1 // SPDX-License-Identifier: GPL-2.0-only
3  * drivers/pwm/pwm-pxa.c
5  * simple driver for PWM (Pulse Width Modulator) controller
7  * 2008-02-13	initial version
10  * Links to reference manuals for some of the supported PWM chips can be found
14  * - When PWM is stopped, the current PWM period stops abruptly at the next
24 #include <linux/clk.h>
26 #include <linux/pwm.h>
34 	/*   PWM    has_secondary_pwm? */
35 	{ "pxa25x-pwm", 0 },
36 	{ "pxa27x-pwm", HAS_SECONDARY_PWM },
37 	{ "pxa168-pwm", 0 },
38 	{ "pxa910-pwm", 0 },
43 /* PWM registers and bits definitions */
55 	struct clk	*clk;  member
68 static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in pxa_pwm_config()  argument
76 	offset = pwm->hwpwm ? 0x10 : 0;  in pxa_pwm_config()
78 	c = clk_get_rate(pc->clk);  in pxa_pwm_config()
85 	prescale = (period_cycles - 1) / 1024;  in pxa_pwm_config()
86 	pv = period_cycles / (prescale + 1) - 1;  in pxa_pwm_config()
89 		return -EINVAL;  in pxa_pwm_config()
96 	writel(prescale | PWMCR_SD, pc->mmio_base + offset + PWMCR);  in pxa_pwm_config()
97 	writel(dc, pc->mmio_base + offset + PWMDCR);  in pxa_pwm_config()
98 	writel(pv, pc->mmio_base + offset + PWMPCR);  in pxa_pwm_config()
103 static int pxa_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in pxa_pwm_apply()  argument
110 	if (state->polarity != PWM_POLARITY_NORMAL)  in pxa_pwm_apply()
111 		return -EINVAL;  in pxa_pwm_apply()
113 	err = clk_prepare_enable(pc->clk);  in pxa_pwm_apply()
117 	duty_cycle = state->enabled ? state->duty_cycle : 0;  in pxa_pwm_apply()
119 	err = pxa_pwm_config(chip, pwm, duty_cycle, state->period);  in pxa_pwm_apply()
121 		clk_disable_unprepare(pc->clk);  in pxa_pwm_apply()
125 	if (state->enabled && !pwm->state.enabled)  in pxa_pwm_apply()
128 	clk_disable_unprepare(pc->clk);  in pxa_pwm_apply()
130 	if (!state->enabled && pwm->state.enabled)  in pxa_pwm_apply()
131 		clk_disable_unprepare(pc->clk);  in pxa_pwm_apply()
143  * Device tree users must create one device instance for each PWM channel.
145  * code that this is a single channel pxa25x-pwm.  Currently all devices are
149 	{ .compatible = "marvell,pxa250-pwm", .data = &pwm_id_table[0]},
150 	{ .compatible = "marvell,pxa270-pwm", .data = &pwm_id_table[0]},
151 	{ .compatible = "marvell,pxa168-pwm", .data = &pwm_id_table[0]},
152 	{ .compatible = "marvell,pxa910-pwm", .data = &pwm_id_table[0]},
167 		id = of_device_get_match_data(&pdev->dev);  in pwm_probe()
170 		return -EINVAL;  in pwm_probe()
172 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);  in pwm_probe()
174 		return -ENOMEM;  in pwm_probe()
176 	pc->clk = devm_clk_get(&pdev->dev, NULL);  in pwm_probe()
177 	if (IS_ERR(pc->clk))  in pwm_probe()
178 		return PTR_ERR(pc->clk);  in pwm_probe()
180 	pc->chip.dev = &pdev->dev;  in pwm_probe()
181 	pc->chip.ops = &pxa_pwm_ops;  in pwm_probe()
182 	pc->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;  in pwm_probe()
185 		pc->chip.of_xlate = of_pwm_single_xlate;  in pwm_probe()
186 		pc->chip.of_pwm_n_cells = 1;  in pwm_probe()
189 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);  in pwm_probe()
190 	if (IS_ERR(pc->mmio_base))  in pwm_probe()
191 		return PTR_ERR(pc->mmio_base);  in pwm_probe()
193 	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);  in pwm_probe()
195 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);  in pwm_probe()
204 		.name	= "pxa25x-pwm",