From fc8f96309c21c1bc3276427309cd7d361347d66e Mon Sep 17 00:00:00 2001 From: John Crispin Date: Mon, 7 Dec 2015 17:16:50 +0100 Subject: [PATCH 52/53] pwm: add mediatek support Signed-off-by: John Crispin --- drivers/pwm/Kconfig | 9 +++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-mediatek.c | 173 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 183 insertions(+) create mode 100644 drivers/pwm/pwm-mediatek.c --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -302,6 +302,15 @@ config PWM_MEDIATEK To compile this driver as a module, choose M here: the module will be called pwm-mediatek. +config PWM_MEDIATEK_RAMIPS + tristate "Mediatek PWM support" + depends on RALINK && OF + help + Generic PWM framework driver for Mediatek ARM SoC. + + To compile this driver as a module, choose M here: the module + will be called pwm-mxs. + config PWM_MXS tristate "Freescale MXS PWM support" depends on ARCH_MXS && OF --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_PWM_LPSS_PCI) += pwm-lpss-p obj-$(CONFIG_PWM_LPSS_PLATFORM) += pwm-lpss-platform.o obj-$(CONFIG_PWM_MESON) += pwm-meson.o obj-$(CONFIG_PWM_MEDIATEK) += pwm-mediatek.o +obj-$(CONFIG_PWM_MEDIATEK_RAMIPS) += pwm-mediatek-ramips.o obj-$(CONFIG_PWM_MTK_DISP) += pwm-mtk-disp.o obj-$(CONFIG_PWM_MXS) += pwm-mxs.o obj-$(CONFIG_PWM_OMAP_DMTIMER) += pwm-omap-dmtimer.o --- /dev/null +++ b/drivers/pwm/pwm-mediatek-ramips.c @@ -0,0 +1,173 @@ +/* + * Mediatek Pulse Width Modulator driver + * + * Copyright (C) 2015 John Crispin + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define NUM_PWM 4 + +/* PWM registers and bits definitions */ +#define PWMCON 0x00 +#define PWMHDUR 0x04 +#define PWMLDUR 0x08 +#define PWMGDUR 0x0c +#define PWMWAVENUM 0x28 +#define PWMDWIDTH 0x2c +#define PWMTHRES 0x30 + +/** + * struct mtk_pwm_chip - struct representing pwm chip + * + * @mmio_base: base address of pwm chip + * @chip: linux pwm chip representation + */ +struct mtk_pwm_chip { + void __iomem *mmio_base; + struct pwm_chip chip; +}; + +static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct mtk_pwm_chip, chip); +} + +static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num, + unsigned long offset) +{ + return ioread32(chip->mmio_base + 0x10 + (num * 0x40) + offset); +} + +static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip, + unsigned int num, unsigned long offset, + unsigned long val) +{ + iowrite32(val, chip->mmio_base + 0x10 + (num * 0x40) + offset); +} + +static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); + u32 resolution = 100 / 4; + u32 clkdiv = 0; + + while (period_ns / resolution > 8191) { + clkdiv++; + resolution *= 2; + } + + if (clkdiv > 7) + return -1; + + mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | BIT(3) | clkdiv); + mtk_pwm_writel(pc, pwm->hwpwm, PWMDWIDTH, period_ns / resolution); + mtk_pwm_writel(pc, pwm->hwpwm, PWMTHRES, duty_ns / resolution); + r
generated by cgit v1.2.3 (git 2.25.1) at hwpwm); + iowrite32(val, pc->mmio_base); + + return 0; +} + +static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); + u32 val; + + val = ioread32(pc->mmio_base); + val &= ~BIT(pwm->hwpwm); + iowrite32(val, pc->mmio_base); +} + +static const struct pwm_ops mtk_pwm_ops = { + .config = mtk_pwm_config, + .enable = mtk_pwm_enable, + .disable = mtk_pwm_disable, + .owner = THIS_MODULE, +}; + +static int mtk_pwm_probe(struct platform_device *pdev) +{ + struct mtk_pwm_chip *pc; + struct resource *r; + int ret; + + pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); + if (!pc) + return -ENOMEM; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pc->mmio_base = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(pc->mmio_base)) + return PTR_ERR(pc->mmio_base); + + platform_set_drvdata(pdev, pc); + + pc->chip.dev = &pdev->dev; + pc->chip.ops = &mtk_pwm_ops; + pc->chip.base = -1; + pc->chip.npwm = NUM_PWM; + + ret = pwmchip_add(&pc->chip); + if (ret < 0) + dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); + + return ret; +} + +static int mtk_pwm_remove(struct platform_device *pdev) +{ + struct mtk_pwm_chip *pc = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < NUM_PWM; i++) + pwm_disable(&pc->chip.pwms[i]); + + return pwmchip_remove(&pc->chip); +} + +static const struct of_device_id mtk_pwm_of_match[] = { + { .compatible = "mediatek,mt7628-pwm" }, + { } +}; + +MODULE_DEVICE_TABLE(of, mtk_pwm_of_match); + +static struct platform_driver mtk_pwm_driver = { + .driver = { + .name = "mtk-pwm", + .owner = THIS_MODULE, + .of_match_table = mtk_pwm_of_match, + }, + .probe = mtk_pwm_probe, + .remove = mtk_pwm_remove, +}; + +module_platform_driver(mtk_pwm_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("John Crispin "); +MODULE_ALIAS("platform:mtk-pwm");