From 77e664940f6daa86965d16a2047188519341a31a Mon Sep 17 00:00:00 2001 From: YH Huang Date: Mon, 11 May 2015 17:26:22 +0800 Subject: [PATCH 28/76] pwm: add Mediatek display PWM driver support Add display PWM driver support to modify backlight for MT8173/MT6595. Signed-off-by: YH Huang --- drivers/pwm/Kconfig | 9 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-disp-mediatek.c | 225 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 235 insertions(+) create mode 100644 drivers/pwm/pwm-disp-mediatek.c --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -111,6 +111,15 @@ config PWM_CLPS711X To compile this driver as a module, choose M here: the module will be called pwm-clps711x. +config PWM_DISP_MEDIATEK + tristate "MEDIATEK display PWM driver" + depends on OF + help + Generic PWM framework driver for mediatek disp-pwm device. + + To compile this driver as a module, choose M here: the module + will be called pwm-disp-mediatek. + config PWM_EP93XX tristate "Cirrus Logic EP93xx PWM support" depends on ARCH_EP93XX --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_PWM_BCM_KONA) += pwm-bcm-ko obj-$(CONFIG_PWM_BCM2835) += pwm-bcm2835.o obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o +obj-$(CONFIG_PWM_DISP_MEDIATEK) += pwm-disp-mediatek.o obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o obj-$(CONFIG_PWM_IMG) += pwm-img.o --- /dev/null +++ b/drivers/pwm/pwm-disp-mediatek.c @@ -0,0 +1,225 @@ +/* + * Mediatek display pulse-width-modulation controller driver. + * Copyright (c) 2015 MediaTek Inc. + * Author: YH Huang + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define DISP_PWM_EN_OFF (0x0) +#define PWM_ENABLE_SHIFT (0x0) +#define PWM_ENABLE_MASK (0x1 << PWM_ENABLE_SHIFT) + +#define DISP_PWM_COMMIT_OFF (0x08) +#define PWM_COMMIT_SHIFT (0x0) +#define PWM_COMMIT_MASK (0x1 << PWM_COMMIT_SHIFT) + +#define DISP_PWM_CON_0_OFF (0x10) +#define PWM_CLKDIV_SHIFT (0x10) +#define PWM_CLKDIV_MASK (0x3ff << PWM_CLKDIV_SHIFT) +#define PWM_CLKDIV_MAX (0x000003ff) + +#define DISP_PWM_CON_1_OFF (0x14) +#define PWM_PERIOD_SHIFT (0x0) +#define PWM_PERIOD_MASK (0xfff << PWM_PERIOD_SHIFT) +#define PWM_PERIOD_MAX (0x00000fff) +/* Shift log2(PWM_PERIOD_MAX + 1) as divisor */ +#define PWM_PERIOD_BIT_SHIFT 12 + +#define PWM_HIGH_WIDTH_SHIFT (0x10) +#define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT) + +#define NUM_PWM 1 + +struct mtk_disp_pwm_chip { + struct pwm_chip chip; + struct device *dev; + struct clk *clk_main; + struct clk *clk_mm; + void __iomem *mmio_base; +}; + +static void mtk_disp_pwm_setting(void __iomem *address, u32 value, u32 mask) +{ + u32 val; + + val = readl(address); + val &= ~mask; + val |= value; + writel(val, address); +} + +static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct mtk_disp_pwm_chip *mpc; + u64 div, rate; + u32 clk_div, period, high_width, rem; + + /* + * Find period, high_width and clk_div to suit duty_ns and period_ns. + * Calculate proper div value to keep period value in the bound. + * + * period_ns = 10^9 * (clk_div + 1) * (period +1) / PWM_CLK_RATE + * duty_ns = 10^9 * (clk_div + 1) * (high_width + 1) / PWM_CLK_RATE + * + * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1 + * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1)) - 1 + */ + mpc = container_of(chip, struct mtk_disp_pwm_chip, chip); + rate = clk_get_rate(mpc->clk_main); + clk_div = div_u64_rem(rate * period_ns, NSEC_PER_SEC, &rem) >> + PWM_PERIOD_BIT_SHIFT; + if (clk_div > PWM_CLKDIV_MAX) + return -EINVAL; + + div = clk_div + 1; + period = div64_u64(rate * period_ns, NSEC_PER_SEC * div); + if (period > 0) + period--; + high_width = div64_u64(rate * duty_ns, NSEC_PER_SEC * div); + if (high_width > 0) + high_width--; + + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_CON_0_OFF, + clk_div << PWM_CLKDIV_SHIFT, PWM_CLKDIV_MASK); + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_CON_1_OFF, + (period << PWM_PERIOD_SHIFT) | + (high_width << PWM_HIGH_WIDTH_SHIFT), + PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK); + + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_COMMIT_OFF, + 1 << PWM_COMMIT_SHIFT, PWM_COMMIT_MASK); + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_COMMIT_OFF, + 0 << PWM_COMMIT_SHIFT, PWM_COMMIT_MASK); + + return 0; +} + +static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_disp_pwm_chip *mpc; + + mpc = container_of(chip, struct mtk_disp_pwm_chip, chip); + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_EN_OFF, + 1 << PWM_ENABLE_SHIFT, PWM_ENABLE_MASK); + + return 0; +} + +static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_disp_pwm_chip *mpc; + + mpc = container_of(chip, struct mtk_disp_pwm_chip, chip); + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_EN_OFF, + 0 << PWM_ENABLE_SHIFT, PWM_ENABLE_MASK); +} + +static const struct pwm_ops mtk_disp_pwm_ops = { + .config = mtk_disp_pwm_config, + .enable = mtk_disp_pwm_enable, + .disable = mtk_disp_pwm_disable, + .owner = THIS_MODULE, +}; + +static int mtk_disp_pwm_probe(struct platform_device *pdev) +{ + struct mtk_disp_pwm_chip *pwm; + struct resource *r; + int ret; + + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); + if (!pwm) + return -ENOMEM; + + pwm->dev = &pdev->dev; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pwm->mmio_base = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(pwm->mmio_base)) + return PTR_ERR(pwm->mmio_base); + + pwm->clk_main = devm_clk_get(&pdev->dev, "main"); + if (IS_ERR(pwm->clk_main)) + return PTR_ERR(pwm->clk_main); + pwm->clk_mm = devm_clk_get(&pdev->dev, "mm"); + if (IS_ERR(pwm->clk_mm)) + return PTR_ERR(pwm->clk_mm); + + ret = clk_prepare_enable(pwm->clk_main); + if (ret < 0) + return ret; + ret = clk_prepare_enable(pwm->clk_mm); + if (ret < 0) { + clk_disable_unprepare(pwm->clk_main); + return ret; + } + + platform_set_drvdata(pdev, pwm); + + pwm->chip.dev = &pdev->dev; + pwm->chip.ops = &mtk_disp_pwm_ops; + pwm->chip.base = -1; + pwm->chip.npwm = NUM_PWM; + + ret = pwmchip_add(&pwm->chip); + if (ret < 0) { + dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); + return ret; + } + + return 0; +} + +static int mtk_disp_pwm_remove(struct platform_device *pdev) +{ + struct mtk_disp_pwm_chip *pc = platform_get_drvdata(pdev); + + if (WARN_ON(!pc)) + return -ENODEV; + + clk_disable_unprepare(pc->clk_main); + clk_disable_unprepare(pc->clk_mm); + + return pwmchip_remove(&pc->chip); +} + +static const struct of_device_id mtk_disp_pwm_of_match[] = { + { .compatible = "mediatek,mt6595-disp-pwm" }, + { } +}; + +MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match); + +static struct platform_driver mtk_disp_pwm_driver = { + .driver = { + .name = "mediatek-disp-pwm", + .owner = THIS_MODULE, + .of_match_table = mtk_disp_pwm_of_match, + }, + .probe = mtk_disp_pwm_probe, + .remove = mtk_disp_pwm_remove, +}; + +module_platform_driver(mtk_disp_pwm_driver); + +MODULE_AUTHOR("YH Huang "); +MODULE_DESCRIPTION("MediaTek SoC display PWM driver"); +MODULE_LICENSE("GPL v2");