1 // SPDX-License-Identifier: GPL-2.0-only
3 * Analog Devices ADP5585 PWM driver
6 * Copyright 2024 Ideas on Board Oy
9 * - The .apply() operation executes atomically, but may not wait for the
10 * period to complete (this is not documented and would need to be tested).
11 * - Disabling the PWM drives the output pin to a low level immediately.
12 * - The hardware can only generate normal polarity output.
15 #include <asm/byteorder.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/math64.h>
20 #include <linux/mfd/adp5585.h>
21 #include <linux/minmax.h>
22 #include <linux/module.h>
23 #include <linux/platform_device.h>
24 #include <linux/pwm.h>
25 #include <linux/regmap.h>
26 #include <linux/time.h>
27 #include <linux/types.h>
29 #define ADP5585_PWM_CHAN_NUM 1
31 #define ADP5585_PWM_OSC_FREQ_HZ 1000000U
32 #define ADP5585_PWM_MIN_PERIOD_NS (2ULL * NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ)
33 #define ADP5585_PWM_MAX_PERIOD_NS (2ULL * 0xffff * NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ)
35 static int pwm_adp5585_request(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
37 struct regmap
*regmap
= pwmchip_get_drvdata(chip
);
39 /* Configure the R3 pin as PWM output. */
40 return regmap_update_bits(regmap
, ADP5585_PIN_CONFIG_C
,
41 ADP5585_R3_EXTEND_CFG_MASK
,
42 ADP5585_R3_EXTEND_CFG_PWM_OUT
);
45 static void pwm_adp5585_free(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
47 struct regmap
*regmap
= pwmchip_get_drvdata(chip
);
49 regmap_update_bits(regmap
, ADP5585_PIN_CONFIG_C
,
50 ADP5585_R3_EXTEND_CFG_MASK
,
51 ADP5585_R3_EXTEND_CFG_GPIO4
);
54 static int pwm_adp5585_apply(struct pwm_chip
*chip
,
55 struct pwm_device
*pwm
,
56 const struct pwm_state
*state
)
58 struct regmap
*regmap
= pwmchip_get_drvdata(chip
);
59 u64 period
, duty_cycle
;
64 if (!state
->enabled
) {
65 regmap_clear_bits(regmap
, ADP5585_GENERAL_CFG
, ADP5585_OSC_EN
);
66 regmap_clear_bits(regmap
, ADP5585_PWM_CFG
, ADP5585_PWM_EN
);
70 if (state
->polarity
!= PWM_POLARITY_NORMAL
)
73 if (state
->period
< ADP5585_PWM_MIN_PERIOD_NS
)
76 period
= min(state
->period
, ADP5585_PWM_MAX_PERIOD_NS
);
77 duty_cycle
= min(state
->duty_cycle
, period
);
80 * Compute the on and off time. As the internal oscillator frequency is
81 * 1MHz, the calculation can be simplified without loss of precision.
83 on
= div_u64(duty_cycle
, NSEC_PER_SEC
/ ADP5585_PWM_OSC_FREQ_HZ
);
84 off
= div_u64(period
, NSEC_PER_SEC
/ ADP5585_PWM_OSC_FREQ_HZ
) - on
;
86 val
= cpu_to_le16(off
);
87 ret
= regmap_bulk_write(regmap
, ADP5585_PWM_OFFT_LOW
, &val
, 2);
91 val
= cpu_to_le16(on
);
92 ret
= regmap_bulk_write(regmap
, ADP5585_PWM_ONT_LOW
, &val
, 2);
96 /* Enable PWM in continuous mode and no external AND'ing. */
97 ret
= regmap_update_bits(regmap
, ADP5585_PWM_CFG
,
98 ADP5585_PWM_IN_AND
| ADP5585_PWM_MODE
|
99 ADP5585_PWM_EN
, ADP5585_PWM_EN
);
103 ret
= regmap_set_bits(regmap
, ADP5585_GENERAL_CFG
, ADP5585_OSC_EN
);
107 return regmap_set_bits(regmap
, ADP5585_PWM_CFG
, ADP5585_PWM_EN
);
110 static int pwm_adp5585_get_state(struct pwm_chip
*chip
,
111 struct pwm_device
*pwm
,
112 struct pwm_state
*state
)
114 struct regmap
*regmap
= pwmchip_get_drvdata(chip
);
115 unsigned int on
, off
;
120 ret
= regmap_bulk_read(regmap
, ADP5585_PWM_OFFT_LOW
, &on_off
, 2);
123 off
= le16_to_cpu(on_off
);
125 ret
= regmap_bulk_read(regmap
, ADP5585_PWM_ONT_LOW
, &on_off
, 2);
128 on
= le16_to_cpu(on_off
);
130 state
->duty_cycle
= on
* (NSEC_PER_SEC
/ ADP5585_PWM_OSC_FREQ_HZ
);
131 state
->period
= (on
+ off
) * (NSEC_PER_SEC
/ ADP5585_PWM_OSC_FREQ_HZ
);
133 state
->polarity
= PWM_POLARITY_NORMAL
;
135 regmap_read(regmap
, ADP5585_PWM_CFG
, &val
);
136 state
->enabled
= !!(val
& ADP5585_PWM_EN
);
141 static const struct pwm_ops adp5585_pwm_ops
= {
142 .request
= pwm_adp5585_request
,
143 .free
= pwm_adp5585_free
,
144 .apply
= pwm_adp5585_apply
,
145 .get_state
= pwm_adp5585_get_state
,
148 static int adp5585_pwm_probe(struct platform_device
*pdev
)
150 struct device
*dev
= &pdev
->dev
;
151 struct adp5585_dev
*adp5585
= dev_get_drvdata(dev
->parent
);
152 struct pwm_chip
*chip
;
155 chip
= devm_pwmchip_alloc(dev
, ADP5585_PWM_CHAN_NUM
, 0);
157 return PTR_ERR(chip
);
159 device_set_of_node_from_dev(dev
, dev
->parent
);
161 pwmchip_set_drvdata(chip
, adp5585
->regmap
);
162 chip
->ops
= &adp5585_pwm_ops
;
164 ret
= devm_pwmchip_add(dev
, chip
);
166 return dev_err_probe(dev
, ret
, "failed to add PWM chip\n");
171 static const struct platform_device_id adp5585_pwm_id_table
[] = {
175 MODULE_DEVICE_TABLE(platform
, adp5585_pwm_id_table
);
177 static struct platform_driver adp5585_pwm_driver
= {
179 .name
= "adp5585-pwm",
181 .probe
= adp5585_pwm_probe
,
182 .id_table
= adp5585_pwm_id_table
,
184 module_platform_driver(adp5585_pwm_driver
);
186 MODULE_AUTHOR("Xiaoning Wang <xiaoning.wang@nxp.com>");
187 MODULE_DESCRIPTION("ADP5585 PWM Driver");
188 MODULE_LICENSE("GPL");