1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Qualcomm Ramp Controller driver 4 * Copyright (c) 2022, AngeloGioacchino Del Regno 5 * <angelogioacchino.delregno@collabora.com> 6 */ 7 8 #include <linux/bitfield.h> 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/of.h> 12 #include <linux/of_platform.h> 13 #include <linux/platform_device.h> 14 #include <linux/regmap.h> 15 #include <linux/types.h> 16 17 #define RC_UPDATE_EN BIT(0) 18 #define RC_ROOT_EN BIT(1) 19 20 #define RC_REG_CFG_UPDATE 0x60 21 #define RC_CFG_UPDATE_EN BIT(8) 22 #define RC_CFG_ACK GENMASK(31, 16) 23 24 #define RC_DCVS_CFG_SID 2 25 #define RC_LINK_SID 3 26 #define RC_LMH_SID 6 27 #define RC_DFS_SID 14 28 29 #define RC_UPDATE_TIMEOUT_US 500 30 31 /** 32 * struct qcom_ramp_controller_desc - SoC specific parameters 33 * @cfg_dfs_sid: Dynamic Frequency Scaling SID configuration 34 * @cfg_link_sid: Link SID configuration 35 * @cfg_lmh_sid: Limits Management hardware SID configuration 36 * @cfg_ramp_en: Ramp Controller enable sequence 37 * @cfg_ramp_dis: Ramp Controller disable sequence 38 * @cmd_reg: Command register offset 39 * @num_dfs_sids: Number of DFS SIDs (max 8) 40 * @num_link_sids: Number of Link SIDs (max 3) 41 * @num_lmh_sids: Number of LMh SIDs (max 8) 42 * @num_ramp_en: Number of entries in enable sequence 43 * @num_ramp_dis: Number of entries in disable sequence 44 */ 45 struct qcom_ramp_controller_desc { 46 const struct reg_sequence *cfg_dfs_sid; 47 const struct reg_sequence *cfg_link_sid; 48 const struct reg_sequence *cfg_lmh_sid; 49 const struct reg_sequence *cfg_ramp_en; 50 const struct reg_sequence *cfg_ramp_dis; 51 u8 cmd_reg; 52 u8 num_dfs_sids; 53 u8 num_link_sids; 54 u8 num_lmh_sids; 55 u8 num_ramp_en; 56 u8 num_ramp_dis; 57 }; 58 59 /** 60 * struct qcom_ramp_controller - Main driver structure 61 * @regmap: Regmap handle 62 * @desc: SoC specific parameters 63 */ 64 struct qcom_ramp_controller { 65 struct regmap *regmap; 66 const struct qcom_ramp_controller_desc *desc; 67 }; 68 69 /** 70 * rc_wait_for_update() - Wait for Ramp Controller root update 71 * @qrc: Main driver structure 72 * 73 * Return: Zero for success or negative number for failure 74 */ 75 static int rc_wait_for_update(struct qcom_ramp_controller *qrc) 76 { 77 const struct qcom_ramp_controller_desc *d = qrc->desc; 78 struct regmap *r = qrc->regmap; 79 u32 val; 80 int ret; 81 82 ret = regmap_set_bits(r, d->cmd_reg, RC_ROOT_EN); 83 if (ret) 84 return ret; 85 86 return regmap_read_poll_timeout(r, d->cmd_reg, val, !(val & RC_UPDATE_EN), 87 1, RC_UPDATE_TIMEOUT_US); 88 } 89 90 /** 91 * rc_set_cfg_update() - Ramp Controller configuration update 92 * @qrc: Main driver structure 93 * @ce: Configuration entry to update 94 * 95 * Return: Zero for success or negative number for failure 96 */ 97 static int rc_set_cfg_update(struct qcom_ramp_controller *qrc, u8 ce) 98 { 99 const struct qcom_ramp_controller_desc *d = qrc->desc; 100 struct regmap *r = qrc->regmap; 101 u32 ack, val; 102 int ret; 103 104 /* The ack bit is between bits 16-31 of RC_REG_CFG_UPDATE */ 105 ack = FIELD_PREP(RC_CFG_ACK, BIT(ce)); 106 107 /* Write the configuration type first... */ 108 ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, ce); 109 if (ret) 110 return ret; 111 112 /* ...and after that, enable the update bit to sync the changes */ 113 ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, RC_CFG_UPDATE_EN); 