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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * i2c_pca_platform.c4 *5 * Platform driver for the PCA9564 I2C controller.6 *7 * Copyright (C) 2008 Pengutronix8 *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 else187 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_OF231static 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#endif238 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