12 #include <linux/clk.h>
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
54 	struct clk *clk;  member
65 	return readl_relaxed(chip->mmio_base + (num << 4) + offset);  in spear_pwm_readl()
72 	writel_relaxed(val, chip->mmio_base + (num << 4) + offset);  in spear_pwm_writel()
75 static int spear_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in spear_pwm_config()  argument
93 	clk_rate = clk_get_rate(pc->clk);  in spear_pwm_config()
104 			return -EINVAL;  in spear_pwm_config()
112 				return -EINVAL;  in spear_pwm_config()
119 	 * NOTE: the clock to PWM has to be enabled first before writing to the  in spear_pwm_config()
122 	ret = clk_enable(pc->clk);  in spear_pwm_config()
126 	spear_pwm_writel(pc, pwm->hwpwm, PWMCR,  in spear_pwm_config()
128 	spear_pwm_writel(pc, pwm->hwpwm, PWMDCR, dc);  in spear_pwm_config()
129 	spear_pwm_writel(pc, pwm->hwpwm, PWMPCR, pv);  in spear_pwm_config()
130 	clk_disable(pc->clk);  in spear_pwm_config()
135 static int spear_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in spear_pwm_enable()  argument
141 	rc = clk_enable(pc->clk);  in spear_pwm_enable()
145 	val = spear_pwm_readl(pc, pwm->hwpwm, PWMCR);  in spear_pwm_enable()
147 	spear_pwm_writel(pc, pwm->hwpwm, PWMCR, val);  in spear_pwm_enable()
152 static void spear_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in spear_pwm_disable()  argument
157 	val = spear_pwm_readl(pc, pwm->hwpwm, PWMCR);  in spear_pwm_disable()
159 	spear_pwm_writel(pc, pwm->hwpwm, PWMCR, val);  in spear_pwm_disable()
161 	clk_disable(pc->clk);  in spear_pwm_disable()
164 static int spear_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in spear_pwm_apply()  argument
169 	if (state->polarity != PWM_POLARITY_NORMAL)  in spear_pwm_apply()
170 		return -EINVAL;  in spear_pwm_apply()
172 	if (!state->enabled) {  in spear_pwm_apply()
173 		if (pwm->state.enabled)  in spear_pwm_apply()
174 			spear_pwm_disable(chip, pwm);  in spear_pwm_apply()
178 	err = spear_pwm_config(chip, pwm, state->duty_cycle, state->period);  in spear_pwm_apply()
182 	if (!pwm->state.enabled)  in spear_pwm_apply()
183 		return spear_pwm_enable(chip, pwm);  in spear_pwm_apply()
194 	struct device_node *np = pdev->dev.of_node;  in spear_pwm_probe()
200 	chip = devm_pwmchip_alloc(&pdev->dev, NUM_PWM, sizeof(*pc));  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 	chip->ops = &spear_pwm_ops;  in spear_pwm_probe()
216 	if (of_device_is_compatible(np, "st,spear1340-pwm")) {  in spear_pwm_probe()
217 		ret = clk_enable(pc->clk);  in spear_pwm_probe()
219 			return dev_err_probe(&pdev->dev, ret,  in spear_pwm_probe()
220 					     "Failed to enable clk\n");  in spear_pwm_probe()
223 		 * Following enables PWM chip, channels would still be  in spear_pwm_probe()
226 		val = readl_relaxed(pc->mmio_base + PWMMCR);  in spear_pwm_probe()
228 		writel_relaxed(val, pc->mmio_base + PWMMCR);  in spear_pwm_probe()
230 		clk_disable(pc->clk);  in spear_pwm_probe()
233 	ret = devm_pwmchip_add(&pdev->dev, chip);  in spear_pwm_probe()
235 		return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");  in spear_pwm_probe()
241 	{ .compatible = "st,spear320-pwm" },
242 	{ .compatible = "st,spear1340-pwm" },
250 		.name = "spear-pwm",
262 MODULE_ALIAS("platform:spear-pwm");