// SPDX-License-Identifier: GPL-2.0 /* * Qualcomm Ramp Controller driver * Copyright (c) 2022, AngeloGioacchino Del Regno * */ #include #include #include #include #include #include #include #include #define RC_UPDATE_EN BIT(0) #define RC_ROOT_EN BIT(1) #define RC_REG_CFG_UPDATE 0x60 #define RC_CFG_UPDATE_EN BIT(8) #define RC_CFG_ACK GENMASK(31, 16) #define RC_DCVS_CFG_SID 2 #define RC_LINK_SID 3 #define RC_LMH_SID 6 #define RC_DFS_SID 14 #define RC_UPDATE_TIMEOUT_US 500 /** * struct qcom_ramp_controller_desc - SoC specific parameters * @cfg_dfs_sid: Dynamic Frequency Scaling SID configuration * @cfg_link_sid: Link SID configuration * @cfg_lmh_sid: Limits Management hardware SID configuration * @cfg_ramp_en: Ramp Controller enable sequence * @cfg_ramp_dis: Ramp Controller disable sequence * @cmd_reg: Command register offset * @num_dfs_sids: Number of DFS SIDs (max 8) * @num_link_sids: Number of Link SIDs (max 3) * @num_lmh_sids: Number of LMh SIDs (max 8) * @num_ramp_en: Number of entries in enable sequence * @num_ramp_dis: Number of entries in disable sequence */ struct qcom_ramp_controller_desc { const struct reg_sequence *cfg_dfs_sid; const struct reg_sequence *cfg_link_sid; const struct reg_sequence *cfg_lmh_sid; const struct reg_sequence *cfg_ramp_en; const struct reg_sequence *cfg_ramp_dis; u8 cmd_reg; u8 num_dfs_sids; u8 num_link_sids; u8 num_lmh_sids; u8 num_ramp_en; u8 num_ramp_dis; }; /** * struct qcom_ramp_controller - Main driver structure * @regmap: Regmap handle * @desc: SoC specific parameters */ struct qcom_ramp_controller { struct regmap *regmap; const struct qcom_ramp_controller_desc *desc; }; /** * rc_wait_for_update() - Wait for Ramp Controller root update * @qrc: Main driver structure * * Return: Zero for success or negative number for failure */ static int rc_wait_for_update(struct qcom_ramp_controller *qrc) { const struct qcom_ramp_controller_desc *d = qrc->desc; struct regmap *r = qrc->regmap; u32 val; int ret; ret = regmap_set_bits(r, d->cmd_reg, RC_ROOT_EN); if (ret) return ret; return regmap_read_poll_timeout(r, d->cmd_reg, val, !(val & RC_UPDATE_EN), 1, RC_UPDATE_TIMEOUT_US); } /** * rc_set_cfg_update() - Ramp Controller configuration update * @qrc: Main driver structure * @ce: Configuration entry to update * * Return: Zero for success or negative number for failure */ static int rc_set_cfg_update(struct qcom_ramp_controller *qrc, u8 ce) { const struct qcom_ramp_controller_desc *d = qrc->desc; struct regmap *r = qrc->regmap; u32 ack, val; int ret; /* The ack bit is between bits 16-31 of RC_REG_CFG_UPDATE */ ack = FIELD_PREP(RC_CFG_ACK, BIT(ce)); /* Write the configuration type first... */ ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, ce); if (ret) return ret; /* ...and after that, enable the update bit to sync the changes */ ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, RC_CFG_UPDATE_EN); if (ret) return ret; /* Wait for the changes to go through */ ret = regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE, val, val & ack, 1, RC_UPDATE_TIMEOUT_US); if (ret) return ret; /* * Configuration update success! The CFG_UPDATE register will not be * cleared automatically upon applying the configuration, so we have * to do that manually in order to leave the ramp controller in a * predictable and clean state. */ ret = regmap_write(r, d->cmd_reg + RC_REG_CFG_UPDATE, 0); if (ret) return ret; /* Wait for the update bit cleared ack */ return regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE, val, !(val & RC_CFG_ACK), 1, RC_UPDATE_TIMEOUT_US); } /** * rc_write_cfg - Send configuration sequence * @qrc: Main driver structure * @seq: Register sequence to send before asking for update * @ce: Configuration SID * @nsids: Total number of SIDs * * Returns: Zero for success or negative number for error */ static int rc_write_cfg(struct qcom_ramp_controller *qrc, const struct reg_sequence *seq, u16 ce, u8 nsids) { int ret; u8 i; /* Check if, and wait until the ramp controller is ready */ ret = rc_wait_for_update(qrc); if (ret) return ret; /* Write the sequence */ ret = regmap_multi_reg_write(qrc->regmap, seq, nsids); if (ret) return ret; /* Pull the trigger: do config update starting from the last sid */ for (i = 0; i < nsids; i++) { ret = rc_set_cfg_update(qrc, (u8)ce - i); if (ret) return ret; } return 0; } /** * rc_ramp_ctrl_enable() - Enable Ramp up/down Control * @qrc: Main driver structure * * Return: Zero for success or negative number for error */ static int rc_ramp_ctrl_enable(struct qcom_ramp_controller *qrc) { const struct qcom_ramp_controller_desc *d = qrc->desc; int i, ret; for (i = 0; i < d->num_ramp_en; i++) { ret = rc_write_cfg(qrc, &d->cfg_ramp_en[i], RC_DCVS_CFG_SID, 1); if (ret) return ret; } return 0; } /** * qcom_ramp_controller_start() - Initialize and start the ramp controller * @qrc: Main driver structure * * The Ramp Controller needs to be initialized by programming the relevant * registers with SoC-specific configuration: once programming is done, * the hardware will take care of the rest (no further handling required). * * Return: Zero for success or negative number for error */ static int qcom_ramp_controller_start(struct qcom_ramp_controller *qrc) { const struct qcom_ramp_controller_desc *d = qrc->desc; int ret; /* Program LMH, DFS, Link SIDs */ ret = rc_write_cfg(qrc, d->cfg_lmh_sid, RC_LMH_SID, d->num_lmh_sids); if (ret) return ret; ret = rc_write_cfg(qrc, d->cfg_dfs_sid, RC_DFS_SID, d->num_dfs_sids); if (ret) return ret; ret = rc_write_cfg(qrc, d->cfg_link_sid, RC_LINK_SID, d->num_link_sids); if (ret) return ret; /* Everything is ready! Enable the ramp up/down control */ return rc_ramp_ctrl_enable(qrc); } static const struct regmap_config qrc_regmap_config = { .reg_bits = 32, .reg_stride = 4, .val_bits = 32, .max_register = 0x68, .fast_io = true, }; static const struct reg_sequence msm8976_cfg_dfs_sid[] = { { 0x10, 0xfefebff7 }, { 0x14, 0xfdff7fef }, { 0x18, 0xfbffdefb }, { 0x1c, 0xb69b5555 }, { 0x20, 0x24929249 }, { 0x24, 0x49241112 }, { 0x28, 0x11112111 }, { 0x2c, 0x8102 } }; static const struct reg_sequence msm8976_cfg_link_sid[] = { { 0x40, 0xfc987 } }; static const struct reg_sequence msm8976_cfg_lmh_sid[] = { { 0x30, 0x77706db }, { 0x34, 0x5550249 }, { 0x38, 0x111 } }; static const struct reg_sequence msm8976_cfg_ramp_en[] = { { 0x50, 0x800 }, /* pre_en */ { 0x50, 0xc00 }, /* en */ { 0x50, 0x400 } /* post_en */ }; static const struct reg_sequence msm8976_cfg_ramp_dis[] = { { 0x50, 0x0 } }; static const struct qcom_ramp_controller_desc msm8976_rc_cfg = { .cfg_dfs_sid = msm8976_cfg_dfs_sid, .num_dfs_sids = ARRAY_SIZE(msm8976_cfg_dfs_sid), .cfg_link_sid = msm8976_cfg_link_sid, .num_link_sids = ARRAY_SIZE(msm8976_cfg_link_sid), .cfg_lmh_sid = msm8976_cfg_lmh_sid, .num_lmh_sids = ARRAY_SIZE(msm8976_cfg_lmh_sid), .cfg_ramp_en = msm8976_cfg_ramp_en, .num_ramp_en = ARRAY_SIZE(msm8976_cfg_ramp_en), .cfg_ramp_dis = msm8976_cfg_ramp_dis, .num_ramp_dis = ARRAY_SIZE(msm8976_cfg_ramp_dis), .cmd_reg = 0x0, }; static int qcom_ramp_controller_probe(struct platform_device *pdev) { struct qcom_ramp_controller *qrc; void __iomem *base; base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(base)) return PTR_ERR(base); qrc = devm_kmalloc(&pdev->dev, sizeof(*qrc), GFP_KERNEL); if (!qrc) return -ENOMEM; qrc->desc = device_get_match_data(&pdev->dev); if (!qrc->desc) return -EINVAL; qrc->regmap = devm_regmap_init_mmio(&pdev->dev, base, &qrc_regmap_config); if (IS_ERR(qrc->regmap)) return PTR_ERR(qrc->regmap); platform_set_drvdata(pdev, qrc); return qcom_ramp_controller_start(qrc); } static int qcom_ramp_controller_remove(struct platform_device *pdev) { struct qcom_ramp_controller *qrc = platform_get_drvdata(pdev); return rc_write_cfg(qrc, qrc->desc->cfg_ramp_dis, RC_DCVS_CFG_SID, qrc->desc->num_ramp_dis); } static const struct of_device_id qcom_ramp_controller_match_table[] = { { .compatible = "qcom,msm8976-ramp-controller", .data = &msm8976_rc_cfg }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, qcom_ramp_controller_match_table); static struct platform_driver qcom_ramp_controller_driver = { .driver = { .name = "qcom-ramp-controller", .of_match_table = qcom_ramp_controller_match_table, .suppress_bind_attrs = true, }, .probe = qcom_ramp_controller_probe, .remove = qcom_ramp_controller_remove, }; static int __init qcom_ramp_controller_init(void) { return platform_driver_register(&qcom_ramp_controller_driver); } arch_initcall(qcom_ramp_controller_init); MODULE_AUTHOR("AngeloGioacchino Del Regno "); MODULE_DESCRIPTION("Qualcomm Ramp Controller driver"); MODULE_LICENSE("GPL");