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16#include <linux/bitfield.h>
17#include <linux/clk.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/mod_devicetable.h>
21#include <linux/pwm.h>
22#include <linux/regmap.h>
23#include <linux/reset.h>
24
25#define LGM_PWM_FAN_CON0 0x0
26#define LGM_PWM_FAN_EN_EN BIT(0)
27#define LGM_PWM_FAN_EN_DIS 0x0
28#define LGM_PWM_FAN_EN_MSK BIT(0)
29#define LGM_PWM_FAN_MODE_2WIRE 0x0
30#define LGM_PWM_FAN_MODE_MSK BIT(1)
31#define LGM_PWM_FAN_DC_MSK GENMASK(23, 16)
32
33#define LGM_PWM_FAN_CON1 0x4
34#define LGM_PWM_FAN_MAX_RPM_MSK GENMASK(15, 0)
35
36#define LGM_PWM_MAX_RPM (BIT(16) - 1)
37#define LGM_PWM_DEFAULT_RPM 4000
38#define LGM_PWM_MAX_DUTY_CYCLE (BIT(8) - 1)
39
40#define LGM_PWM_DC_BITS 8
41
42#define LGM_PWM_PERIOD_2WIRE_NS (40 * NSEC_PER_MSEC)
43
44struct lgm_pwm_chip {
45 struct pwm_chip chip;
46 struct regmap *regmap;
47 u32 period;
48};
49
50static inline struct lgm_pwm_chip *to_lgm_pwm_chip(struct pwm_chip *chip)
51{
52 return container_of(chip, struct lgm_pwm_chip, chip);
53}
54
55static int lgm_pwm_enable(struct pwm_chip *chip, bool enable)
56{
57 struct lgm_pwm_chip *pc = to_lgm_pwm_chip(chip);
58 struct regmap *regmap = pc->regmap;
59
60 return regmap_update_bits(regmap, LGM_PWM_FAN_CON0, LGM_PWM_FAN_EN_MSK,
61 enable ? LGM_PWM_FAN_EN_EN : LGM_PWM_FAN_EN_DIS);
62}
63
64static int lgm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
65 const struct pwm_state *state)
66{
67 struct lgm_pwm_chip *pc = to_lgm_pwm_chip(chip);
68 u32 duty_cycle, val;
69 int ret;
70
71
72 if (state->polarity != PWM_POLARITY_NORMAL || state->period < pc->period)
73 return -EINVAL;
74
75 if (!state->enabled)
76 return lgm_pwm_enable(chip, 0);
77
78 duty_cycle = min_t(u64, state->duty_cycle, pc->period);
79 val = duty_cycle * LGM_PWM_MAX_DUTY_CYCLE / pc->period;
80
81 ret = regmap_update_bits(pc->regmap, LGM_PWM_FAN_CON0, LGM_PWM_FAN_DC_MSK,
82 FIELD_PREP(LGM_PWM_FAN_DC_MSK, val));
83 if (ret)
84 return ret;
85
86 return lgm_pwm_enable(chip, 1);
87}
88
89static void lgm_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
90 struct pwm_state *state)
91{
92 struct lgm_pwm_chip *pc = to_lgm_pwm_chip(chip);
93 u32 duty, val;
94
95 state->enabled = regmap_test_bits(pc->regmap, LGM_PWM_FAN_CON0,
96 LGM_PWM_FAN_EN_EN);
97 state->polarity = PWM_POLARITY_NORMAL;
98 state->period = pc->period;
99
100 regmap_read(pc->regmap, LGM_PWM_FAN_CON0, &val);
101 duty = FIELD_GET(LGM_PWM_FAN_DC_MSK, val);
102 state->duty_cycle = DIV_ROUND_UP(duty * pc->period, LGM_PWM_MAX_DUTY_CYCLE);
103}
104
105static const struct pwm_ops lgm_pwm_ops = {
106 .get_state = lgm_pwm_get_state,
107 .apply = lgm_pwm_apply,
108 .owner = THIS_MODULE,
109};
110
111static void lgm_pwm_init(struct lgm_pwm_chip *pc)
112{
113 struct regmap *regmap = pc->regmap;
114 u32 con0_val;
115
116 con0_val = FIELD_PREP(LGM_PWM_FAN_MODE_MSK, LGM_PWM_FAN_MODE_2WIRE);
117 pc->period = LGM_PWM_PERIOD_2WIRE_NS;
