/pwm/Kconfig | 9 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-mxs.c | 207 ++++++++++++++++++++++ 4 files changed, 234 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/mxs-pwm.txt create mode 100644 drivers/pwm/pwm-mxs.c (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/pwm/mxs-pwm.txt b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt new file mode 100644 index 000000000000..48ead0db178c --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt @@ -0,0 +1,17 @@ +Freescale MXS PWM controller + +Required properties: +- compatible: should be "fsl,mxs-pwm" +- reg: physical base address and length of the controller's registers +- #pwm-cells: should be 2. The first cell specifies the per-chip index + of the PWM to use and the second cell is the duty cycle in nanoseconds. +- fsl,pwm-number: the number of PWM devices + +Example: + +pwm: pwm@80064000 { + compatible = "fsl,imx28-pwm", "fsl,mxs-pwm"; + reg = <0x80064000 2000>; + #pwm-cells = <2>; + fsl,pwm-number = <8>; +}; diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index a93feffbc36a..39bdebc0cb20 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -27,6 +27,15 @@ config PWM_IMX To compile this driver as a module, choose M here: the module will be called pwm-imx. +config PWM_MXS + tristate "Freescale MXS PWM support" + depends on ARCH_MXS && OF + help + Generic PWM framework driver for Freescale MXS. + + To compile this driver as a module, choose M here: the module + will be called pwm-mxs. + config PWM_PXA tristate "PXA PWM support" depends on ARCH_PXA diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index b7c0fcf4de16..cec250091cff 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -1,6 +1,7 @@ obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o obj-$(CONFIG_PWM_IMX) += pwm-imx.o +obj-$(CONFIG_PWM_MXS) += pwm-mxs.o obj-$(CONFIG_PWM_PXA) += pwm-pxa.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c new file mode 100644 index 000000000000..9602708372b8 --- /dev/null +++ b/drivers/pwm/pwm-mxs.c @@ -0,0 +1,207 @@ +/* + * Copyright 2012 Freescale Semiconductor, Inc. + * + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SET 0x4 +#define CLR 0x8 +#define TOG 0xc + +#define PWM_CTRL 0x0 +#define PWM_ACTIVE0 0x10 +#define PWM_PERIOD0 0x20 +#define PERIOD_PERIOD(p) ((p) & 0xffff) +#define PERIOD_PERIOD_MAX 0x10000 +#define PERIOD_ACTIVE_HIGH (3 << 16) +#define PERIOD_INACTIVE_LOW (2 << 18) +#define PERIOD_CDIV(div) (((div) & 0x7) << 20) +#define PERIOD_CDIV_MAX 8 + +struct mxs_pwm_chip { + struct pwm_chip chip; + struct device *dev; + struct clk *clk; + void __iomem *base; +}; + +#define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip) + +static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); + int ret, div = 0; + unsigned int period_cycles, duty_cycles; + unsigned long rate; + unsigned long long c; + + rate = clk_get_rate(mxs->clk); + while (1) { + c = rate / (1 << div); + c = c * period_ns; + do_div(c, 1000000000); + if (c < PERIOD_PERIOD_MAX) + break; + div++; + if (div > PERIOD_CDIV_MAX) + return -EINVAL; + } + + period_cycles = c; + c *= duty_ns; + do_div(c, period_ns); + duty_cycles = c; + + /* + * If the PWM channel is disabled, make sure to turn on the clock + * before writing the register. Otherwise, keep it enabled. + */ + if (!test_bit(PWMF_ENABLED, &pwm->flags)) { + ret = clk_prepare_enable(mxs->clk); + if (ret) + return ret; + } + + writel(duty_cycles << 16, + mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20); + writel(PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH | + PERIOD_INACTIVE_LOW | PERIOD_CDIV(div), + mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20); + + /* + * If