233 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.4 */5 6#include <linux/cleanup.h>7#include <linux/delay.h>8#include <linux/err.h>9#include <linux/module.h>10#include <linux/of.h>11#include <linux/platform_device.h>12#include <linux/of_platform.h>13#include <linux/regmap.h>14#include <linux/spmi.h>15#include <linux/soc/qcom/qcom-pbs.h>16 17#define PBS_CLIENT_TRIG_CTL 0x4218#define PBS_CLIENT_SW_TRIG_BIT BIT(7)19#define PBS_CLIENT_SCRATCH1 0x5020#define PBS_CLIENT_SCRATCH2 0x5121#define PBS_CLIENT_SCRATCH2_ERROR 0xFF22 23#define RETRIES 200024#define DELAY 110025 26struct pbs_dev {27 struct device *dev;28 struct regmap *regmap;29 struct mutex lock;30 struct device_link *link;31 32 u32 base;33};34 35static int qcom_pbs_wait_for_ack(struct pbs_dev *pbs, u8 bit_pos)36{37 unsigned int val;38 int ret;39 40 ret = regmap_read_poll_timeout(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2,41 val, val & BIT(bit_pos), DELAY, DELAY * RETRIES);42 43 if (ret < 0) {44 dev_err(pbs->dev, "Timeout for PBS ACK/NACK for bit %u\n", bit_pos);45 return -ETIMEDOUT;46 }47 48 if (val == PBS_CLIENT_SCRATCH2_ERROR) {49 ret = regmap_write(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, 0);50 dev_err(pbs->dev, "NACK from PBS for bit %u\n", bit_pos);51 return -EINVAL;52 }53 54 dev_dbg(pbs->dev, "PBS sequence for bit %u executed!\n", bit_pos);55 return 0;56}57 58/**59 * qcom_pbs_trigger_event() - Trigger the PBS RAM sequence60 * @pbs: Pointer to PBS device61 * @bitmap: bitmap62 *63 * This function is used to trigger the PBS RAM sequence to be64 * executed by the client driver.65 *66 * The PBS trigger sequence involves67 * 1. setting the PBS sequence bit in PBS_CLIENT_SCRATCH168 * 2. Initiating the SW PBS trigger69 * 3. Checking the equivalent bit in PBS_CLIENT_SCRATCH2 for the70 * completion of the sequence.71 * 4. If PBS_CLIENT_SCRATCH2 == 0xFF, the PBS sequence failed to execute72 *73 * Return: 0 on success, < 0 on failure74 */75int qcom_pbs_trigger_event(struct pbs_dev *pbs, u8 bitmap)76{77 unsigned int val;78 u16 bit_pos;79 int ret;80 81 if (WARN_ON(!bitmap))82 return -EINVAL;83 84 if (IS_ERR_OR_NULL(pbs))85 return -EINVAL;86 87 mutex_lock(&pbs->lock);88 ret = regmap_read(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, &val);89 if (ret < 0)90 goto out;91 92 if (val == PBS_CLIENT_SCRATCH2_ERROR) {93 /* PBS error - clear SCRATCH2 register */94 ret = regmap_write(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, 0);95 if (ret < 0)96 goto out;97 }98 99 for (bit_pos = 0; bit_pos < 8; bit_pos++) {100 if (!(bitmap & BIT(bit_pos)))101 continue;102 103 /* Clear the PBS sequence bit position */104 ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2,105 BIT(bit_pos), 0);106 if (ret < 0)107 goto out_clear_scratch1;108 109 /* Set the PBS sequence bit position */110 ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1,111 BIT(bit_pos), BIT(bit_pos));112 if (ret < 0)113 goto out_clear_scratch1;114 115 /* Initiate the SW trigger */116 ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_TRIG_CTL,117 PBS_CLIENT_SW_TRIG_BIT, PBS_CLIENT_SW_TRIG_BIT);118 if (ret < 0)119 goto out_clear_scratch1;120 121 ret = qcom_pbs_wait_for_ack(pbs, bit_pos);122 if (ret < 0)123 goto out_clear_scratch1;124 125 /* Clear the PBS sequence bit position */126 regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1, BIT(bit_pos), 0);127 regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, BIT(bit_pos), 0);128 }129 130out_clear_scratch1:131 /* Clear all the requested bitmap */132 ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1, bitmap, 0);133 134out:135 mutex_unlock(&pbs->lock);136 137 return ret;138}139EXPORT_SYMBOL_GPL(qcom_pbs_trigger_event);140 141/**142 * get_pbs_client_device() - Get the PBS device used by client143 * @dev: Client device144 *145 * This function is used to get the PBS device that is being146 * used by the client.147 *148 * Return: pbs_dev on success, ERR_PTR on failure149 */150struct pbs_dev *get_pbs_client_device(struct device *dev)151{152 struct platform_device *pdev;153 struct pbs_dev *pbs;154 155 struct device_node *pbs_dev_node __free(device_node) = of_parse_phandle(dev->of_node,156 "qcom,pbs", 0);157 if (!pbs_dev_node) {158 dev_err(dev, "Missing qcom,pbs property\n");159 return ERR_PTR(-ENODEV);160 }161 162 pdev = of_find_device_by_node(pbs_dev_node);163 if (!pdev) {164 dev_err(dev, "Unable to find PBS dev_node\n");165 return ERR_PTR(-EPROBE_DEFER);166 }167 168 pbs = platform_get_drvdata(pdev);169 if (!pbs) {170 dev_err(dev, "Cannot get pbs instance from %s\n", dev_name(&pdev->dev));171 platform_device_put(pdev);172 return ERR_PTR(-EPROBE_DEFER);173 }174 175 pbs->link = device_link_add(dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);176 if (!pbs->link) {177 dev_err(&pdev->dev, "Failed to create device link to consumer %s\n", dev_name(dev));178 platform_device_put(pdev);179 return ERR_PTR(-EINVAL);180 }181 182 return pbs;183}184EXPORT_SYMBOL_GPL(get_pbs_client_device);185 186static int qcom_pbs_probe(struct platform_device *pdev)187{188 struct pbs_dev *pbs;189 u32 val;190 int ret;191 192 pbs = devm_kzalloc(&pdev->dev, sizeof(*pbs), GFP_KERNEL);193 if (!pbs)194 return -ENOMEM;195 196 pbs->dev = &pdev->dev;197 pbs->regmap = dev_get_regmap(pbs->dev->parent, NULL);198 if (!pbs->regmap) {199 dev_err(pbs->dev, "Couldn't get parent's regmap\n");200 return -EINVAL;201 }202 203 ret = device_property_read_u32(pbs->dev, "reg", &val);204 if (ret < 0) {205 dev_err(pbs->dev, "Couldn't find reg, ret = %d\n", ret);206 return ret;207 }208 pbs->base = val;209 mutex_init(&pbs->lock);210 211 platform_set_drvdata(pdev, pbs);212 213 return 0;214}215 216static const struct of_device_id qcom_pbs_match_table[] = {217 { .compatible = "qcom,pbs" },218 {}219};220MODULE_DEVICE_TABLE(of, qcom_pbs_match_table);221 222static struct platform_driver qcom_pbs_driver = {223 .driver = {224 .name = "qcom-pbs",225 .of_match_table = qcom_pbs_match_table,226 },227 .probe = qcom_pbs_probe,228};229module_platform_driver(qcom_pbs_driver)230 231MODULE_DESCRIPTION("QCOM PBS DRIVER");232MODULE_LICENSE("GPL");233