301 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			301 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  * MediaTek display pulse-width-modulation controller driver.
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|  * Copyright (c) 2015 MediaTek Inc.
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|  * Author: YH Huang <yh.huang@mediatek.com>
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|  */
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| 
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| #include <linux/clk.h>
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| #include <linux/err.h>
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| #include <linux/io.h>
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| #include <linux/module.h>
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| #include <linux/of.h>
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| #include <linux/of_device.h>
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| #include <linux/platform_device.h>
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| #include <linux/pwm.h>
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| #include <linux/slab.h>
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| 
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| #define DISP_PWM_EN		0x00
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| 
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| #define PWM_CLKDIV_SHIFT	16
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| #define PWM_CLKDIV_MAX		0x3ff
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| #define PWM_CLKDIV_MASK		(PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT)
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| 
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| #define PWM_PERIOD_BIT_WIDTH	12
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| #define PWM_PERIOD_MASK		((1 << PWM_PERIOD_BIT_WIDTH) - 1)
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| 
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| #define PWM_HIGH_WIDTH_SHIFT	16
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| #define PWM_HIGH_WIDTH_MASK	(0x1fff << PWM_HIGH_WIDTH_SHIFT)
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| 
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| struct mtk_pwm_data {
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| 	u32 enable_mask;
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| 	unsigned int con0;
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| 	u32 con0_sel;
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| 	unsigned int con1;
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| 
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| 	bool has_commit;
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| 	unsigned int commit;
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| 	unsigned int commit_mask;
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| 
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| 	unsigned int bls_debug;
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| 	u32 bls_debug_mask;
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| };
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| 
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| struct mtk_disp_pwm {
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| 	struct pwm_chip chip;
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| 	const struct mtk_pwm_data *data;
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| 	struct clk *clk_main;
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| 	struct clk *clk_mm;
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| 	void __iomem *base;
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| };
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| 
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| static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
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| {
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| 	return container_of(chip, struct mtk_disp_pwm, chip);
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| }
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| 
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| static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
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| 				     u32 mask, u32 data)
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| {
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| 	void __iomem *address = mdp->base + offset;
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| 	u32 value;
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| 
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| 	value = readl(address);
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| 	value &= ~mask;
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| 	value |= data;
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| 	writel(value, address);
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| }
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| 
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| static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
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| 			       int duty_ns, int period_ns)
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| {
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| 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
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| 	u32 clk_div, period, high_width, value;
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| 	u64 div, rate;
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| 	int err;
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| 
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| 	/*
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| 	 * Find period, high_width and clk_div to suit duty_ns and period_ns.
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| 	 * Calculate proper div value to keep period value in the bound.
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| 	 *
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| 	 * period_ns = 10^9 * (clk_div + 1) * (period + 1) / PWM_CLK_RATE
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| 	 * duty_ns = 10^9 * (clk_div + 1) * high_width / PWM_CLK_RATE
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| 	 *
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| 	 * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1
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| 	 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
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| 	 */
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| 	rate = clk_get_rate(mdp->clk_main);
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| 	clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
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| 			  PWM_PERIOD_BIT_WIDTH;
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| 	if (clk_div > PWM_CLKDIV_MAX)
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| 		return -EINVAL;
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| 
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| 	div = NSEC_PER_SEC * (clk_div + 1);
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| 	period = div64_u64(rate * period_ns, div);
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| 	if (period > 0)
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| 		period--;
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| 
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| 	high_width = div64_u64(rate * duty_ns, div);
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| 	value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
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| 
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| 	err = clk_enable(mdp->clk_main);
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| 	if (err < 0)
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| 		return err;
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| 
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| 	err = clk_enable(mdp->clk_mm);
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| 	if (err < 0) {
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| 		clk_disable(mdp->clk_main);
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| 		return err;
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| 	}
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| 
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| 	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
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| 				 PWM_CLKDIV_MASK,
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| 				 clk_div << PWM_CLKDIV_SHIFT);
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| 	mtk_disp_pwm_update_bits(mdp, mdp->data->con1,
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| 				 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK,
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| 				 value);
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| 
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| 	if (mdp->data->has_commit) {
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| 		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
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| 					 mdp->data->commit_mask,
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| 					 mdp->data->commit_mask);
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| 		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
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| 					 mdp->data->commit_mask,
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| 					 0x0);
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| 	}
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| 
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| 	clk_disable(mdp->clk_mm);
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| 	clk_disable(mdp->clk_main);
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| 
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| 	return 0;
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| }
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| 
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| static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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| {
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| 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
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| 	int err;
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| 
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| 	err = clk_enable(mdp->clk_main);
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| 	if (err < 0)
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| 		return err;
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| 
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| 	err = clk_enable(mdp->clk_mm);
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| 	if (err < 0) {
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| 		clk_disable(mdp->clk_main);
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| 		return err;
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| 	}
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| 
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| 	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
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| 				 mdp->data->enable_mask);
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| 
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| 	return 0;
