| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Qualcomm Ramp Controller driver |
| * Copyright (c) 2022, AngeloGioacchino Del Regno |
| * <angelogioacchino.delregno@collabora.com> |
| */ |
| |
| #include <linux/bitfield.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/of_platform.h> |
| #include <linux/platform_device.h> |
| #include <linux/regmap.h> |
| #include <linux/types.h> |
| |
| #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 void qcom_ramp_controller_remove(struct platform_device *pdev) |
| { |
| struct qcom_ramp_controller *qrc = platform_get_drvdata(pdev); |
| int ret; |
| |
| ret = rc_write_cfg(qrc, qrc->desc->cfg_ramp_dis, |
| RC_DCVS_CFG_SID, qrc->desc->num_ramp_dis); |
| if (ret) |
| dev_err(&pdev->dev, "Failed to send disable sequence\n"); |
| } |
| |
| 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_new = 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 <angelogioacchino.delregno@collabora.com>"); |
| MODULE_DESCRIPTION("Qualcomm Ramp Controller driver"); |
| MODULE_LICENSE("GPL"); |