the PWM is not enabled, turn the clock off again to save power. + */ + if (!test_bit(PWMF_ENABLED, &pwm->flags)) + clk_disable_unprepare(mxs->clk); + + return 0; +} + +static int mxs_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); + int ret; + + ret = clk_prepare_enable(mxs->clk); + if (ret) + return ret; + + writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET); + + return 0; +} + +static void mxs_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); + + writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR); + + clk_disable_unprepare(mxs->clk); +} + +static const struct pwm_ops mxs_pwm_ops = { + .config = mxs_pwm_config, + .enable = mxs_pwm_enable, + .disable = mxs_pwm_disable, + .owner = THIS_MODULE, +}; + +static int mxs_pwm_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct mxs_pwm_chip *mxs; + int ret; + + mxs = devm_kzalloc(&pdev->dev, sizeof(*mxs), GFP_KERNEL); + if (!mxs) + return -ENOMEM; + + mxs->base = of_iomap(np, 0); + if (!mxs->base) + return -EADDRNOTAVAIL; + + mxs->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(mxs->clk)) { + ret = PTR_ERR(mxs->clk); + goto iounmap; + } + + mxs->chip.dev = &pdev->dev; + mxs->chip.ops = &mxs_pwm_ops; + mxs->chip.base = -1; + ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); + goto clk_put; + } + + ret = pwmchip_add(&mxs->chip); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret); + goto clk_put; + } + + mxs->dev = &pdev->dev; + platform_set_drvdata(pdev, mxs); + + mxs_reset_block(mxs->base); + + return 0; + +clk_put: + clk_put(mxs->clk); +iounmap: + iounmap(mxs->base); + return ret; +} + +static int __devexit mxs_pwm_remove(struct platform_device *pdev) +{ + struct mxs_pwm_chip *mxs = platform_get_drvdata(pdev); + + pwmchip_remove(&mxs->chip); + clk_put(mxs->clk); + iounmap(mxs->base); + + return 0; +} + +static struct of_device_id mxs_pwm_dt_ids[] = { + { .compatible = "fsl,mxs-pwm", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mxs_pwm_dt_ids); + +static struct platform_driver mxs_pwm_driver = { + .driver = { + .name = "mxs-pwm", + .of_match_table = of_match_ptr(mxs_pwm_dt_ids), + }, + .probe = mxs_pwm_probe, + .remove = __devexit_p(mxs_pwm_remove), +}; +module_platform_driver(mxs_pwm_driver); + +MODULE_ALIAS("platform:mxs-pwm"); +MODULE_AUTHOR("Shawn Guo "); +MODULE_DESCRIPTION("Freescale MXS PWM Driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3 From 3e3ed6cdc49d758719c148a78c8b04c243ef74d0 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Fri, 16 Dec 2011 21:25:29 +0100 Subject: pwm-backlight: Add rudimentary device tree support This commit adds very basic support for device tree probing. Currently, only a PWM and a list of distinct brightness levels can be specified. Enabling or disabling backlight power via GPIOs is not yet supported. Reviewed-by: Shawn Guo Reviewed-by: Mark Brown Signed-off-by: Thierry Reding --- .../bindings/video/backlight/pwm-backlight.txt | 28 ++++ drivers/video/backlight/Kconfig | 2 +- drivers/video/backlight/pwm_bl.c | 149 ++++++++++++++++++--- include/linux/pwm_backlight.h | 1 + 4 files changed, 159 insertions(+), 21 deletions(-) create mode 100644 Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt new file mode 100644 index 000000000000..1e4fc727f3b1 --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt @@ -0,0 +1,28 @@ +pwm-backlight bindings + +Required properties: + - compatible: "pwm-backlight" + - pwms: OF device-tree PWM specification (see PWM binding[0]) + - brightness-levels: Array of distinct brightness levels. Typically these + are in the range from 0 to 255, but any range starting at 0 will do. + The actual brightness level (PWM duty cycle) will be interpolated + from these values. 