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>
19 #include <linux/pwm.h>
22 #define MX1_PWMC			0x00   /* PWM Control Register */
23 #define MX1_PWMS			0x04   /* PWM Sample Register */
24 #define MX1_PWMP			0x08   /* PWM Period Register */
42 	ret = clk_prepare_enable(imx->clk_ipg);  in pwm_imx1_clk_prepare_enable()
46 	ret = clk_prepare_enable(imx->clk_per);  in pwm_imx1_clk_prepare_enable()
48 		clk_disable_unprepare(imx->clk_ipg);  in pwm_imx1_clk_prepare_enable()
59 	clk_disable_unprepare(imx->clk_per);  in pwm_imx1_clk_disable_unprepare()
60 	clk_disable_unprepare(imx->clk_ipg);  in pwm_imx1_clk_disable_unprepare()
64 			   struct pwm_device *pwm, int duty_ns, int period_ns)  in pwm_imx1_config()  argument
70 	 * The PWM subsystem allows for exact frequencies. However,  in pwm_imx1_config()
71 	 * I cannot connect a scope on my device to the PWM line and  in pwm_imx1_config()
72 	 * thus cannot provide the program the PWM controller  in pwm_imx1_config()
74 	 * Bootloader (u-boot or WinCE+haret) has programmed the PWM  in pwm_imx1_config()
75 	 * function group already. So I'll just modify the PWM sample  in pwm_imx1_config()
86 	max = readl(imx->mmio_base + MX1_PWMP);  in pwm_imx1_config()
89 	writel(max - p, imx->mmio_base + MX1_PWMS);  in pwm_imx1_config()
94 static int pwm_imx1_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_imx1_enable()  argument
104 	value = readl(imx->mmio_base + MX1_PWMC);  in pwm_imx1_enable()
106 	writel(value, imx->mmio_base + MX1_PWMC);  in pwm_imx1_enable()
111 static void pwm_imx1_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_imx1_disable()  argument
116 	value = readl(imx->mmio_base + MX1_PWMC);  in pwm_imx1_disable()
118 	writel(value, imx->mmio_base + MX1_PWMC);  in pwm_imx1_disable()
131 	{ .compatible = "fsl,imx1-pwm", },
140 	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);  in pwm_imx1_probe()
142 		return -ENOMEM;  in pwm_imx1_probe()
144 	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");  in pwm_imx1_probe()
145 	if (IS_ERR(imx->clk_ipg))  in pwm_imx1_probe()
146 		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_ipg),  in pwm_imx1_probe()
149 	imx->clk_per = devm_clk_get(&pdev->dev, "per");  in pwm_imx1_probe()
150 	if (IS_ERR(imx->clk_per))  in pwm_imx1_probe()
151 		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_per),  in pwm_imx1_probe()
154 	imx->chip.ops = &pwm_imx1_ops;  in pwm_imx1_probe()
155 	imx->chip.dev = &pdev->dev;  in pwm_imx1_probe()
156 	imx->chip.npwm = 1;  in pwm_imx1_probe()
158 	imx->mmio_base = devm_platform_ioremap_resource(pdev, 0);  in pwm_imx1_probe()
159 	if (IS_ERR(imx->mmio_base))  in pwm_imx1_probe()
160 		return PTR_ERR(imx->mmio_base);  in pwm_imx1_probe()
162 	return devm_pwmchip_add(&pdev->dev, &imx->chip);  in pwm_imx1_probe()
167 		.name = "pwm-imx1",