diff options
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt | 12 | ||||
| -rw-r--r-- | drivers/pwm/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/pwm/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pwm/pwm-lpc32xx.c | 148 |
4 files changed, 171 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt b/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt new file mode 100644 index 00000000000..cfe1db3bb6e --- /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 0b2800fc1ca..94e176e26f4 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 cec250091cf..54597020350 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 00000000000..adb87f0c163 --- /dev/null +++ b/drivers/pwm/pwm-lpc32xx.c @@ -0,0 +1,148 @@ +/* + * Copyright 2012 Alexandre Pereira da Silva <aletes.xgr@gmail.com> + * + * 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 <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/slab.h> + +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 <aletes.xgr@gmail.com>"); +MODULE_DESCRIPTION("LPC32XX PWM Driver"); +MODULE_LICENSE("GPL v2"); |