1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 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 0x42 18 #define PBS_CLIENT_SW_TRIG_BIT BIT(7) 19 #define PBS_CLIENT_SCRATCH1 0x50 20 #define PBS_CLIENT_SCRATCH2 0x51 21 #define PBS_CLIENT_SCRATCH2_ERROR 0xFF 22 23 #define RETRIES 2000 24 #define DELAY 1100 25 26 struct 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 35 static 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 sequence 60 * @pbs: Pointer to PBS device 61 * @bitmap: bitmap 62 * 63 * This function is used to trigger the PBS RAM sequence to be 64 * executed by the client driver. 65 * 66 * The PBS trigger sequence involves 67 * 1. setting the PBS sequence bit in PBS_CLIENT_SCRATCH1 68 * 2. Initiating the SW PBS trigger 69 * 3. Checking the equivalent bit in PBS_CLIENT_SCRATCH2 for the 70 * completion of the sequence. 71 * 4. If PBS_CLIENT_SCRATCH2 == 0xFF, the PBS sequence failed to execute 72 * 73 * Return: 0 on success, < 0 on failure 74 */ 75 int 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 } 129 130 out_clear_scratch1: 131 /* Clear all the requested bitmap */ 132 ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1, bitmap, 0); 133 134 out: 135 mutex_unlock(&pbs->lock); 136 137 return ret; 138 } 139 EXPORT_SYMBOL_GPL(qcom_pbs_trigger_event); 140 141 /** 142 * get_pbs_client_device() - Get the PBS device used by client 143 * @dev: Client device 144 * 145 * This function is used to get the PBS device that is being 146 * used by the client. 147 * 148 * Return: pbs_dev on success, ERR_PTR on failure 149 */ 150 struct 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 } 184 EXPORT_SYMBOL_GPL(get_pbs_client_device); 185 186 static 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 } 215 216 static const struct of_device_id qcom_pbs_match_table[] = { 217 { .compatible = "qcom,pbs" }, 218 {} 219 }; 220 MODULE_DEVICE_TABLE(of, qcom_pbs_match_table); 221 222 static 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 }; 229 module_platform_driver(qcom_pbs_driver) 230 231 MODULE_DESCRIPTION("QCOM PBS DRIVER"); 232 MODULE_LICENSE("GPL"); 233