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| }
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| 
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| static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
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| {
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| 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
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| 
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| 	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
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| 				 0x0);
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| 
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| 	clk_disable(mdp->clk_mm);
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| 	clk_disable(mdp->clk_main);
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| }
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| 
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| static const struct pwm_ops mtk_disp_pwm_ops = {
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| 	.config = mtk_disp_pwm_config,
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| 	.enable = mtk_disp_pwm_enable,
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| 	.disable = mtk_disp_pwm_disable,
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| 	.owner = THIS_MODULE,
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| };
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| 
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| static int mtk_disp_pwm_probe(struct platform_device *pdev)
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| {
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| 	struct mtk_disp_pwm *mdp;
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| 	int ret;
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| 
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| 	mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL);
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| 	if (!mdp)
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| 		return -ENOMEM;
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| 
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| 	mdp->data = of_device_get_match_data(&pdev->dev);
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| 
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| 	mdp->base = devm_platform_ioremap_resource(pdev, 0);
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| 	if (IS_ERR(mdp->base))
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| 		return PTR_ERR(mdp->base);
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| 
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| 	mdp->clk_main = devm_clk_get(&pdev->dev, "main");
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| 	if (IS_ERR(mdp->clk_main))
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| 		return PTR_ERR(mdp->clk_main);
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| 
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| 	mdp->clk_mm = devm_clk_get(&pdev->dev, "mm");
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| 	if (IS_ERR(mdp->clk_mm))
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| 		return PTR_ERR(mdp->clk_mm);
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| 
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| 	ret = clk_prepare(mdp->clk_main);
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| 	if (ret < 0)
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| 		return ret;
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| 
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| 	ret = clk_prepare(mdp->clk_mm);
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| 	if (ret < 0)
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| 		goto disable_clk_main;
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| 
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| 	mdp->chip.dev = &pdev->dev;
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| 	mdp->chip.ops = &mtk_disp_pwm_ops;
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| 	mdp->chip.npwm = 1;
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| 
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| 	ret = pwmchip_add(&mdp->chip);
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| 	if (ret < 0) {
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| 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
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| 		goto disable_clk_mm;
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| 	}
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| 
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| 	platform_set_drvdata(pdev, mdp);
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| 
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| 	/*
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| 	 * For MT2701, disable double buffer before writing register
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| 	 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
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| 	 */
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| 	if (!mdp->data->has_commit) {
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| 		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
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| 					 mdp->data->bls_debug_mask,
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| 					 mdp->data->bls_debug_mask);
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| 		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
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| 					 mdp->data->con0_sel,
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| 					 mdp->data->con0_sel);
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| 	}
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| 
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| 	return 0;
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| 
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| disable_clk_mm:
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| 	clk_unprepare(mdp->clk_mm);
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| disable_clk_main:
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| 	clk_unprepare(mdp->clk_main);
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| 	return ret;
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| }
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| 
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| static int mtk_disp_pwm_remove(struct platform_device *pdev)
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| {
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| 	struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev);
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| 	int ret;
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| 
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| 	ret = pwmchip_remove(&mdp->chip);
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| 	clk_unprepare(mdp->clk_mm);
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| 	clk_unprepare(mdp->clk_main);
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| 
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| 	return ret;
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| }
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| 
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| static const struct mtk_pwm_data mt2701_pwm_data = {
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| 	.enable_mask = BIT(16),
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| 	.con0 = 0xa8,
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| 	.con0_sel = 0x2,
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| 	.con1 = 0xac,
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| 	.has_commit = false,
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| 	.bls_debug = 0xb0,
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| 	.bls_debug_mask = 0x3,
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| };
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| 
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| static const struct mtk_pwm_data mt8173_pwm_data = {
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| 	.enable_mask = BIT(0),
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| 	.con0 = 0x10,
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| 	.con0_sel = 0x0,
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| 	.con1 = 0x14,
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| 	.has_commit = true,
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| 	.commit = 0x8,
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| 	.commit_mask = 0x1,
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| };
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| 
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| static const struct mtk_pwm_data mt8183_pwm_data = {
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| 	.enable_mask = BIT(0),
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| 	.con0 = 0x18,
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| 	.con0_sel = 0x0,
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| 	.con1 = 0x1c,
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| 	.has_commit = false,
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| 	.bls_debug = 0x80,
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| 	.bls_debug_mask = 0x3,
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| };
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| 
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| static const struct of_device_id mtk_disp_pwm_of_match[] = {
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| 	{ .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data},
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| 	{ .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data},
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| 	{ .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data},
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| 	{ .compatible = "mediatek,mt8183-disp-pwm", .data = &mt8183_pwm_data},
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| 	{ }
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| };
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| MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
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| 
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| static struct platform_driver mtk_disp_pwm_driver = {
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| 	.driver = {
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| 		.name = "mediatek-disp-pwm",
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| 		.of_match_table = mtk_disp_pwm_of_match,
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| 	},
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| 	.probe = mtk_disp_pwm_probe,
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| 	.remove = mtk_disp_pwm_remove,
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| };
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| module_platform_driver(mtk_disp_pwm_driver);
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| 
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| MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>");
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| MODULE_DESCRIPTION("MediaTek SoC display PWM driver");
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| MODULE_LICENSE("GPL v2");
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