0 means a 0% duty cycle (darkest/off), while the + last value in the array represents a 100% duty cycle (brightest). + - default-brightness-level: the default brightness level (index into the + array defined by the "brightness-levels" property) + +Optional properties: + - pwm-names: a list of names for the PWM devices specified in the + "pwms" property (see PWM binding[0]) + +[0]: Documentation/devicetree/bindings/pwm/pwm.txt + +Example: + + backlight { + compatible = "pwm-backlight"; + pwms = <&pwm 0 5000000>; + + brightness-levels = <0 4 8 16 32 64 128 255>; + default-brightness-level = <6>; + }; diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index fa2b03750316..4c9c02216351 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -245,7 +245,7 @@ config BACKLIGHT_CARILLO_RANCH config BACKLIGHT_PWM tristate "Generic PWM based Backlight Driver" - depends on HAVE_PWM + depends on PWM help If you have a LCD backlight adjustable by PWM, say Y to enable this driver. diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 342b7d7cbb63..057389d69a51 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -26,11 +26,13 @@ struct pwm_bl_data { struct device *dev; unsigned int period; unsigned int lth_brightness; + unsigned int *levels; int (*notify)(struct device *, int brightness); void (*notify_after)(struct device *, int brightness); int (*check_fb)(struct device *, struct fb_info *); + void (*exit)(struct device *); }; static int pwm_backlight_update_status(struct backlight_device *bl) @@ -52,6 +54,11 @@ static int pwm_backlight_update_status(struct backlight_device *bl) pwm_config(pb->pwm, 0, pb->period); pwm_disable(pb->pwm); } else { + if (pb->levels) { + brightness = pb->levels[brightness]; + max = pb->levels[max]; + } + brightness = pb->lth_brightness + (brightness * (pb->period - pb->lth_brightness) / max); pwm_config(pb->pwm, brightness, pb->period); @@ -83,17 +90,98 @@ static const struct backlight_ops pwm_backlight_ops = { .check_fb = pwm_backlight_check_fb, }; +#ifdef CONFIG_OF +static int pwm_backlight_parse_dt(struct device *dev, + struct platform_pwm_backlight_data *data) +{ + struct device_node *node = dev->of_node; + struct property *prop; + int length; + u32 value; + int ret; + + if (!node) + return -ENODEV; + + memset(data, 0, sizeof(*data)); + + /* determine the number of brightness levels */ + prop = of_find_property(node, "brightness-levels", &length); + if (!prop) + return -EINVAL; + + data->max_brightness = length / sizeof(u32); + + /* read brightness levels from DT property */ + if (data->max_brightness > 0) { + size_t size = sizeof(*data->levels) * data->max_brightness; + + data->levels = devm_kzalloc(dev, size, GFP_KERNEL); + if (!data->levels) + return -ENOMEM; + + ret = of_property_read_u32_array(node, "brightness-levels", + data->levels, + data->max_brightness); + if (ret < 0) + return ret; + + ret = of_property_read_u32(node, "default-brightness-level", + &value); + if (ret < 0) + return ret; + + if (value >= data->max_brightness) { + dev_warn(dev, "invalid default brightness level: %u, using %u\n", + value, data->max_brightness - 1); + value = data->max_brightness - 1; + } + + data->dft_brightness = value; + data->max_brightness--; + } + + /* + * TODO: Most users of this driver use a number of GPIOs to control + * backlight power. Support for specifying these needs to be + * added. + */ + + return 0; +} + +static struct of_device_id pwm_backlight_of_match[] = { + { .compatible = "pwm-backlight" }, + { } +}; + +MODULE_DEVICE_TABLE(of, pwm_backlight_of_match); +#else +static int