diff options
Diffstat (limited to 'drivers/soc/qcom/ramp_controller.c')
| -rw-r--r-- | drivers/soc/qcom/ramp_controller.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/drivers/soc/qcom/ramp_controller.c b/drivers/soc/qcom/ramp_controller.c new file mode 100644 index 0000000000..e9a0cca071 --- /dev/null +++ b/drivers/soc/qcom/ramp_controller.c @@ -0,0 +1,346 @@ +// 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"); |