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 guard(mutex)(&pbs->lock); 88 ret = regmap_read(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, &val); 89 if (ret < 0) 90 return ret; 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 return ret; 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 break; 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 break; 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 break; 120 121 ret = qcom_pbs_wait_for_ack(pbs, bit_pos); 122 if (ret < 0) 123 break; 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 /* Clear all the requested bitmap */ 131 return regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1, bitmap, 0); 132 } 133 EXPORT_SYMBOL_GPL(qcom_pbs_trigger_event); 134 135 /** 136 * get_pbs_client_device() - Get the PBS device used by client 137 * @dev: Client device 138 * 139 * This function is used to get the PBS device that is being 140 * used by the client. 141 * 142 * Return: pbs_dev on success, ERR_PTR on failure 143 */ 144 struct pbs_dev *get_pbs_client_device(struct device *dev) 145 { 146 struct platform_device *pdev; 147 struct pbs_dev *pbs; 148 149 struct device_node *pbs_dev_node __free(device_node) = of_parse_phandle(dev->of_node, 150 "qcom,pbs", 0); 151 if (!pbs_dev_node) { 152 dev_err(dev, "Missing qcom,pbs property\n"); 153 return ERR_PTR(-ENODEV); 154 } 155 156 pdev = of_find_device_by_node(pbs_dev_node); 157 if (!pdev) { 158 dev_err(dev, "Unable to find PBS dev_node\n"); 159 return ERR_PTR(-EPROBE_DEFER); 160 } 161 162 pbs = platform_get_drvdata(pdev); 163 if (!pbs) { 164 dev_err(dev, "Cannot get pbs instance from %s\n", dev_name(&pdev->dev)); 165 platform_device_put(pdev); 166 return ERR_PTR(-EPROBE_DEFER); 167 } 168 169 pbs->link = device_link_add(dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER); 170 if (!pbs->link) { 171 dev_err(&pdev->dev, "Failed to create device link to consumer %s\n", dev_name(dev)); 172 platform_device_put(pdev); 173 return ERR_PTR(-EINVAL); 174 } 175 176 return pbs; 177 } 178 EXPORT_SYMBOL_GPL(get_pbs_client_device); 179 180 static int qcom_pbs_probe(struct platform_device *pdev) 181 { 182 struct pbs_dev *pbs; 183 u32 val; 184 int ret; 185 186 pbs = devm_kzalloc(&pdev->dev, sizeof(*pbs), GFP_KERNEL); 187 if (!pbs) 188 return -ENOMEM; 189 190 pbs->dev = &pdev->dev; 191 pbs->regmap = dev_get_regmap(pbs->dev->parent, NULL); 192 if (!pbs->regmap) { 193 dev_err(pbs->dev, "Couldn't get parent's regmap\n"); 194 return -EINVAL; 195 } 196 197 ret = device_property_read_u32(pbs->dev, "reg", &val); 198 if (ret < 0) { 199 dev_err(pbs->dev, "Couldn't find reg, ret = %d\n", ret); 200 return ret; 201 } 202 pbs->base = val; 203 mutex_init(&pbs->lock); 204 205 platform_set_drvdata(pdev, pbs); 206 207 return 0; 208 } 209 210 static const struct of_device_id qcom_pbs_match_table[] = { 211 { .compatible = "qcom,pbs" }, 212 {} 213 }; 214 MODULE_DEVICE_TABLE(of, qcom_pbs_match_table); 215 216 static struct platform_driver qcom_pbs_driver = { 217 .driver = { 218 .name = "qcom-pbs", 219 .of_match_table = qcom_pbs_match_table, 220 }, 221 .probe = qcom_pbs_probe, 222 }; 223 module_platform_driver(qcom_pbs_driver) 224 225 MODULE_DESCRIPTION("QCOM PBS DRIVER"); 226 MODULE_LICENSE("GPL"); 227