1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MediaTek display pulse-width-modulation controller driver.
4 * Copyright (c) 2015 MediaTek Inc.
5 * Author: YH Huang <yh.huang@mediatek.com>
6 */
7
8 #include <linux/bitfield.h>
9 #include <linux/clk.h>
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15 #include <linux/platform_device.h>
16 #include <linux/pwm.h>
17 #include <linux/slab.h>
18
19 #define DISP_PWM_EN 0x00
20
21 #define PWM_CLKDIV_SHIFT 16
22 #define PWM_CLKDIV_MAX 0x3ff
23 #define PWM_CLKDIV_MASK (PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT)
24
25 #define PWM_PERIOD_BIT_WIDTH 12
26 #define PWM_PERIOD_MASK ((1 << PWM_PERIOD_BIT_WIDTH) - 1)
27
28 #define PWM_HIGH_WIDTH_SHIFT 16
29 #define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT)
30
31 struct mtk_pwm_data {
32 u32 enable_mask;
33 unsigned int con0;
34 u32 con0_sel;
35 unsigned int con1;
36
37 bool has_commit;
38 unsigned int commit;
39 unsigned int commit_mask;
40
41 unsigned int bls_debug;
42 u32 bls_debug_mask;
43 };
44
45 struct mtk_disp_pwm {
46 struct pwm_chip chip;
47 const struct mtk_pwm_data *data;
48 struct clk *clk_main;
49 struct clk *clk_mm;
50 void __iomem *base;
51 bool enabled;
52 };
53
to_mtk_disp_pwm(struct pwm_chip * chip)54 static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
55 {
56 return container_of(chip, struct mtk_disp_pwm, chip);
57 }
58
mtk_disp_pwm_update_bits(struct mtk_disp_pwm * mdp,u32 offset,u32 mask,u32 data)59 static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
60 u32 mask, u32 data)
61 {
62 void __iomem *address = mdp->base + offset;
63 u32 value;
64
65 value = readl(address);
66 value &= ~mask;
67 value |= data;
68 writel(value, address);
69 }
70
mtk_disp_pwm_apply(struct pwm_chip * chip,struct pwm_device * pwm,const struct pwm_state * state)71 static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
72 const struct pwm_state *state)
73 {
74 struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
75 u32 clk_div, period, high_width, value;
76 u64 div, rate;
77 int err;
78
79 if (state->polarity != PWM_POLARITY_NORMAL)
80 return -EINVAL;
81
82 if (!state->enabled) {
83 mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
84 0x0);
85
86 if (mdp->enabled) {
87 clk_disable_unprepare(mdp->clk_mm);
88 clk_disable_unprepare(mdp->clk_main);
89 }
90
91 mdp->enabled = false;
92 return 0;
93 }
94
95 if (!mdp->enabled) {
96 err = clk_prepare_enable(mdp->clk_main);
97 if (err < 0) {
98 dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n",
99 ERR_PTR(err));
100 return err;
101 }
102
103 err = clk_prepare_enable(mdp->clk_mm);
104 if (err < 0) {
105 dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n",
106 ERR_PTR(err));
107 clk_disable_unprepare(mdp->clk_main);
108 return err;
109 }
110 }
111
112 /*
113 * Find period, high_width and clk_div to suit duty_ns and period_ns.
114 * Calculate proper div value to keep period value in the bound.
115 *
116 * period_ns = 10^9 * (clk_div + 1) * (period + 1) / PWM_CLK_RATE
117 * duty_ns = 10^9 * (clk_div + 1) * high_width / PWM_CLK_RATE
118 *
119 * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1
120 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
121 */
122 rate = clk_get_rate(mdp->clk_main);
123 clk_div = mul_u64_u64_div_u64(state->period, rate, NSEC_PER_SEC) >>
124 PWM_PERIOD_BIT_WIDTH;
125 if (clk_div > PWM_CLKDIV_MAX) {
126 if (!mdp->enabled) {
127 clk_disable_unprepare(mdp->clk_mm);
128 clk_disable_unprepare(mdp->clk_main);
129 }
130 return -EINVAL;
131 }
132
133 div = NSEC_PER_SEC * (clk_div + 1);
134 period = mul_u64_u64_div_u64(state->period, rate, div);
135 if (period > 0)
136 period--;
137
138 high_width = mul_u64_u64_div_u64(state->duty_cycle, rate, div);
139 value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
140
141 mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
142 PWM_CLKDIV_MASK,
143 clk_div << PWM_CLKDIV_SHIFT);
144 mtk_disp_pwm_update_bits(mdp, mdp->data->con1,
145 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK,
146 value);
147
148 if (mdp->data->has_commit) {
149 mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
150 mdp->data->commit_mask,
151 mdp->data->commit_mask);
152 mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
153 mdp->data->commit_mask,
154 0x0);
155 } else {
156 /*
157 * For MT2701, disable double buffer before writing register
158 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
159 */
160 mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
161 mdp->data->bls_debug_mask,
162 mdp->data->bls_debug_mask);
163 mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
164 mdp->data->con0_sel,
165 mdp->data->con0_sel);
166 }
167
168 mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
169 mdp->data->enable_mask);
170 mdp->enabled = true;
171
172 return 0;
173 }
174
mtk_disp_pwm_get_state(struct pwm_chip * chip,struct pwm_device * pwm,struct pwm_state * state)175 static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
176 struct pwm_device *pwm,
177 struct pwm_state *state)
178 {
179 struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
180 u64 rate, period, high_width;
181 u32 clk_div, pwm_en, con0, con1;
182 int err;
183
184 err = clk_prepare_enable(mdp->clk_main);
185 if (err < 0) {
186 dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", ERR_PTR(err));
187 return;
188 }
189
190 err = clk_prepare_enable(mdp->clk_mm);
191 if (err < 0) {
192 dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", ERR_PTR(err));
193 clk_disable_unprepare(mdp->clk_main);
194 return;
195 }
196
197 rate = clk_get_rate(mdp->clk_main);
198 con0 = readl(mdp->base + mdp->data->con0);
199 con1 = readl(mdp->base + mdp->data->con1);
200 pwm_en = readl(mdp->base + DISP_PWM_EN);
201 state->enabled = !!(pwm_en & mdp->data->enable_mask);
202 clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);
203 period = FIELD_GET(PWM_PERIOD_MASK, con1);
204 /*
205 * period has 12 bits, clk_div 11 and NSEC_PER_SEC has 30,
206 * so period * (clk_div + 1) * NSEC_PER_SEC doesn't overflow.