118 regmap_update_bits(regmap, LGM_PWM_FAN_CON1, LGM_PWM_FAN_MAX_RPM_MSK,
119 LGM_PWM_DEFAULT_RPM);
120 regmap_update_bits(regmap, LGM_PWM_FAN_CON0, LGM_PWM_FAN_MODE_MSK,
121 con0_val);
122}
123
124static const struct regmap_config lgm_pwm_regmap_config = {
125 .reg_bits = 32,
126 .reg_stride = 4,
127 .val_bits = 32,
128};
129
130static void lgm_clk_release(void *data)
131{
132 struct clk *clk = data;
133
134 clk_disable_unprepare(clk);
135}
136
137static int lgm_clk_enable(struct device *dev, struct clk *clk)
138{
139 int ret;
140
141 ret = clk_prepare_enable(clk);
142 if (ret)
143 return ret;
144
145 return devm_add_action_or_reset(dev, lgm_clk_release, clk);
146}
147
148static void lgm_reset_control_release(void *data)
149{
150 struct reset_control *rst = data;
151
152 reset_control_assert(rst);
153}
154
155static int lgm_reset_control_deassert(struct device *dev, struct reset_control *rst)
156{
157 int ret;
158
159 ret = reset_control_deassert(rst);
160 if (ret)
161 return ret;
162
163 return devm_add_action_or_reset(dev, lgm_reset_control_release, rst);
164}
165
166static int lgm_pwm_probe(struct platform_device *pdev)
167{
168 struct device *dev = &pdev->dev;
169 struct reset_control *rst;
170 struct lgm_pwm_chip *pc;
171 void __iomem *io_base;
172 struct clk *clk;
173 int ret;
174
175 pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
176 if (!pc)
177 return -ENOMEM;
178
179 io_base = devm_platform_ioremap_resource(pdev, 0);
180 if (IS_ERR(io_base))
181 return PTR_ERR(io_base);
182
183 pc->regmap = devm_regmap_init_mmio(dev, io_base, &lgm_pwm_regmap_config);
184 if (IS_ERR(pc->regmap))
185 return dev_err_probe(dev, PTR_ERR(pc->regmap),
186 "failed to init register map\n");
187
188 clk = devm_clk_get(dev, NULL);
189 if (IS_ERR(clk))
190 return dev_err_probe(dev, PTR_ERR(clk), "failed to get clock\n");
191
192 ret = lgm_clk_enable(dev, clk);
193 if (ret)
194 return dev_err_probe(dev, ret, "failed to enable clock\n");
195
196 rst = devm_reset_control_get_exclusive(dev, NULL);
197 if (IS_ERR(rst))
198 return dev_err_probe(dev, PTR_ERR(rst),
199 "failed to get reset control\n");
200
201 ret = lgm_reset_control_deassert(dev, rst);
202 if (ret)
203 return dev_err_probe(dev, ret, "cannot deassert reset control\n");
204
205 pc->chip.dev = dev;
206 pc->chip.ops = &lgm_pwm_ops;
207 pc->chip.npwm = 1;
208
209 lgm_pwm_init(pc);
210
211 ret = devm_pwmchip_add(dev, &pc->chip);
212 if (ret < 0)
213 return dev_err_probe(dev, ret, "failed to add PWM chip\n");
214
215 return 0;
216}
217
218static const struct of_device_id lgm_pwm_of_match[] = {
219 { .compatible = "intel,lgm-pwm" },
220 { }
221};
222MODULE_DEVICE_TABLE(of, lgm_pwm_of_match);
223
224static struct platform_driver lgm_pwm_driver = {
225 .driver = {
226 .name = "intel-pwm",
227 .of_match_table = lgm_pwm_of_match,
228 },
229 .probe = lgm_pwm_probe,
230};
231module_platform_driver(lgm_pwm_driver);
232
233MODULE_LICENSE("GPL v2");
234