pwm_backlight_parse_dt(struct device *dev, + struct platform_pwm_backlight_data *data) +{ + return -ENODEV; +} +#endif + static int pwm_backlight_probe(struct platform_device *pdev) { - struct backlight_properties props; struct platform_pwm_backlight_data *data = pdev->dev.platform_data; + struct platform_pwm_backlight_data defdata; + struct backlight_properties props; struct backlight_device *bl; struct pwm_bl_data *pb; + unsigned int max; int ret; if (!data) { - dev_err(&pdev->dev, "failed to find platform data\n"); - return -EINVAL; + ret = pwm_backlight_parse_dt(&pdev->dev, &defdata); + if (ret < 0) { + dev_err(&pdev->dev, "failed to find platform data\n"); + return ret; + } + + data = &defdata; } if (data->init) { @@ -109,21 +197,42 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } - pb->period = data->pwm_period_ns; + if (data->levels) { + max = data->levels[data->max_brightness]; + pb->levels = data->levels; + } else + max = data->max_brightness; + pb->notify = data->notify; pb->notify_after = data->notify_after; pb->check_fb = data->check_fb; - pb->lth_brightness = data->lth_brightness * - (data->pwm_period_ns / data->max_brightness); + pb->exit = data->exit; pb->dev = &pdev->dev; - pb->pwm = pwm_request(data->pwm_id, "backlight"); + pb->pwm = pwm_get(&pdev->dev, NULL); if (IS_ERR(pb->pwm)) { - dev_err(&pdev->dev, "unable to request PWM for backlight\n"); - ret = PTR_ERR(pb->pwm); - goto err_alloc; - } else - dev_dbg(&pdev->dev, "got pwm for backlight\n"); + dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); + + pb->pwm = pwm_request(data->pwm_id, "pwm-backlight"); + if (IS_ERR(pb->pwm)) { + dev_err(&pdev->dev, "unable to request legacy PWM\n"); + ret = PTR_ERR(pb->pwm); + goto err_alloc; + } + } + + dev_dbg(&pdev->dev, "got pwm for backlight\n"); + + /* + * The DT case will set the pwm_period_ns field to 0 and store the + * period, parsed from the DT, in the PWM device. For the non-DT case, + * set the period from platform data. + */ + if (data->pwm_period_ns > 0) + pwm_set_period(pb->pwm, data->pwm_period_ns); + + pb->period = pwm_get_period(pb->pwm); + pb->lth_brightness = data->lth_brightness * (pb->period / max); memset(&props, 0, sizeof(struct backlight_properties)); props.type = BACKLIGHT_RAW; @@ -143,7 +252,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) return 0; err_bl: - pwm_free(pb->pwm); + pwm_put(pb->pwm); err_alloc: if (data->exit) data->exit(&pdev->dev); @@ -152,16 +261,15 @@ err_alloc: static int pwm_backlight_remove(struct platform_device *pdev) { - struct platform_pwm_backlight_data *data = pdev->dev.platform_data; struct backlight_device *bl = platform_get_drvdata(pdev); struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); backlight_device_unregister(bl); pwm_config(pb->pwm, 0, pb->period); pwm_disable(pb->pwm); - pwm_free(pb->pwm); - if (data->exit) - data->exit(&pdev->dev); + pwm_put(pb->pwm); + if (pb->exit) + pb->exit(&pdev->dev); return 0; } @@ -195,11 +303,12 @@ static SIMPLE_DEV_PM_OPS(pwm_backlight_pm_ops, pwm_backlight_suspend, static struct platform_driver pwm_backlight_driver = { .driver = { - .name = "pwm-backlight", - .owner = THIS_MODULE, + .name = "pwm-backlight", + .owner = THIS_MODULE, #ifdef CONFIG_PM - .pm = &pwm_backlight_pm_ops, + .pm = &pwm_backlight_pm_ops, #endif + .of_match_table = of_match_ptr(pwm_backlight_of_match), }, .probe = pwm_backlight_probe, .remove = pwm_backlight_remove, diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h index 63d2df43e61a..56f4a866539a 100644 --- a/include/linux/pwm_backlight.h +++ b/include/linux/pwm_backlight.h @@ -12,6 +12,7 @@ struct platform_pwm_backlight_data { unsigned