207 */
208 state->period = DIV64_U64_ROUND_UP(period * (clk_div + 1) * NSEC_PER_SEC, rate);
209 high_width = FIELD_GET(PWM_HIGH_WIDTH_MASK, con1);
210 state->duty_cycle = DIV64_U64_ROUND_UP(high_width * (clk_div + 1) * NSEC_PER_SEC,
211 rate);
212 state->polarity = PWM_POLARITY_NORMAL;
213 clk_disable_unprepare(mdp->clk_mm);
214 clk_disable_unprepare(mdp->clk_main);
215 }
216
217 static const struct pwm_ops mtk_disp_pwm_ops = {
218 .apply = mtk_disp_pwm_apply,
219 .get_state = mtk_disp_pwm_get_state,
220 .owner = THIS_MODULE,
221 };
222
mtk_disp_pwm_probe(struct platform_device * pdev)223 static int mtk_disp_pwm_probe(struct platform_device *pdev)
224 {
225 struct mtk_disp_pwm *mdp;
226 int ret;
227
228 mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL);
229 if (!mdp)
230 return -ENOMEM;
231
232 mdp->data = of_device_get_match_data(&pdev->dev);
233
234 mdp->base = devm_platform_ioremap_resource(pdev, 0);
235 if (IS_ERR(mdp->base))
236 return PTR_ERR(mdp->base);
237
238 mdp->clk_main = devm_clk_get(&pdev->dev, "main");
239 if (IS_ERR(mdp->clk_main))
240 return PTR_ERR(mdp->clk_main);
241
242 mdp->clk_mm = devm_clk_get(&pdev->dev, "mm");
243 if (IS_ERR(mdp->clk_mm))
244 return PTR_ERR(mdp->clk_mm);
245
246 mdp->chip.dev = &pdev->dev;
247 mdp->chip.ops = &mtk_disp_pwm_ops;
248 mdp->chip.npwm = 1;
249
250 ret = pwmchip_add(&mdp->chip);
251 if (ret < 0) {
252 dev_err(&pdev->dev, "pwmchip_add() failed: %pe\n", ERR_PTR(ret));
253 return ret;
254 }
255
256 platform_set_drvdata(pdev, mdp);
257
258 return 0;
259 }
260
mtk_disp_pwm_remove(struct platform_device * pdev)261 static int mtk_disp_pwm_remove(struct platform_device *pdev)
262 {
263 struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev);
264
265 pwmchip_remove(&mdp->chip);
266
267 return 0;
268 }
269
270 static const struct mtk_pwm_data mt2701_pwm_data = {
271 .enable_mask = BIT(16),
272 .con0 = 0xa8,
273 .con0_sel = 0x2,
274 .con1 = 0xac,
275 .has_commit = false,
276 .bls_debug = 0xb0,
277 .bls_debug_mask = 0x3,
278 };
279
280 static const struct mtk_pwm_data mt8173_pwm_data = {
281 .enable_mask = BIT(0),
282 .con0 = 0x10,
283 .con0_sel = 0x0,
284 .con1 = 0x14,
285 .has_commit = true,
286 .commit = 0x8,
287 .commit_mask = 0x1,
288 };
289
290 static const struct mtk_pwm_data mt8183_pwm_data = {
291 .enable_mask = BIT(0),
292 .con0 = 0x18,
293 .con0_sel = 0x0,
294 .con1 = 0x1c,
295 .has_commit = false,
296 .bls_debug = 0x80,
297 .bls_debug_mask = 0x3,
298 };
299
300 static const struct of_device_id mtk_disp_pwm_of_match[] = {
301 { .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data},
302 { .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data},
303 { .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data},
304 { .compatible = "mediatek,mt8183-disp-pwm", .data = &mt8183_pwm_data},
305 { }
306 };
307 MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
308
309 static struct platform_driver mtk_disp_pwm_driver = {
310 .driver = {
311 .name = "mediatek-disp-pwm",
312 .of_match_table = mtk_disp_pwm_of_match,
313 },
314 .probe = mtk_disp_pwm_probe,
315 .remove = mtk_disp_pwm_remove,
316 };
317 module_platform_driver(mtk_disp_pwm_driver);
318
319 MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>");
320 MODULE_DESCRIPTION("MediaTek SoC display PWM driver");
321 MODULE_LICENSE("GPL v2");
322