1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * i2c_pca_platform.c 4 * 5 * Platform driver for the PCA9564 I2C controller. 6 * 7 * Copyright (C) 2008 Pengutronix 8 * 9 10 */ 11#include <linux/kernel.h> 12#include <linux/module.h> 13#include <linux/slab.h> 14#include <linux/delay.h> 15#include <linux/jiffies.h> 16#include <linux/errno.h> 17#include <linux/i2c.h> 18#include <linux/interrupt.h> 19#include <linux/platform_device.h> 20#include <linux/i2c-algo-pca.h> 21#include <linux/platform_data/i2c-pca-platform.h> 22#include <linux/gpio/consumer.h> 23#include <linux/io.h> 24#include <linux/of.h> 25 26#include <asm/irq.h> 27 28struct i2c_pca_pf_data { 29 void __iomem *reg_base; 30 int irq; /* if 0, use polling */ 31 struct gpio_desc *gpio; 32 wait_queue_head_t wait; 33 struct i2c_adapter adap; 34 struct i2c_algo_pca_data algo_data; 35}; 36 37/* Read/Write functions for different register alignments */ 38 39static int i2c_pca_pf_readbyte8(void *pd, int reg) 40{ 41 struct i2c_pca_pf_data *i2c = pd; 42 return ioread8(i2c->reg_base + reg); 43} 44 45static int i2c_pca_pf_readbyte16(void *pd, int reg) 46{ 47 struct i2c_pca_pf_data *i2c = pd; 48 return ioread8(i2c->reg_base + reg * 2); 49} 50 51static int i2c_pca_pf_readbyte32(void *pd, int reg) 52{ 53 struct i2c_pca_pf_data *i2c = pd; 54 return ioread8(i2c->reg_base + reg * 4); 55} 56 57static void i2c_pca_pf_writebyte8(void *pd, int reg, int val) 58{ 59 struct i2c_pca_pf_data *i2c = pd; 60 iowrite8(val, i2c->reg_base + reg); 61} 62 63static void i2c_pca_pf_writebyte16(void *pd, int reg, int val) 64{ 65 struct i2c_pca_pf_data *i2c = pd; 66 iowrite8(val, i2c->reg_base + reg * 2); 67} 68 69static void i2c_pca_pf_writebyte32(void *pd, int reg, int val) 70{ 71 struct i2c_pca_pf_data *i2c = pd; 72 iowrite8(val, i2c->reg_base + reg * 4); 73} 74 75 76static int i2c_pca_pf_waitforcompletion(void *pd) 77{ 78 struct i2c_pca_pf_data *i2c = pd; 79 unsigned long timeout; 80 long ret; 81 82 if (i2c->irq) { 83 ret = wait_event_timeout(i2c->wait, 84 i2c->algo_data.read_byte(i2c, I2C_PCA_CON) 85 & I2C_PCA_CON_SI, i2c->adap.timeout); 86 } else { 87 /* Do polling */ 88 timeout = jiffies + i2c->adap.timeout; 89 do { 90 ret = time_before(jiffies, timeout); 91 if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON) 92 & I2C_PCA_CON_SI) 93 break; 94 udelay(100); 95 } while (ret); 96 } 97 98 return ret > 0; 99} 100 101static void i2c_pca_pf_dummyreset(void *pd) 102{ 103 struct i2c_pca_pf_data *i2c = pd; 104 105 dev_warn(&i2c->adap.dev, "No reset-pin found. Chip may get stuck!\n"); 106} 107 108static void i2c_pca_pf_resetchip(void *pd) 109{ 110 struct i2c_pca_pf_data *i2c = pd; 111 112 gpiod_set_value(i2c->gpio, 1); 113 ndelay(100); 114 gpiod_set_value(i2c->gpio, 0); 115} 116 117static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id) 118{ 119 struct i2c_pca_pf_data *i2c = dev_id; 120 121 if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) 122 return IRQ_NONE; 123 124 wake_up(&i2c->wait); 125 126 return IRQ_HANDLED; 127} 128 129 130static int i2c_pca_pf_probe(struct platform_device *pdev) 131{ 132 struct i2c_pca_pf_data *i2c; 133 struct resource *res; 134 struct i2c_pca9564_pf_platform_data *platform_data = 135 dev_get_platdata(&pdev->dev); 136 struct device_node *np = pdev->dev.of_node; 137 int ret = 0; 138 int irq; 139 140 irq = platform_get_irq_optional(pdev, 0); 141 /* If irq is 0, we do polling. */ 142 if (irq < 0) 143 irq = 0; 144 145 i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); 146 if (!i2c) 147 return -ENOMEM; 148 149 i2c->reg_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 150 if (IS_ERR(i2c->reg_base)) 151 return PTR_ERR(i2c->reg_base); 152 153 154 init_waitqueue_head(&i2c->wait); 155 156 i2c->irq = irq; 157 158 i2c->adap.nr = pdev->id; 159 i2c->adap.owner = THIS_MODULE; 160 snprintf(i2c->adap.name, sizeof(i2c->adap.name), 161 "PCA9564/PCA9665 at 0x%08lx", 162 (unsigned long) res->start); 163 i2c->adap.algo_data = &i2c->algo_data; 164 i2c->adap.dev.parent = &pdev->dev; 165 i2c->adap.dev.of_node = np; 166 167 i2c->gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW); 168 if (IS_ERR(i2c->gpio)) 169 return PTR_ERR(i2c->gpio); 170 171 i2c->adap.timeout = HZ; 172 ret = device_property_read_u32(&pdev->dev, "clock-frequency", 173 &i2c->algo_data.i2c_clock); 174 if (ret) 175 i2c->algo_data.i2c_clock = 59000; 176 177 if (platform_data) { 178 i2c->adap.timeout = platform_data->timeout; 179 i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed; 180 } 181 182 i2c->algo_data.data = i2c; 183 i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; 184 if (i2c->gpio) 185 i2c->algo_data.reset_chip = i2c_pca_pf_resetchip; 186 else 187 i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset; 188 189 switch (res->flags & IORESOURCE_MEM_TYPE_MASK) { 190 case IORESOURCE_MEM_32BIT: 191 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32; 192 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32; 193 break; 194 case IORESOURCE_MEM_16BIT: 195 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16; 196 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16; 197 break; 198 case IORESOURCE_MEM_8BIT: 199 default: 200 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8; 201 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8; 202 break; 203 } 204 205 if (irq) { 206 ret = devm_request_irq(&pdev->dev, irq, i2c_pca_pf_handler, 207 IRQF_TRIGGER_FALLING, pdev->name, i2c); 208 if (ret) 209 return ret; 210 } 211 212 ret = i2c_pca_add_numbered_bus(&i2c->adap); 213 if (ret) 214 return ret; 215 216 platform_set_drvdata(pdev, i2c); 217 218 dev_info(&pdev->dev, "registered.\n"); 219 220 return 0; 221} 222 223static void i2c_pca_pf_remove(struct platform_device *pdev) 224{ 225 struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev); 226 227 i2c_del_adapter(&i2c->adap); 228} 229 230#ifdef CONFIG_OF 231static const struct of_device_id i2c_pca_of_match_table[] = { 232 { .compatible = "nxp,pca9564" }, 233 { .compatible = "nxp,pca9665" }, 234 {}, 235}; 236MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table); 237#endif 238 239static struct platform_driver i2c_pca_pf_driver = { 240 .probe = i2c_pca_pf_probe, 241 .remove_new = i2c_pca_pf_remove, 242 .driver = { 243 .name = "i2c-pca-platform", 244 .of_match_table = of_match_ptr(i2c_pca_of_match_table), 245 }, 246}; 247 248module_platform_driver(i2c_pca_pf_driver); 249 250MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>"); 251MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); 252MODULE_LICENSE("GPL"); 253