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/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 30 struct 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 44 struct 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 bool enabled; 51 }; 52 53 static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip) 54 { 55 return container_of(chip, struct mtk_disp_pwm, chip); 56 } 57 58 static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset, 59 u32 mask, u32 data) 60 { 61 void __iomem *address = mdp->base + offset; 62 u32 value; 63 64 value = readl(address); 65 value &= ~mask; 66 value |= data; 67 writel(value, address); 68 } 69 70 static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, 71 const struct pwm_state *state) 72 { 73 struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); 74 u32 clk_div, period, high_width, value; 75 u64 div, rate; 76 int err; 77 78 if (state->polarity != PWM_POLARITY_NORMAL) 79 return -EINVAL; 80 81 if (!state->enabled && mdp->enabled) { 82 mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, 83 mdp->data->enable_mask, 0x0); 84 clk_disable_unprepare(mdp->clk_mm); 85 clk_disable_unprepare(mdp->clk_main); 86 87 mdp->enabled = false; 88 return 0; 89 } 90 91 if (!mdp->enabled) { 92 err = clk_prepare_enable(mdp->clk_main); 93 if (err < 0) { 94 dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", 95 ERR_PTR(err)); 96 return err; 97 } 98 99 err = clk_prepare_enable(mdp->clk_mm); 100 if (err < 0) { 101 dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", 102 ERR_PTR(err)); 103 clk_disable_unprepare(mdp->clk_main); 104 return err; 105 } 106 } 107 108 /* 109 * Find period, high_width and clk_div to suit duty_ns and period_ns. 110 * Calculate proper div value to keep period value in the bound. 111 * 112 * period_ns = 10^9 * (clk_div + 1) * (period + 1) / PWM_CLK_RATE 113 * duty_ns = 10^9 * (clk_div + 1) * high_width / PWM_CLK_RATE 114 * 115 * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1 116 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1)) 117 */ 118 rate = clk_get_rate(mdp->clk_main); 119 clk_div = mul_u64_u64_div_u64(state->period, rate, NSEC_PER_SEC) >> 120 PWM_PERIOD_BIT_WIDTH; 121 if (clk_div > PWM_CLKDIV_MAX) { 122 if (!mdp->enabled) { 123 clk_disable_unprepare(mdp->clk_mm); 124 clk_disable_unprepare(mdp->clk_main); 125 } 126 return -EINVAL; 127 } 128 129 div = NSEC_PER_SEC * (clk_div + 1); 130 period = mul_u64_u64_div_u64(state->period, rate, div); 131 if (period > 0) 132 period--; 133 134 high_width = mul_u64_u64_div_u64(state->duty_cycle, rate, div); 135 value = period | (high_width << PWM_HIGH_WIDTH_SHIFT); 136 137 if (mdp->data->bls_debug && !mdp->data->has_commit) { 138 /* 139 * For MT2701, disable double buffer before writing register 140 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH. 141 */ 142 mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug, 143 mdp->data->bls_debug_mask, 144 mdp->data->bls_debug_mask); 145 mtk_disp_pwm_update_bits(mdp, mdp->data->con0, 146 mdp->data->con0_sel, 147 mdp->data->con0_sel); 148 } 149 150 mtk_disp_pwm_update_bits(mdp, mdp->data->con0, 151 PWM_CLKDIV_MASK, 152 clk_div << PWM_CLKDIV_SHIFT); 153 mtk_disp_pwm_update_bits(mdp, mdp->data->con1, 154 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK, 155 value); 156 157 if (mdp->data->has_commit) { 158 mtk_disp_pwm_update_bits(mdp, mdp->data->commit, 159 mdp->data->commit_mask, 160 mdp->data->commit_mask); 161 mtk_disp_pwm_update_bits(mdp, mdp->data->commit, 162 mdp->data->commit_mask, 163 0x0); 164 } 165 166 mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, 167 mdp->data->enable_mask); 168 mdp->enabled = true; 169 170 return 0; 171 } 172 173 static int mtk_disp_pwm_get_state(struct pwm_chip *chip, 174 struct pwm_device *pwm, 175 struct pwm_state *state) 176 { 177 struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); 178 u64 rate, period, high_width; 179 u32 clk_div, pwm_en, con0, con1; 180 int err; 181 182 err = clk_prepare_enable(mdp->clk_main); 183 if (err < 0) { 184 dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", ERR_PTR(err)); 185 return err; 186 } 187 188 err = clk_prepare_enable(mdp->clk_mm); 189 if (err < 0) { 190 dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", ERR_PTR(err)); 191 clk_disable_unprepare(mdp->clk_main); 192 return err; 193 } 194 195 /* 196 * Apply DISP_PWM_DEBUG settings to choose whether to enable or disable 197 * registers double buffer and manual commit to working register before 198 * performing any read/write operation 199 */ 200 if (mdp->data->bls_debug) 201 mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug, 202 mdp->data->bls_debug_mask, 203 mdp->data->bls_debug_mask); 204 205 rate = clk_get_rate(mdp->clk_main); 206 con0 = readl(mdp->base + mdp->data->con0); 207 con1 = readl(mdp->base + mdp->data->con1); 208 pwm_en = readl(mdp->base + DISP_PWM_EN); 209 state->enabled = !!(pwm_en & mdp->data->enable_mask); 210 clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0); 211 period = FIELD_GET(PWM_PERIOD_MASK, con1); 212 /* 213 * period has 12 bits, clk_div 11 and NSEC_PER_SEC has 30, 214 * so period * (clk_div + 1) * NSEC_PER_SEC doesn't overflow. 215 */ 216 state->period = DIV64_U64_ROUND_UP(period * (clk_div + 1) * NSEC_PER_SEC, rate); 217 high_width = FIELD_GET(PWM_HIGH_WIDTH_MASK, con1); 218 state->duty_cycle = DIV64_U64_ROUND_UP(high_width * (clk_div + 1) * NSEC_PER_SEC, 219 rate); 220 state->polarity = PWM_POLARITY_NORMAL; 221 clk_disable_unprepare(mdp->clk_mm); 222 clk_disable_unprepare(mdp->clk_main); 223 224 return 0; 225 } 226 227 static const struct pwm_ops mtk_disp_pwm_ops = { 228 .apply = mtk_disp_pwm_apply, 229 .get_state = mtk_disp_pwm_get_state, 230 .owner = THIS_MODULE, 231 }; 232 233 static int mtk_disp_pwm_probe(struct platform_device *pdev) 234 { 235 struct mtk_disp_pwm *mdp; 236 int ret; 237 238 mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL); 239 if (!mdp) 240 return -ENOMEM; 241 242 mdp->data = of_device_get_match_data(&pdev->dev); 243 244 mdp->base = devm_platform_ioremap_resource(pdev, 0); 245 if (IS_ERR(mdp->base)) 246 return PTR_ERR(mdp->base); 247 248 mdp->clk_main = devm_clk_get(&pdev->dev, "main"); 249 if (IS_ERR(mdp->clk_main)) 250 return PTR_ERR(mdp->clk_main); 251 252 mdp->clk_mm = devm_clk_get(&pdev->dev, "mm"); 253 if (IS_ERR(mdp->clk_mm)) 254 return PTR_ERR(mdp->clk_mm); 255 256 mdp->chip.dev = &pdev->dev; 257 mdp->chip.ops = &mtk_disp_pwm_ops; 258 mdp->chip.npwm = 1; 259 260 ret = pwmchip_add(&mdp->chip); 261 if (ret < 0) { 262 dev_err(&pdev->dev, "pwmchip_add() failed: %pe\n", ERR_PTR(ret)); 263 return ret; 264 } 265 266 platform_set_drvdata(pdev, mdp); 267 268 return 0; 269 } 270 271 static void mtk_disp_pwm_remove(struct platform_device *pdev) 272 { 273 struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev); 274 275 pwmchip_remove(&mdp->chip); 276 } 277 278 static const struct mtk_pwm_data mt2701_pwm_data = { 279 .enable_mask = BIT(16), 280 .con0 = 0xa8, 281 .con0_sel = 0x2, 282 .con1 = 0xac, 283 .has_commit = false, 284 .bls_debug = 0xb0, 285 .bls_debug_mask = 0x3, 286 }; 287 288 static const struct mtk_pwm_data mt8173_pwm_data = { 289 .enable_mask = BIT(0), 290 .con0 = 0x10, 291 .con0_sel = 0x0, 292 .con1 = 0x14, 293 .has_commit = true, 294 .commit = 0x8, 295 .commit_mask = 0x1, 296 }; 297 298 static const struct mtk_pwm_data mt8183_pwm_data = { 299 .enable_mask = BIT(0), 300 .con0 = 0x18, 301 .con0_sel = 0x0, 302 .con1 = 0x1c, 303 .has_commit = false, 304 .bls_debug = 0x80, 305 .bls_debug_mask = 0x3, 306 }; 307 308 static const struct of_device_id mtk_disp_pwm_of_match[] = { 309 { .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data}, 310 { .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data}, 311 { .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data}, 312 { .compatible = "mediatek,mt8183-disp-pwm", .data = &mt8183_pwm_data}, 313 { } 314 }; 315 MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match); 316 317 static struct platform_driver mtk_disp_pwm_driver = { 318 .driver = { 319 .name = "mediatek-disp-pwm", 320 .of_match_table = mtk_disp_pwm_of_match, 321 }, 322 .probe = mtk_disp_pwm_probe, 323 .remove_new = mtk_disp_pwm_remove, 324 }; 325 module_platform_driver(mtk_disp_pwm_driver); 326 327 MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>"); 328 MODULE_DESCRIPTION("MediaTek SoC display PWM driver"); 329 MODULE_LICENSE("GPL v2"); 330