diff options
Diffstat (limited to 'drivers/pwm/pwm-mediatek.c')
| -rw-r--r-- | drivers/pwm/pwm-mediatek.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c new file mode 100644 index 000000000..eb6674ce9 --- /dev/null +++ b/drivers/pwm/pwm-mediatek.c @@ -0,0 +1,325 @@ +/* + * Mediatek Pulse Width Modulator driver + * + * Copyright (C) 2015 John Crispin <blogic@openwrt.org> + * Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com> + * + * 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 <linux/err.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/clk.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/slab.h> +#include <linux/types.h> + +/* PWM registers and bits definitions */ +#define PWMCON 0x00 +#define PWMHDUR 0x04 +#define PWMLDUR 0x08 +#define PWMGDUR 0x0c +#define PWMWAVENUM 0x28 +#define PWMDWIDTH 0x2c +#define PWM45DWIDTH_FIXUP 0x30 +#define PWMTHRES 0x30 +#define PWM45THRES_FIXUP 0x34 + +#define PWM_CLK_DIV_MAX 7 + +enum { + MTK_CLK_MAIN = 0, + MTK_CLK_TOP, + MTK_CLK_PWM1, + MTK_CLK_PWM2, + MTK_CLK_PWM3, + MTK_CLK_PWM4, + MTK_CLK_PWM5, + MTK_CLK_PWM6, + MTK_CLK_PWM7, + MTK_CLK_PWM8, + MTK_CLK_MAX, +}; + +static const char * const mtk_pwm_clk_name[MTK_CLK_MAX] = { + "main", "top", "pwm1", "pwm2", "pwm3", "pwm4", "pwm5", "pwm6", "pwm7", + "pwm8" +}; + +struct mtk_pwm_platform_data { + unsigned int num_pwms; + bool pwm45_fixup; + bool has_clks; +}; + +/** + * struct mtk_pwm_chip - struct representing PWM chip + * @chip: linux PWM chip representation + * @regs: base address of PWM chip + * @clks: list of clocks + */ +struct mtk_pwm_chip { + struct pwm_chip chip; + void __iomem *regs; + struct clk *clks[MTK_CLK_MAX]; + const struct mtk_pwm_platform_data *soc; +}; + +static const unsigned int mtk_pwm_reg_offset[] = { + 0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220 +}; + +static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct mtk_pwm_chip, chip); +} + +static int mtk_pwm_clk_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); + int ret; + + if (!pc->soc->has_clks) + return 0; + + ret = clk_prepare_enable(pc->clks[MTK_CLK_TOP]); + if (ret < 0) + return ret; + + ret = clk_prepare_enable(pc->clks[MTK_CLK_MAIN]); + if (ret < 0) + goto disable_clk_top; + + ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); + if (ret < 0) + goto disable_clk_main; + + return 0; + +disable_clk_main: + clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]); +disable_clk_top: + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); + + return ret; +} + +static void mtk_pwm_clk_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); + + if (!pc->soc->has_clks) + return; + + clk_disable_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); + clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]); + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); +} + +static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num, + unsigned int offset) +{ + return readl(chip->regs + mtk_pwm_reg_offset[num] + offset); +} + +static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip, + unsigned int num, unsigned int offset, + u32 value) +{ + writel(value, chip->regs + mtk_pwm_reg_offset[num] + 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); + struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]; + u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH, + reg_thres = PWMTHRES; + u64 resolution; + int ret; + + ret = mtk_pwm_clk_enable(chip, pwm); + if (ret < 0) + return ret; + + /* Using resolution in picosecond gets accuracy higher */ + resolution = (u64)NSEC_PER_SEC * 1000; + do_div(resolution, clk_get_rate(clk)); + + cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution); + while (cnt_period > 8191) { + resolution *= 2; + clkdiv++; + cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, + resolution); + } + + if (clkdiv > PWM_CLK_DIV_MAX) { + mtk_pwm_clk_disable(chip, pwm); + dev_err(chip->dev, "period %d not supported\n", period_ns); + return -EINVAL; + } + + if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) { + /* + * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES + * from the other PWMs on MT7623. + */ + reg_width = PWM45DWIDTH_FIXUP; + reg_thres = PWM45THRES_FIXUP; + } + + cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution); + mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv); + mtk_pwm_writel(pc, pwm->hwpwm, reg_width, cnt_period); + mtk_pwm_writel(pc, pwm->hwpwm, reg_thres, cnt_duty); + + mtk_pwm_clk_disable(chip, pwm); + + return 0; +} + +static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); + u32 value; + int ret; + + ret = mtk_pwm_clk_enable(chip, pwm); + if (ret < 0) + return ret; + + value = readl(pc->regs); + value |= BIT(pwm->hwpwm); + writel(value, pc->regs); + + 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 value; + + value = readl(pc->regs); + value &= ~BIT(pwm->hwpwm); + writel(value, pc->regs); + + mtk_pwm_clk_disable(chip, pwm); +} + +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) +{ + const struct mtk_pwm_platform_data *data; + struct mtk_pwm_chip *pc; + struct resource *res; + unsigned int i; + int ret; + + pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); + if (!pc) + return -ENOMEM; + + data = of_device_get_match_data(&pdev->dev); + if (data == NULL) + return -EINVAL; + pc->soc = data; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pc->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(pc->regs)) + return PTR_ERR(pc->regs); + + for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { + pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); + if (IS_ERR(pc->clks[i])) { + dev_err(&pdev->dev, "clock: %s fail: %ld\n", + mtk_pwm_clk_name[i], PTR_ERR(pc->clks[i])); + return PTR_ERR(pc->clks[i]); + } + } + + platform_set_drvdata(pdev, pc); + + pc->chip.dev = &pdev->dev; + pc->chip.ops = &mtk_pwm_ops; + pc->chip.base = -1; + pc->chip.npwm = data->num_pwms; + + ret = pwmchip_add(&pc->chip); + if (ret < 0) { + dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); + return ret; + } + + return 0; +} + +static int mtk_pwm_remove(struct platform_device *pdev) +{ + struct mtk_pwm_chip *pc = platform_get_drvdata(pdev); + + return pwmchip_remove(&pc->chip); +} + +static const struct mtk_pwm_platform_data mt2712_pwm_data = { + .num_pwms = 8, + .pwm45_fixup = false, + .has_clks = true, +}; + +static const struct mtk_pwm_platform_data mt7622_pwm_data = { + .num_pwms = 6, + .pwm45_fixup = false, + .has_clks = true, +}; + +static const struct mtk_pwm_platform_data mt7623_pwm_data = { + .num_pwms = 5, + .pwm45_fixup = true, + .has_clks = true, +}; + +static const struct mtk_pwm_platform_data mt7628_pwm_data = { + .num_pwms = 4, + .pwm45_fixup = true, + .has_clks = false, +}; + +static const struct of_device_id mtk_pwm_of_match[] = { + { .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data }, + { .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data }, + { .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data }, + { .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data }, + { }, +}; +MODULE_DEVICE_TABLE(of, mtk_pwm_of_match); + +static struct platform_driver mtk_pwm_driver = { + .driver = { + .name = "mtk-pwm", + .of_match_table = mtk_pwm_of_match, + }, + .probe = mtk_pwm_probe, + .remove = mtk_pwm_remove, +}; +module_platform_driver(mtk_pwm_driver); + +MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); +MODULE_LICENSE("GPL"); |