1 // SPDX-License-Identifier: GPL-2.0
3  * simple driver for PWM (Pulse Width Modulator) controller
5  * Derived from pxa PWM driver by eric miao <eric.miao@marvell.com>
18 #include <linux/pwm.h>
21 #define MX1_PWMC			0x00   /* PWM Control Register */
22 #define MX1_PWMS			0x04   /* PWM Sample Register */
23 #define MX1_PWMP			0x08   /* PWM Period Register */
43 	ret = clk_prepare_enable(imx->clk_ipg);  in pwm_imx1_clk_prepare_enable()
47 	ret = clk_prepare_enable(imx->clk_per);  in pwm_imx1_clk_prepare_enable()
49 		clk_disable_unprepare(imx->clk_ipg);  in pwm_imx1_clk_prepare_enable()
60 	clk_disable_unprepare(imx->clk_per);  in pwm_imx1_clk_disable_unprepare()
61 	clk_disable_unprepare(imx->clk_ipg);  in pwm_imx1_clk_disable_unprepare()
65 			   struct pwm_device *pwm, u64 duty_ns, u64 period_ns)  in pwm_imx1_config()  argument
71 	 * The PWM subsystem allows for exact frequencies. However,  in pwm_imx1_config()
72 	 * I cannot connect a scope on my device to the PWM line and  in pwm_imx1_config()
73 	 * thus cannot provide the program the PWM controller  in pwm_imx1_config()
75 	 * Bootloader (u-boot or WinCE+haret) has programmed the PWM  in pwm_imx1_config()
76 	 * function group already. So I'll just modify the PWM sample  in pwm_imx1_config()
87 	max = readl(imx->mmio_base + MX1_PWMP);  in pwm_imx1_config()
90 	writel(max - p, imx->mmio_base + MX1_PWMS);  in pwm_imx1_config()
95 static int pwm_imx1_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_imx1_enable()  argument
105 	value = readl(imx->mmio_base + MX1_PWMC);  in pwm_imx1_enable()
107 	writel(value, imx->mmio_base + MX1_PWMC);  in pwm_imx1_enable()
112 static void pwm_imx1_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_imx1_disable()  argument
117 	value = readl(imx->mmio_base + MX1_PWMC);  in pwm_imx1_disable()
119 	writel(value, imx->mmio_base + MX1_PWMC);  in pwm_imx1_disable()
124 static int pwm_imx1_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in pwm_imx1_apply()  argument
129 	if (state->polarity != PWM_POLARITY_NORMAL)  in pwm_imx1_apply()
130 		return -EINVAL;  in pwm_imx1_apply()
132 	if (!state->enabled) {  in pwm_imx1_apply()
133 		if (pwm->state.enabled)  in pwm_imx1_apply()
134 			pwm_imx1_disable(chip, pwm);  in pwm_imx1_apply()
139 	err = pwm_imx1_config(chip, pwm, state->duty_cycle, state->period);  in pwm_imx1_apply()
143 	if (!pwm->state.enabled)  in pwm_imx1_apply()
144 		return pwm_imx1_enable(chip, pwm);  in pwm_imx1_apply()
154 	{ .compatible = "fsl,imx1-pwm", },
164 	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*imx));  in pwm_imx1_probe()
169 	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");  in pwm_imx1_probe()
170 	if (IS_ERR(imx->clk_ipg))  in pwm_imx1_probe()
171 		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_ipg),  in pwm_imx1_probe()
174 	imx->clk_per = devm_clk_get(&pdev->dev, "per");  in pwm_imx1_probe()
175 	if (IS_ERR(imx->clk_per))  in pwm_imx1_probe()
176 		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_per),  in pwm_imx1_probe()
179 	chip->ops = &pwm_imx1_ops;  in pwm_imx1_probe()
181 	imx->mmio_base = devm_platform_ioremap_resource(pdev, 0);  in pwm_imx1_probe()
182 	if (IS_ERR(imx->mmio_base))  in pwm_imx1_probe()
183 		return PTR_ERR(imx->mmio_base);  in pwm_imx1_probe()
185 	return devm_pwmchip_add(&pdev->dev, chip);  in pwm_imx1_probe()
190 		.name = "pwm-imx1",