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 #include <linux/of_device.h> 26 27 #include <asm/irq.h> 28 29 struct i2c_pca_pf_data { 30 void __iomem *reg_base; 31 int irq; /* if 0, use polling */ 32 struct gpio_desc *gpio; 33 wait_queue_head_t wait; 34 struct i2c_adapter adap; 35 struct i2c_algo_pca_data algo_data; 36 }; 37 38 /* Read/Write functions for different register alignments */ 39 40 static int i2c_pca_pf_readbyte8(void *pd, int reg) 41 { 42 struct i2c_pca_pf_data *i2c = pd; 43 return ioread8(i2c->reg_base + reg); 44 } 45 46 static int i2c_pca_pf_readbyte16(void *pd, int reg) 47 { 48 struct i2c_pca_pf_data *i2c = pd; 49 return ioread8(i2c->reg_base + reg * 2); 50 } 51 52 static int i2c_pca_pf_readbyte32(void *pd, int reg) 53 { 54 struct i2c_pca_pf_data *i2c = pd; 55 return ioread8(i2c->reg_base + reg * 4); 56 } 57 58 static void i2c_pca_pf_writebyte8(void *pd, int reg, int val) 59 { 60 struct i2c_pca_pf_data *i2c = pd; 61 iowrite8(val, i2c->reg_base + reg); 62 } 63 64 static void i2c_pca_pf_writebyte16(void *pd, int reg, int val) 65 { 66 struct i2c_pca_pf_data *i2c = pd; 67 iowrite8(val, i2c->reg_base + reg * 2); 68 } 69 70 static void i2c_pca_pf_writebyte32(void *pd, int reg, int val) 71 { 72 struct i2c_pca_pf_data *i2c = pd; 73 iowrite8(val, i2c->reg_base + reg * 4); 74 } 75 76 77 static int i2c_pca_pf_waitforcompletion(void *pd) 78 { 79 struct i2c_pca_pf_data *i2c = pd; 80 unsigned long timeout; 81 long ret; 82 83 if (i2c->irq) { 84 ret = wait_event_timeout(i2c->wait, 85 i2c->algo_data.read_byte(i2c, I2C_PCA_CON) 86 & I2C_PCA_CON_SI, i2c->adap.timeout); 87 } else { 88 /* Do polling */ 89 timeout = jiffies + i2c->adap.timeout; 90 do { 91 ret = time_before(jiffies, timeout); 92 if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON) 93 & I2C_PCA_CON_SI) 94 break; 95 udelay(100); 96 } while (ret); 97 } 98 99 return ret > 0; 100 } 101 102 static void i2c_pca_pf_dummyreset(void *pd) 103 { 104 struct i2c_pca_pf_data *i2c = pd; 105 106 dev_warn(&i2c->adap.dev, "No reset-pin found. Chip may get stuck!\n"); 107 } 108 109 static void i2c_pca_pf_resetchip(void *pd) 110 { 111 struct i2c_pca_pf_data *i2c = pd; 112 113 gpiod_set_value(i2c->gpio, 1); 114 ndelay(100); 115 gpiod_set_value(i2c->gpio, 0); 116 } 117 118 static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id) 119 { 120 struct i2c_pca_pf_data *i2c = dev_id; 121 122 if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) 123 return IRQ_NONE; 124 125 wake_up(&i2c->wait); 126 127 return IRQ_HANDLED; 128 } 129 130 131 static int i2c_pca_pf_probe(struct platform_device *pdev) 132 { 133 struct i2c_pca_pf_data *i2c; 134 struct resource *res; 135 struct i2c_pca9564_pf_platform_data *platform_data = 136 dev_get_platdata(&pdev->dev); 137 struct device_node *np = pdev->dev.of_node; 138 int ret = 0; 139 int irq; 140 141 irq = platform_get_irq_optional(pdev, 0); 142 /* If irq is 0, we do polling. */ 143 if (irq < 0) 144 irq = 0; 145 146 i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); 147 if (!i2c) 148 return -ENOMEM; 149 150 i2c->reg_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 151 if (IS_ERR(i2c->reg_base)) 152 return PTR_ERR(i2c->reg_base); 153 154 155 init_waitqueue_head(&i2c->wait); 156 157 i2c->irq = irq; 158 159 i2c->adap.nr = pdev->id; 160 i2c->adap.owner = THIS_MODULE; 161 snprintf(i2c->adap.name, sizeof(i2c->adap.name), 162 "PCA9564/PCA9665 at 0x%08lx", 163 (unsigned long) res->start); 164 i2c->adap.algo_data = &i2c->algo_data; 165 i2c->adap.dev.parent = &pdev->dev; 166 i2c->adap.dev.of_node = np; 167 168 i2c->gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW); 169 if (IS_ERR(i2c->gpio)) 170 return PTR_ERR(i2c->gpio); 171 172 i2c->adap.timeout = HZ; 173 ret = device_property_read_u32(&pdev->dev, "clock-frequency", 174 &i2c->algo_data.i2c_clock); 175 if (ret) 176 i2c->algo_data.i2c_clock = 59000; 177 178 if (platform_data) { 179 i2c->adap.timeout = platform_data->timeout; 180 i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed; 181 } 182 183 i2c->algo_data.data = i2c; 184 i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; 185 if (i2c->gpio) 186 i2c->algo_data.reset_chip = i2c_pca_pf_resetchip; 187 else 188 i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset; 189 190 switch (res->flags & IORESOURCE_MEM_TYPE_MASK) { 191 case IORESOURCE_MEM_32BIT: 192 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32; 193 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32; 194 break; 195 case IORESOURCE_MEM_16BIT: 196 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16; 197 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16; 198 break; 199 case IORESOURCE_MEM_8BIT: 200 default: 201 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8; 202 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8; 203 break; 204 } 205 206 if (irq) { 207 ret = devm_request_irq(&pdev->dev, irq, i2c_pca_pf_handler, 208 IRQF_TRIGGER_FALLING, pdev->name, i2c); 209 if (ret) 210 return ret; 211 } 212 213 ret = i2c_pca_add_numbered_bus(&i2c->adap); 214 if (ret) 215 return ret; 216 217 platform_set_drvdata(pdev, i2c); 218 219 dev_info(&pdev->dev, "registered.\n"); 220 221 return 0; 222 } 223 224 static int i2c_pca_pf_remove(struct platform_device *pdev) 225 { 226 struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev); 227 228 i2c_del_adapter(&i2c->adap); 229 230 return 0; 231 } 232 233 #ifdef CONFIG_OF 234 static const struct of_device_id i2c_pca_of_match_table[] = { 235 { .compatible = "nxp,pca9564" }, 236 { .compatible = "nxp,pca9665" }, 237 {}, 238 }; 239 MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table); 240 #endif 241 242 static struct platform_driver i2c_pca_pf_driver = { 243 .probe = i2c_pca_pf_probe, 244 .remove = i2c_pca_pf_remove, 245 .driver = { 246 .name = "i2c-pca-platform", 247 .of_match_table = of_match_ptr(i2c_pca_of_match_table), 248 }, 249 }; 250 251 module_platform_driver(i2c_pca_pf_driver); 252 253 MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>"); 254 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); 255 MODULE_LICENSE("GPL"); 256