drivers/i2c/busses/i2c-pca-platform.c

   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         unsigned long                   io_base;
  37         unsigned long                   io_size;
  38 };
  39
  40 /* Read/Write functions for different register alignments */
  41
  42 static int i2c_pca_pf_readbyte8(void *pd, int reg)
  43 {
  44         struct i2c_pca_pf_data *i2c = pd;
  45         return ioread8(i2c->reg_base + reg);
  46 }
  47
  48 static int i2c_pca_pf_readbyte16(void *pd, int reg)
  49 {
  50         struct i2c_pca_pf_data *i2c = pd;
  51         return ioread8(i2c->reg_base + reg * 2);
  52 }
  53
  54 static int i2c_pca_pf_readbyte32(void *pd, int reg)
  55 {
  56         struct i2c_pca_pf_data *i2c = pd;
  57         return ioread8(i2c->reg_base + reg * 4);
  58 }
  59
  60 static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)
  61 {
  62         struct i2c_pca_pf_data *i2c = pd;
  63         iowrite8(val, i2c->reg_base + reg);
  64 }
  65
  66 static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)
  67 {
  68         struct i2c_pca_pf_data *i2c = pd;
  69         iowrite8(val, i2c->reg_base + reg * 2);
  70 }
  71
  72 static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
  73 {
  74         struct i2c_pca_pf_data *i2c = pd;
  75         iowrite8(val, i2c->reg_base + reg * 4);
  76 }
  77
  78
  79 static int i2c_pca_pf_waitforcompletion(void *pd)
  80 {
  81         struct i2c_pca_pf_data *i2c = pd;
  82         unsigned long timeout;
  83         long ret;
  84
  85         if (i2c->irq) {
  86                 ret = wait_event_timeout(i2c->wait,
  87                         i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
  88                         & I2C_PCA_CON_SI, i2c->adap.timeout);
  89         } else {
  90                 /* Do polling */
  91                 timeout = jiffies + i2c->adap.timeout;
  92                 do {
  93                         ret = time_before(jiffies, timeout);
  94                         if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
  95                                         & I2C_PCA_CON_SI)
  96                                 break;
  97                         udelay(100);
  98                 } while (ret);
  99         }
 100
 101         return ret > 0;
 102 }
 103
 104 static void i2c_pca_pf_dummyreset(void *pd)
 105 {
 106         struct i2c_pca_pf_data *i2c = pd;
 107
 108         dev_warn(&i2c->adap.dev, "No reset-pin found. Chip may get stuck!\n");
 109 }
 110
 111 static void i2c_pca_pf_resetchip(void *pd)
 112 {
 113         struct i2c_pca_pf_data *i2c = pd;
 114
 115         gpiod_set_value(i2c->gpio, 1);
 116         ndelay(100);
 117         gpiod_set_value(i2c->gpio, 0);
 118 }
 119
 120 static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)
 121 {
 122         struct i2c_pca_pf_data *i2c = dev_id;
 123
 124         if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
 125                 return IRQ_NONE;
 126
 127         wake_up(&i2c->wait);
 128
 129         return IRQ_HANDLED;
 130 }
 131
 132
 133 static int i2c_pca_pf_probe(struct platform_device *pdev)
 134 {
 135         struct i2c_pca_pf_data *i2c;
 136         struct resource *res;
 137         struct i2c_pca9564_pf_platform_data *platform_data =
 138                                 dev_get_platdata(&pdev->dev);
 139         struct device_node *np = pdev->dev.of_node;
 140         int ret = 0;
 141         int irq;
 142
 143         irq = platform_get_irq(pdev, 0);
 144         /* If irq is 0, we do polling. */
 145         if (irq < 0)
 146                 irq = 0;
 147
 148         i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
 149         if (!i2c)
 150                 return -ENOMEM;
 151
 152         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 153         i2c->reg_base = devm_ioremap_resource(&pdev->dev, res);
 154         if (IS_ERR(i2c->reg_base))
 155                 return PTR_ERR(i2c->reg_base);
 156
 157
 158         init_waitqueue_head(&i2c->wait);
 159
 160         i2c->io_base = res->start;
 161         i2c->io_size = resource_size(res);
 162         i2c->irq = irq;
 163
 164         i2c->adap.nr = pdev->id;
 165         i2c->adap.owner = THIS_MODULE;
 166         snprintf(i2c->adap.name, sizeof(i2c->adap.name),
 167                  "PCA9564/PCA9665 at 0x%08lx",
 168                  (unsigned long) res->start);
 169         i2c->adap.algo_data = &i2c->algo_data;
 170         i2c->adap.dev.parent = &pdev->dev;
 171         i2c->adap.dev.of_node = np;
 172
 173         i2c->gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
 174         if (IS_ERR(i2c->gpio))
 175                 return PTR_ERR(i2c->gpio);
 176
 177         i2c->adap.timeout = HZ;
 178         ret = device_property_read_u32(&pdev->dev, "clock-frequency",
 179                                        &i2c->algo_data.i2c_clock);
 180         if (ret)
 181                 i2c->algo_data.i2c_clock = 59000;
 182
 183         if (platform_data) {
 184                 i2c->adap.timeout = platform_data->timeout;
 185                 i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
 186         }
 187
 188         i2c->algo_data.data = i2c;
 189         i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
 190         if (i2c->gpio)
 191                 i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
 192         else
 193                 i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
 194
 195         switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
 196         case IORESOURCE_MEM_32BIT:
 197                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;
 198                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;
 199                 break;
 200         case IORESOURCE_MEM_16BIT:
 201                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;
 202                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;
 203                 break;
 204         case IORESOURCE_MEM_8BIT:
 205         default:
 206                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;
 207                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;
 208                 break;
 209         }
 210
 211         if (irq) {
 212                 ret = devm_request_irq(&pdev->dev, irq, i2c_pca_pf_handler,
 213                         IRQF_TRIGGER_FALLING, pdev->name, i2c);
 214                 if (ret)
 215                         return ret;
 216         }
 217
 218         ret = i2c_pca_add_numbered_bus(&i2c->adap);
 219         if (ret)
 220                 return ret;
 221
 222         platform_set_drvdata(pdev, i2c);
 223
 224         dev_info(&pdev->dev, "registered.\n");
 225
 226         return 0;
 227 }
 228
 229 static int i2c_pca_pf_remove(struct platform_device *pdev)
 230 {
 231         struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);
 232
 233         i2c_del_adapter(&i2c->adap);
 234
 235         return 0;
 236 }
 237
 238 #ifdef CONFIG_OF
 239 static const struct of_device_id i2c_pca_of_match_table[] = {
 240         { .compatible = "nxp,pca9564" },
 241         { .compatible = "nxp,pca9665" },
 242         {},
 243 };
 244 MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table);
 245 #endif
 246
 247 static struct platform_driver i2c_pca_pf_driver = {
 248         .probe = i2c_pca_pf_probe,
 249         .remove = i2c_pca_pf_remove,
 250         .driver = {
 251                 .name = "i2c-pca-platform",
 252                 .of_match_table = of_match_ptr(i2c_pca_of_match_table),
 253         },
 254 };
 255
 256 module_platform_driver(i2c_pca_pf_driver);
 257
 258 MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
 259 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
 260 MODULE_LICENSE("GPL");