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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/clk.h>
9#include <linux/err.h>
10#include <linux/io.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/of_device.h>
14#include <linux/platform_device.h>
15#include <linux/pwm.h>
16#include <linux/slab.h>
17
18#define DISP_PWM_EN 0x00
19
20#define PWM_CLKDIV_SHIFT 16
21#define PWM_CLKDIV_MAX 0x3ff
22#define PWM_CLKDIV_MASK (PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT)
23
24#define PWM_PERIOD_BIT_WIDTH 12
25#define PWM_PERIOD_MASK ((1 << PWM_PERIOD_BIT_WIDTH) - 1)
26
27#define PWM_HIGH_WIDTH_SHIFT 16
28#define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT)
29
30struct mtk_pwm_data {
31 u32 enable_mask;
32 unsigned int con0;
33 u32 con0_sel;
34 unsigned int con1;
35
36 bool has_commit;
37 unsigned int commit;
38 unsigned int commit_mask;
39
40 unsigned int bls_debug;
41 u32 bls_debug_mask;
42};
43
44struct mtk_disp_pwm {
45 struct pwm_chip chip;
46 const struct mtk_pwm_data *data;
47 struct clk *clk_main;
48 struct clk *clk_mm;
49 void __iomem *base;
50};
51
52static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
53{
54 return container_of(chip, struct mtk_disp_pwm, chip);
55}
56
57static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
58 u32 mask, u32 data)
59{
60 void __iomem *address = mdp->base + offset;
61 u32 value;
62
63 value = readl(address);
64 value &= ~mask;
65 value |= data;
66 writel(value, address);
67}
68
69static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
70 int duty_ns, int period_ns)
71{
72 struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
73 u32 clk_div, period, high_width, value;
74 u64 div, rate;
75 int err;
76
77 /*
78 * Find period, high_width and clk_div to suit duty_ns and period_ns.
79 * Calculate proper div value to keep period value in the bound.
80 *
81 * period_ns = 10^9 * (clk_div + 1) * (period + 1) / PWM_CLK_RATE
82 * duty_ns = 10^9 * (clk_div + 1) * high_width / PWM_CLK_RATE
83 *
84 * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1
85 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
86 */
87 rate = clk_get_rate(mdp->clk_main);
88 clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
89 PWM_PERIOD_BIT_WIDTH;
90 if (clk_div > PWM_CLKDIV_MAX)
91 return -EINVAL;
92
93 div = NSEC_PER_SEC * (clk_div + 1);
94 period = div64_u64(rate * period_ns, div);
95 if (period > 0)
96 period--;
97
98 high_width = div64_u64(rate * duty_ns, div);
99 value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
100
101 err = clk_enable(mdp->clk_main);
102 if (err < 0)
103 return err;
104
105 err = clk_enable(mdp->clk_mm);
106 if (err < 0) {
107 clk_disable(mdp->clk_main);
108 return err;
109 }
110
111 mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
112 PWM_CLKDIV_MASK,
113 clk_div << PWM_CLKDIV_SHIFT);
114 mtk_disp_pwm_update_bits(mdp, mdp->data->con1,
115 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK,
116 value);
117
118 if (mdp->data->has_commit) {
119 mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
120 mdp->data->commit_mask,
121 mdp->data->commit_mask);
122 mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
123 mdp->data->commit_mask,
124 0x0);
125 }
126
127 clk_disable(mdp->clk_mm);
128 clk_disable(mdp->clk_main);
129
130 return 0;
131}
132
133static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
134{
135 struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
136 int err;
137
138 err = clk_enable(mdp->clk_main);
139 if (err < 0)
140 return err;
141
142 err = clk_enable(mdp->clk_mm);
143 if (err < 0) {
144 clk_disable(mdp->clk_main);
145 return err;
146 }
147
148 mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
149 mdp->data->enable_mask);
150
151 return 0;
152}
153
154static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
155{
156 struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