int dft_brightness; unsigned int lth_brightness; unsigned int pwm_period_ns; + unsigned int *levels; int (*init)(struct device *dev); int (*notify)(struct device *dev, int brightness); void (*notify_after)(struct device *dev, int brightness); -- cgit v1.2.3 From 071407eefd708d7e273b67af150f8dff6c51eb58 Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Tue, 26 Jun 2012 16:58:08 +0800 Subject: pwm: pwm-mxs: encode soc name in compatible string Encode soc name in the compatible string to know the specific version hardware block. This is the general approach adopted for most bindings. Change mxs-pwm binding to use the approach. Signed-off-by: Shawn Guo Signed-off-by: Thierry Reding --- Documentation/devicetree/bindings/pwm/mxs-pwm.txt | 4 ++-- drivers/pwm/pwm-mxs.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/pwm/mxs-pwm.txt b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt index 48ead0db178c..b16f4a57d111 100644 --- a/Documentation/devicetree/bindings/pwm/mxs-pwm.txt +++ b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt @@ -1,7 +1,7 @@ Freescale MXS PWM controller Required properties: -- compatible: should be "fsl,mxs-pwm" +- compatible: should be "fsl,imx23-pwm" - reg: physical base address and length of the controller's registers - #pwm-cells: should be 2. The first cell specifies the per-chip index of the PWM to use and the second cell is the duty cycle in nanoseconds. @@ -10,7 +10,7 @@ Required properties: Example: pwm: pwm@80064000 { - compatible = "fsl,imx28-pwm", "fsl,mxs-pwm"; + compatible = "fsl,imx28-pwm", "fsl,imx23-pwm"; reg = <0x80064000 2000>; #pwm-cells = <2>; fsl,pwm-number = <8>; diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c index 9602708372b8..d9a38050a502 100644 --- a/drivers/pwm/pwm-mxs.c +++ b/drivers/pwm/pwm-mxs.c @@ -186,7 +186,7 @@ static int __devexit mxs_pwm_remove(struct platform_device *pdev) } static struct of_device_id mxs_pwm_dt_ids[] = { - { .compatible = "fsl,mxs-pwm", }, + { .compatible = "fsl,imx23-pwm", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, mxs_pwm_dt_ids); -- cgit v1.2.3 From 2132fa8d95bc13b8b0e307553b04ee3517762ebe Mon Sep 17 00:00:00 2001 From: Alexandre Pereira da Silva Date: Tue, 10 Jul 2012 11:38:10 -0300 Subject: pwm: add lpc32xx PWM support Add lpc32xx SOC PWM driver. Signed-off-by: Alexandre Pereira da Silva Acked-by: Roland Stigge Signed-off-by: Thierry Reding --- .../devicetree/bindings/pwm/lpc32xx-pwm.txt | 12 ++ drivers/pwm/Kconfig | 10 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-lpc32xx.c | 148 +++++++++++++++++++++ 4 files changed, 171 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt create mode 100644 drivers/pwm/pwm-lpc32xx.c (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt b/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt new file mode 100644 index 000000000000..cfe1db3bb6e9 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt @@ -0,0 +1,12 @@ +LPC32XX PWM controller + +Required properties: +- compatible: should be "nxp,lpc3220-pwm" +- reg: physical base address and length of the controller's registers + +Examples: + +pwm@0x4005C000 { + compatible = "nxp,lpc3220-pwm"; + reg = <0x4005C000 0x8>; +}; diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 0b2800fc1ca7..94e176e26f4c 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -28,6 +28,16 @@ config PWM_IMX To compile this driver as a module, choose M here: the module will be called pwm-imx. +config PWM_LPC32XX + tristate "LPC32XX PWM support" + depends on ARCH_LPC32XX + help + Generic PWM framework driver for LPC32XX. The LPC32XX SOC has two + PWM controllers. + + To compile this driver as a module, choose M here: the module + will be called pwm-lpc32xx. + config PWM_MXS tristate "Freescale MXS PWM support" depends on ARCH_MXS && OF diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index cec250091cff..54597020350f 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -1,6 +1,7 @@ obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o obj-$(CONFIG_PWM_IMX) += pwm-imx.o +obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o obj-$(CONFIG_PWM_MXS) += pwm-mxs.o obj-$(CONFIG_PWM_PXA) += pwm-pxa.