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path: root/drivers/pwm/pwm-mtk-disp.c
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Diffstat (limited to 'drivers/pwm/pwm-mtk-disp.c')
-rw-r--r--drivers/pwm/pwm-mtk-disp.c332
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
new file mode 100644
index 000000000..db286284f
--- /dev/null
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -0,0 +1,332 @@
+// 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/of_device.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 0;
+ }
+
+ 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 0;
+ }
+
+ /*
+ * 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 int mtk_disp_pwm_remove(struct platform_device *pdev)
+{
+ struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev);
+
+ pwmchip_remove(&mdp->chip);
+
+ return 0;
+}
+
+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 = 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");