| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * MediaTek display pulse-width-modulation controller driver. |
| * Copyright (c) 2015 MediaTek Inc. |
| * Author: YH Huang <yh.huang@mediatek.com> |
| */ |
| |
| #include <linux/bitfield.h> |
| #include <linux/clk.h> |
| #include <linux/err.h> |
| #include <linux/io.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/platform_device.h> |
| #include <linux/pwm.h> |
| #include <linux/slab.h> |
| |
| #define DISP_PWM_EN 0x00 |
| |
| #define PWM_CLKDIV_SHIFT 16 |
| #define PWM_CLKDIV_MAX 0x3ff |
| #define PWM_CLKDIV_MASK (PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT) |
| |
| #define PWM_PERIOD_BIT_WIDTH 12 |
| #define PWM_PERIOD_MASK ((1 << PWM_PERIOD_BIT_WIDTH) - 1) |
| |
| #define PWM_HIGH_WIDTH_SHIFT 16 |
| #define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT) |
| |
| struct mtk_pwm_data { |
| u32 enable_mask; |
| unsigned int con0; |
| u32 con0_sel; |
| unsigned int con1; |
| |
| bool has_commit; |
| unsigned int commit; |
| unsigned int commit_mask; |
| |
| unsigned int bls_debug; |
| u32 bls_debug_mask; |
| }; |
| |
| struct mtk_disp_pwm { |
| struct pwm_chip chip; |
| const struct mtk_pwm_data *data; |
| struct clk *clk_main; |
| struct clk *clk_mm; |
| void __iomem *base; |
| bool enabled; |
| }; |
| |
| static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip) |
| { |
| return container_of(chip, struct mtk_disp_pwm, chip); |
| } |
| |
| static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset, |
| u32 mask, u32 data) |
| { |
| void __iomem *address = mdp->base + offset; |
| u32 value; |
| |
| value = readl(address); |
| value &= ~mask; |
| value |= data; |
| writel(value, address); |
| } |
| |
| static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
| const struct pwm_state *state) |
| { |
| struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); |
| u32 clk_div, period, high_width, value; |
| u64 div, rate; |
| int err; |
| |
| if (state->polarity != PWM_POLARITY_NORMAL) |
| return -EINVAL; |
| |
| if (!state->enabled && mdp->enabled) { |
| mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, |
| mdp->data->enable_mask, 0x0); |
| clk_disable_unprepare(mdp->clk_mm); |
| clk_disable_unprepare(mdp->clk_main); |
| |
| mdp->enabled = false; |
| return 0; |
| } |
| |
| if (!mdp->enabled) { |
| err = clk_prepare_enable(mdp->clk_main); |
| if (err < 0) { |
| dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", |
| ERR_PTR(err)); |
| return err; |
| } |
| |
| err = clk_prepare_enable(mdp->clk_mm); |
| if (err < 0) { |
| dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", |
| ERR_PTR(err)); |
| clk_disable_unprepare(mdp->clk_main); |
| return err; |
| } |
| } |
| |
| /* |
| * 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 / 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)) |
| */ |
| rate = clk_get_rate(mdp->clk_main); |
| clk_div = mul_u64_u64_div_u64(state->period, rate, NSEC_PER_SEC) >> |
| PWM_PERIOD_BIT_WIDTH; |
| if (clk_div > PWM_CLKDIV_MAX) { |
| if (!mdp->enabled) { |
| clk_disable_unprepare(mdp->clk_mm); |
| clk_disable_unprepare(mdp->clk_main); |
| } |
| return -EINVAL; |
| } |
| |
| div = NSEC_PER_SEC * (clk_div + 1); |
| period = mul_u64_u64_div_u64(state->period, rate, div); |
| if (period > 0) |
| period--; |
| |
| high_width = mul_u64_u64_div_u64(state->duty_cycle, rate, div); |
| value = period | (high_width << PWM_HIGH_WIDTH_SHIFT); |
| |
| if (mdp->data->bls_debug && !mdp->data->has_commit) { |
| /* |
| * For MT2701, disable double buffer before writing register |
| * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH. |
| */ |
| mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug, |
| mdp->data->bls_debug_mask, |
| mdp->data->bls_debug_mask); |
| mtk_disp_pwm_update_bits(mdp, mdp->data->con0, |
| mdp->data->con0_sel, |
| mdp->data->con0_sel); |
| } |
| |
| mtk_disp_pwm_update_bits(mdp, mdp->data->con0, |
| PWM_CLKDIV_MASK, |
| clk_div << PWM_CLKDIV_SHIFT); |
| mtk_disp_pwm_update_bits(mdp, mdp->data->con1, |
| PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK, |
| value); |
| |
| if (mdp->data->has_commit) { |
| mtk_disp_pwm_update_bits(mdp, mdp->data->commit, |
| mdp->data->commit_mask, |
| mdp->data->commit_mask); |
| mtk_disp_pwm_update_bits(mdp, mdp->data->commit, |
| mdp->data->commit_mask, |
| 0x0); |
| } |
| |
| mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, |
| mdp->data->enable_mask); |
| mdp->enabled = true; |
| |
| return 0; |
| } |
| |
| static int mtk_disp_pwm_get_state(struct pwm_chip *chip, |
| struct pwm_device *pwm, |
| struct pwm_state *state) |