114 if (ret) 115 return ret; 116 117 /* Wait for the changes to go through */ 118 ret = regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE, val, 119 val & ack, 1, RC_UPDATE_TIMEOUT_US); 120 if (ret) 121 return ret; 122 123 /* 124 * Configuration update success! The CFG_UPDATE register will not be 125 * cleared automatically upon applying the configuration, so we have 126 * to do that manually in order to leave the ramp controller in a 127 * predictable and clean state. 128 */ 129 ret = regmap_write(r, d->cmd_reg + RC_REG_CFG_UPDATE, 0); 130 if (ret) 131 return ret; 132 133 /* Wait for the update bit cleared ack */ 134 return regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE, 135 val, !(val & RC_CFG_ACK), 1, 136 RC_UPDATE_TIMEOUT_US); 137 } 138 139 /** 140 * rc_write_cfg - Send configuration sequence 141 * @qrc: Main driver structure 142 * @seq: Register sequence to send before asking for update 143 * @ce: Configuration SID 144 * @nsids: Total number of SIDs 145 * 146 * Returns: Zero for success or negative number for error 147 */ 148 static int rc_write_cfg(struct qcom_ramp_controller *qrc, 149 const struct reg_sequence *seq, 150 u16 ce, u8 nsids) 151 { 152 int ret; 153 u8 i; 154 155 /* Check if, and wait until the ramp controller is ready */ 156 ret = rc_wait_for_update(qrc); 157 if (ret) 158 return ret; 159 160 /* Write the sequence */ 161 ret = regmap_multi_reg_write(qrc->regmap, seq, nsids); 162 if (ret) 163 return ret; 164 165 /* Pull the trigger: do config update starting from the last sid */ 166 for (i = 0; i < nsids; i++) { 167 ret = rc_set_cfg_update(qrc, (u8)ce - i); 168 if (ret) 169 return ret; 170 } 171 172 return 0; 173 } 174 175 /** 176 * rc_ramp_ctrl_enable() - Enable Ramp up/down Control 177 * @qrc: Main driver structure 178 * 179 * Return: Zero for success or negative number for error 180 */ 181 static int rc_ramp_ctrl_enable(struct qcom_ramp_controller *qrc) 182 { 183 const struct qcom_ramp_controller_desc *d = qrc->desc; 184 int i, ret; 185 186 for (i = 0; i < d->num_ramp_en; i++) { 187 ret = rc_write_cfg(qrc, &d->cfg_ramp_en[i], RC_DCVS_CFG_SID, 1); 188 if (ret) 189 return ret; 190 } 191 192 return 0; 193 } 194 195 /** 196 * qcom_ramp_controller_start() - Initialize and start the ramp controller 197 * @qrc: Main driver structure 198 * 199 * The Ramp Controller needs to be initialized by programming the relevant 200 * registers with SoC-specific configuration: once programming is done, 201 * the hardware will take care of the rest (no further handling required). 202 * 203 * Return: Zero for success or negative number for error 204 */ 205 static int qcom_ramp_controller_start(struct qcom_ramp_controller *qrc) 206 { 207 const struct qcom_ramp_controller_desc *d = qrc->desc; 208 int ret; 209 210 /* Program LMH, DFS, Link SIDs */ 211 ret = rc_write_cfg(qrc, d->cfg_lmh_sid, RC_LMH_SID, d->num_lmh_sids); 212 if (ret) 213 return ret; 214 215 ret = rc_write_cfg(qrc, d->cfg_dfs_sid, RC_DFS_SID, d->num_dfs_sids); 216 if (ret) 217 return ret; 218 219 ret = rc_write_cfg(qrc, d->cfg_link_sid, RC_LINK_SID, d->num_link_sids); 220 if (ret) 221 return ret; 222 223 /* Everything is ready! Enable the ramp up/down control */ 224 return rc_ramp_ctrl_enable(qrc); 225 } 226 227 static const struct regmap_config qrc_regmap_config = { 228 .reg_bits = 32, 229 .reg_stride = 4, 230 .val_bits = 32, 231 .max_register = 0x68, 232 .fast_io = true, 233 }; 234 235 static const struct reg_sequence msm8976_cfg_dfs_sid[] = { 236 { 0x10, 0xfefebff7 }, 237 { 0x14, 0xfdff7fef }, 238 { 0x18, 0xfbffdefb }, 239 { 0x1c, 0xb69b5555 }, 240 { 0x20, 0x24929249 }, 241 { 0x24, 0x49241112 }, 242 { 0x28, 0x11112111 }, 243 { 0x2c, 0x8102 } 244 }; 245 246 static const struct reg_sequence msm8976_cfg_link_sid[] = { 247 { 0x40, 0xfc987 } 248 }; 249 250 static const struct reg_sequence msm8976_cfg_lmh_sid[] = { 251 { 0x30, 0x77706db }, 252 { 0x34, 0x5550249 }, 253 { 0x38, 0x111 } 254 }; 255 256 static const struct reg_sequence msm8976_cfg_ramp_en[] = { 257 { 0x50, 0x800 }, /* pre_en */ 258 { 0x50, 0xc00 }, /* en */ 259 { 0x50, 0x400 } /* post_en */ 260 }; 261 262 static const struct reg_sequence msm8976_cfg_ramp_dis[] = { 263 { 0x50, 0x0 } 264 }; 265 266 static const struct qcom_ramp_controller_desc msm8976_rc_cfg = { 267 .cfg_dfs_sid = msm8976_cfg_dfs_sid, 268 .num_dfs_sids = ARRAY_SIZE(msm8976_cfg_dfs_sid), 269 270 .cfg_link_sid = msm8976_cfg_link_sid, 271 .num_link_sids = ARRAY_SIZE(msm8976_cfg_link_sid), 272 273 .cfg_lmh_sid = msm8976_cfg_lmh_sid, 274 .num_lmh_sids = ARRAY_SIZE(msm8976_cfg_lmh_sid), 275 276 .cfg_ramp_en = msm8976_cfg_ramp_en, 277 .num_ramp_en = ARRAY_SIZE(msm8976_cfg_ramp_en), 278 279 .cfg_ramp_dis = msm8976_cfg_ramp_dis, 280 .num_ramp_dis = ARRAY_SIZE(msm8976_cfg_ramp_dis), 281 282 .cmd_reg = 0x0, 283 }; 284 285 static int qcom_ramp_controller_probe(struct platform_device *pdev) 286 { 287 struct qcom_ramp_controller *qrc; 288 void __iomem *base; 289 290 base = devm_platform_ioremap_resource(pdev, 0); 291 if (IS_ERR(base)) 292 return PTR_ERR(base); 293 294 qrc = devm_kmalloc(&pdev->dev, sizeof(*qrc), GFP_KERNEL); 295 if (!qrc) 296 return -ENOMEM; 297 298 qrc->desc = device_get_match_data(&pdev->dev); 299 if (!qrc->desc) 300 return -EINVAL; 301 302 qrc->regmap = devm_regmap_init_mmio(&pdev->dev, base, &qrc_regmap_config); 303 if (IS_ERR(qrc->regmap)) 304 return PTR_ERR(qrc->regmap); 305 306 platform_set_drvdata(pdev, qrc); 307 308 return qcom_ramp_controller_start(qrc); 309 } 310 311 static void qcom_ramp_controller_remove(struct platform_device *pdev) 312 { 313 struct qcom_ramp_controller *qrc = platform_get_drvdata(pdev); 314 int ret; 315 316 ret = rc_write_cfg(qrc, qrc->desc->cfg_ramp_dis, 317 RC_DCVS_CFG_SID, qrc->desc->num_ramp_dis); 318 if (ret) 319 dev_err(&pdev->dev, "Failed to send disable sequence\n"); 320 } 321 322 static const struct of_device_id qcom_ramp_controller_match_table[] = { 323 { .compatible = "qcom,msm8976-ramp-controller", .data = &msm8976_rc_cfg }, 324 { /* sentinel */ } 325 }; 326 MODULE_DEVICE_TABLE(of, qcom_ramp_controller_match_table); 327 328 static struct platform_driver qcom_ramp_controller_driver = { 329 .driver = { 330 .name = "qcom-ramp-controller", 331 .of_match_table = qcom_ramp_controller_match_table, 332 .suppress_bind_attrs = true, 333 }, 334 .probe = qcom_ramp_controller_probe, 335 .remove_new = qcom_ramp_controller_remove, 336 }; 337 338 static int __init qcom_ramp_controller_init(void) 339 { 340 return platform_driver_register(&qcom_ramp_controller_driver); 341 } 342 arch_initcall(qcom_ramp_controller_init); 343 344 MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>"); 345 MODULE_DESCRIPTION("Qualcomm Ramp Controller driver"); 346 MODULE_LICENSE("GPL"); 347