157
158 mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
159 0x0);
160
161 clk_disable(mdp->clk_mm);
162 clk_disable(mdp->clk_main);
163}
164
165static const struct pwm_ops mtk_disp_pwm_ops = {
166 .config = mtk_disp_pwm_config,
167 .enable = mtk_disp_pwm_enable,
168 .disable = mtk_disp_pwm_disable,
169 .owner = THIS_MODULE,
170};
171
172static int mtk_disp_pwm_probe(struct platform_device *pdev)
173{
174 struct mtk_disp_pwm *mdp;
175 struct resource *r;
176 int ret;
177
178 mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL);
179 if (!mdp)
180 return -ENOMEM;
181
182 mdp->data = of_device_get_match_data(&pdev->dev);
183
184 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
185 mdp->base = devm_ioremap_resource(&pdev->dev, r);
186 if (IS_ERR(mdp->base))
187 return PTR_ERR(mdp->base);
188
189 mdp->clk_main = devm_clk_get(&pdev->dev, "main");
190 if (IS_ERR(mdp->clk_main))
191 return PTR_ERR(mdp->clk_main);
192
193 mdp->clk_mm = devm_clk_get(&pdev->dev, "mm");
194 if (IS_ERR(mdp->clk_mm))
195 return PTR_ERR(mdp->clk_mm);
196
197 ret = clk_prepare(mdp->clk_main);
198 if (ret < 0)
199 return ret;
200
201 ret = clk_prepare(mdp->clk_mm);
202 if (ret < 0)
203 goto disable_clk_main;
204
205 mdp->chip.dev = &pdev->dev;
206 mdp->chip.ops = &mtk_disp_pwm_ops;
207 mdp->chip.base = -1;
208 mdp->chip.npwm = 1;
209
210 ret = pwmchip_add(&mdp->chip);
211 if (ret < 0) {
212 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
213 goto disable_clk_mm;
214 }
215
216 platform_set_drvdata(pdev, mdp);
217
218 /*
219 * For MT2701, disable double buffer before writing register
220 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
221 */
222 if (!mdp->data->has_commit) {
223 mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
224 mdp->data->bls_debug_mask,
225 mdp->data->bls_debug_mask);
226 mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
227 mdp->data->con0_sel,
228 mdp->data->con0_sel);
229 }
230
231 return 0;
232
233disable_clk_mm:
234 clk_unprepare(mdp->clk_mm);
235disable_clk_main:
236 clk_unprepare(mdp->clk_main);
237 return ret;
238}
239
240static int mtk_disp_pwm_remove(struct platform_device *pdev)
241{
242 struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev);
243 int ret;
244
245 ret = pwmchip_remove(&mdp->chip);
246 clk_unprepare(mdp->clk_mm);
247 clk_unprepare(mdp->clk_main);
248
249 return ret;
250}
251
252static const struct mtk_pwm_data mt2701_pwm_data = {
253 .enable_mask = BIT(16),
254 .con0 = 0xa8,
255 .con0_sel = 0x2,
256 .con1 = 0xac,
257 .has_commit = false,
258 .bls_debug = 0xb0,
259 .bls_debug_mask = 0x3,
260};
261
262static const struct mtk_pwm_data mt8173_pwm_data = {
263 .enable_mask = BIT(0),
264 .con0 = 0x10,
265 .con0_sel = 0x0,
266 .con1 = 0x14,
267 .has_commit = true,
268 .commit = 0x8,
269 .commit_mask = 0x1,
270};
271
272static const struct mtk_pwm_data mt8183_pwm_data = {
273 .enable_mask = BIT(0),
274 .con0 = 0x18,
275 .con0_sel = 0x0,
276 .con1 = 0x1c,
277 .has_commit = false,
278 .bls_debug = 0x80,
279 .bls_debug_mask = 0x3,
280};
281
282static const struct of_device_id mtk_disp_pwm_of_match[] = {
283 { .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data},
284 { .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data},
285 { .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data},
286 { .compatible = "mediatek,mt8183-disp-pwm", .data = &mt8183_pwm_data},
287 { }
288};
289MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
290
291static struct platform_driver mtk_disp_pwm_driver = {
292 .driver = {
293 .name = "mediatek-disp-pwm",
294 .of_match_table = mtk_disp_pwm_of_match,
295 },
296 .probe = mtk_disp_pwm_probe,
297 .remove = mtk_disp_pwm_remove,
298};
299module_platform_driver(mtk_disp_pwm_driver);
300
301MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>");
302MODULE_DESCRIPTION("MediaTek SoC display PWM driver");
303MODULE_LICENSE("GPL v2");