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c new file mode 100644 index 000000000000..adb87f0c1633 --- /dev/null +++ b/drivers/pwm/pwm-lpc32xx.c @@ -0,0 +1,148 @@ +/* + * Copyright 2012 Alexandre Pereira da Silva + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct lpc32xx_pwm_chip { + struct pwm_chip chip; + struct clk *clk; + void __iomem *base; +}; + +#define PWM_ENABLE (1 << 31) +#define PWM_RELOADV(x) (((x) & 0xFF) << 8) +#define PWM_DUTY(x) ((x) & 0xFF) + +#define to_lpc32xx_pwm_chip(_chip) \ + container_of(_chip, struct lpc32xx_pwm_chip, chip) + +static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); + unsigned long long c; + int period_cycles, duty_cycles; + + c = clk_get_rate(lpc32xx->clk) / 256; + c = c * period_ns; + do_div(c, NSEC_PER_SEC); + + /* Handle high and low extremes */ + if (c == 0) + c = 1; + if (c > 255) + c = 0; /* 0 set division by 256 */ + period_cycles = c; + + c = 256 * duty_ns; + do_div(c, period_ns); + duty_cycles = c; + + writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles), + lpc32xx->base + (pwm->hwpwm << 2)); + + return 0; +} + +static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); + + return clk_enable(lpc32xx->clk); +} + +static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); + + writel(0, lpc32xx->base + (pwm->hwpwm << 2)); + clk_disable(lpc32xx->clk); +} + +static const struct pwm_ops lpc32xx_pwm_ops = { + .config = lpc32xx_pwm_config, + .enable = lpc32xx_pwm_enable, + .disable = lpc32xx_pwm_disable, + .owner = THIS_MODULE, +}; + +static int lpc32xx_pwm_probe(struct platform_device *pdev) +{ + struct lpc32xx_pwm_chip *lpc32xx; + struct resource *res; + int ret; + + lpc32xx = devm_kzalloc(&pdev->dev, sizeof(*lpc32xx), GFP_KERNEL); + if (!lpc32xx) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -EINVAL; + + lpc32xx->base = devm_request_and_ioremap(&pdev->dev, res); + if (!lpc32xx->base) + return -EADDRNOTAVAIL; + + lpc32xx->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(lpc32xx->clk)) + return PTR_ERR(lpc32xx->clk); + + lpc32xx->chip.dev = &pdev->dev; + lpc32xx->chip.ops = &lpc32xx_pwm_ops; + lpc32xx->chip.npwm = 2; + + ret = pwmchip_add(&lpc32xx->chip); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret); + return ret; + } + + platform_set_drvdata(pdev, lpc32xx); + + return 0; +} + +static int __devexit lpc32xx_pwm_remove(struct platform_device *pdev) +{ + struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev); + + clk_disable(lpc32xx->clk); + return pwmchip_remove(&lpc32xx->chip); +} + +static struct of_device_id lpc32xx_pwm_dt_ids[] = { + { .compatible = "nxp,lpc3220-pwm", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids); + +static struct platform_driver lpc32xx_pwm_driver = { + .driver = { + .name = "lpc32xx-pwm", + .of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids), + }, + .probe = lpc32xx_pwm_probe, + .remove = __devexit_p(lpc32xx_pwm_remove), +}; +module_platform_driver(lpc32xx_pwm_driver); + +MODULE_ALIAS("platform:lpc32xx-pwm"); +MODULE_AUTHOR("Alexandre Pereira da Silva "); +MODULE_DESCRIPTION("LPC32XX PWM Driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3