| { |
| struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); |
| u64 rate, period, high_width; |
| u32 clk_div, pwm_en, con0, con1; |
| int err; |
| |
| err = clk_prepare_enable(mdp->clk_main); |
| if (err < 0) { |
| dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", ERR_PTR(err)); |
| return err; |
| } |
| |
| err = clk_prepare_enable(mdp->clk_mm); |
| if (err < 0) { |
| dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", ERR_PTR(err)); |
| clk_disable_unprepare(mdp->clk_main); |
| return err; |
| } |
| |
| /* |
| * Apply DISP_PWM_DEBUG settings to choose whether to enable or disable |
| * registers double buffer and manual commit to working register before |
| * performing any read/write operation |
| */ |
| if (mdp->data->bls_debug) |
| mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug, |
| mdp->data->bls_debug_mask, |
| mdp->data->bls_debug_mask); |
| |
| rate = clk_get_rate(mdp->clk_main); |
| con0 = readl(mdp->base + mdp->data->con0); |
| con1 = readl(mdp->base + mdp->data->con1); |
| pwm_en = readl(mdp->base + DISP_PWM_EN); |
| state->enabled = !!(pwm_en & mdp->data->enable_mask); |
| clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0); |
| period = FIELD_GET(PWM_PERIOD_MASK, con1); |
| /* |
| * period has 12 bits, clk_div 11 and NSEC_PER_SEC has 30, |
| * so period * (clk_div + 1) * NSEC_PER_SEC doesn't overflow. |
| */ |
| state->period = DIV64_U64_ROUND_UP(period * (clk_div + 1) * NSEC_PER_SEC, rate); |
| high_width = FIELD_GET(PWM_HIGH_WIDTH_MASK, con1); |
| state->duty_cycle = DIV64_U64_ROUND_UP(high_width * (clk_div + 1) * NSEC_PER_SEC, |
| rate); |
| state->polarity = PWM_POLARITY_NORMAL; |
| clk_disable_unprepare(mdp->clk_mm); |
| clk_disable_unprepare(mdp->clk_main); |
| |
| return 0; |
| } |
| |
| static const struct pwm_ops mtk_disp_pwm_ops = { |
| .apply = mtk_disp_pwm_apply, |
| .get_state = mtk_disp_pwm_get_state, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int mtk_disp_pwm_probe(struct platform_device *pdev) |
| { |
| struct mtk_disp_pwm *mdp; |
| int ret; |
| |
| mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL); |
| if (!mdp) |
| return -ENOMEM; |
| |
| mdp->data = of_device_get_match_data(&pdev->dev); |
| |
| mdp->base = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(mdp->base)) |
| return PTR_ERR(mdp->base); |
| |
| mdp->clk_main = devm_clk_get(&pdev->dev, "main"); |
| if (IS_ERR(mdp->clk_main)) |
| return PTR_ERR(mdp->clk_main); |
| |
| mdp->clk_mm = devm_clk_get(&pdev->dev, "mm"); |
| if (IS_ERR(mdp->clk_mm)) |
| return PTR_ERR(mdp->clk_mm); |
| |
| mdp->chip.dev = &pdev->dev; |
| mdp->chip.ops = &mtk_disp_pwm_ops; |
| mdp->chip.npwm = 1; |
| |
| ret = pwmchip_add(&mdp->chip); |
| if (ret < 0) { |
| dev_err(&pdev->dev, "pwmchip_add() failed: %pe\n", ERR_PTR(ret)); |
| return ret; |
| } |
| |
| platform_set_drvdata(pdev, mdp); |
| |
| return 0; |
| } |
| |
| static void mtk_disp_pwm_remove(struct platform_device *pdev) |
| { |
| struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev); |
| |
| pwmchip_remove(&mdp->chip); |
| } |
| |
| static const struct mtk_pwm_data mt2701_pwm_data = { |
| .enable_mask = BIT(16), |
| .con0 = 0xa8, |
| .con0_sel = 0x2, |
| .con1 = 0xac, |
| .has_commit = false, |
| .bls_debug = 0xb0, |
| .bls_debug_mask = 0x3, |
| }; |
| |
| static const struct mtk_pwm_data mt8173_pwm_data = { |
| .enable_mask = BIT(0), |
| .con0 = 0x10, |
| .con0_sel = 0x0, |
| .con1 = 0x14, |
| .has_commit = true, |
| .commit = 0x8, |
| .commit_mask = 0x1, |
| }; |
| |
| static const struct mtk_pwm_data mt8183_pwm_data = { |
| .enable_mask = BIT(0), |
| .con0 = 0x18, |
| .con0_sel = 0x0, |
| .con1 = 0x1c, |
| .has_commit = false, |
| .bls_debug = 0x80, |
| .bls_debug_mask = 0x3, |
| }; |
| |
| static const struct of_device_id mtk_disp_pwm_of_match[] = { |
| { .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data}, |
| { .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data}, |
| { .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data}, |
| { .compatible = "mediatek,mt8183-disp-pwm", .data = &mt8183_pwm_data}, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match); |
| |
| static struct platform_driver mtk_disp_pwm_driver = { |
| .driver = { |
| .name = "mediatek-disp-pwm", |
| .of_match_table = mtk_disp_pwm_of_match, |
| }, |
| .probe = mtk_disp_pwm_probe, |
| .remove_new = mtk_disp_pwm_remove, |
| }; |
| module_platform_driver(mtk_disp_pwm_driver); |
| |
| MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>"); |
| MODULE_DESCRIPTION("MediaTek SoC display PWM driver"); |
| MODULE_LICENSE("GPL v2"); |