21 #include <linux/pwm.h>
27 /* PWM registers and bits definitions */
47  * struct spear_pwm_chip - struct representing pwm chip
49  * @mmio_base: base address of pwm chip
50  * @clk: pointer to clk structure of pwm chip
51  * @chip: linux pwm chip representation
65 				  unsigned long offset)  in spear_pwm_readl()  argument
67 	return readl_relaxed(chip->mmio_base + (num << 4) + offset);  in spear_pwm_readl()
71 				    unsigned int num, unsigned long offset,  in spear_pwm_writel()  argument
74 	writel_relaxed(val, chip->mmio_base + (num << 4) + offset);  in spear_pwm_writel()
77 static int spear_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in spear_pwm_config()  argument
95 	clk_rate = clk_get_rate(pc->clk);  in spear_pwm_config()
106 			return -EINVAL;  in spear_pwm_config()
114 				return -EINVAL;  in spear_pwm_config()
121 	 * NOTE: the clock to PWM has to be enabled first before writing to the  in spear_pwm_config()
124 	ret = clk_enable(pc->clk);  in spear_pwm_config()
128 	spear_pwm_writel(pc, pwm->hwpwm, PWMCR,  in spear_pwm_config()
130 	spear_pwm_writel(pc, pwm->hwpwm, PWMDCR, dc);  in spear_pwm_config()
131 	spear_pwm_writel(pc, pwm->hwpwm, PWMPCR, pv);  in spear_pwm_config()
132 	clk_disable(pc->clk);  in spear_pwm_config()
137 static int spear_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in spear_pwm_enable()  argument
143 	rc = clk_enable(pc->clk);  in spear_pwm_enable()
147 	val = spear_pwm_readl(pc, pwm->hwpwm, PWMCR);  in spear_pwm_enable()
149 	spear_pwm_writel(pc, pwm->hwpwm, PWMCR, val);  in spear_pwm_enable()
154 static void spear_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in spear_pwm_disable()  argument
159 	val = spear_pwm_readl(pc, pwm->hwpwm, PWMCR);  in spear_pwm_disable()
161 	spear_pwm_writel(pc, pwm->hwpwm, PWMCR, val);  in spear_pwm_disable()
163 	clk_disable(pc->clk);  in spear_pwm_disable()
166 static int spear_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in spear_pwm_apply()  argument
171 	if (state->polarity != PWM_POLARITY_NORMAL)  in spear_pwm_apply()
172 		return -EINVAL;  in spear_pwm_apply()
174 	if (!state->enabled) {  in spear_pwm_apply()
175 		if (pwm->state.enabled)  in spear_pwm_apply()
176 			spear_pwm_disable(chip, pwm);  in spear_pwm_apply()
180 	err = spear_pwm_config(chip, pwm, state->duty_cycle, state->period);  in spear_pwm_apply()
184 	if (!pwm->state.enabled)  in spear_pwm_apply()
185 		return spear_pwm_enable(chip, pwm);  in spear_pwm_apply()
196 	struct device_node *np = pdev->dev.of_node;  in spear_pwm_probe()
201 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);  in spear_pwm_probe()
203 		return -ENOMEM;  in spear_pwm_probe()
205 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);  in spear_pwm_probe()
206 	if (IS_ERR(pc->mmio_base))  in spear_pwm_probe()
207 		return PTR_ERR(pc->mmio_base);  in spear_pwm_probe()
209 	pc->clk = devm_clk_get_prepared(&pdev->dev, NULL);  in spear_pwm_probe()
210 	if (IS_ERR(pc->clk))  in spear_pwm_probe()
211 		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),  in spear_pwm_probe()
214 	pc->chip.dev = &pdev->dev;  in spear_pwm_probe()
215 	pc->chip.ops = &spear_pwm_ops;  in spear_pwm_probe()
216 	pc->chip.npwm = NUM_PWM;  in spear_pwm_probe()
218 	if (of_device_is_compatible(np, "st,spear1340-pwm")) {  in spear_pwm_probe()
219 		ret = clk_enable(pc->clk);  in spear_pwm_probe()
221 			return dev_err_probe(&pdev->dev, ret,  in spear_pwm_probe()
225 		 * Following enables PWM chip, channels would still be  in spear_pwm_probe()
228 		val = readl_relaxed(pc->mmio_base + PWMMCR);  in spear_pwm_probe()
230 		writel_relaxed(val, pc->mmio_base + PWMMCR);  in spear_pwm_probe()
232 		clk_disable(pc->clk);  in spear_pwm_probe()
235 	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);  in spear_pwm_probe()
237 		return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");  in spear_pwm_probe()
243 	{ .compatible = "st,spear320-pwm" },
244 	{ .compatible = "st,spear1340-pwm" },
252 		.name = "spear-pwm",
263 MODULE_ALIAS("platform:spear-pwm");