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 };
  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 void 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
 231 #ifdef CONFIG_OF
 232 static const struct of_device_id i2c_pca_of_match_table[] = {
 233         { .compatible = "nxp,pca9564" },
 234         { .compatible = "nxp,pca9665" },
 235         {},
 236 };
 237 MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table);
 238 #endif
 239
 240 static struct platform_driver i2c_pca_pf_driver = {
 241         .probe = i2c_pca_pf_probe,
 242         .remove_new = i2c_pca_pf_remove,
 243         .driver = {
 244                 .name = "i2c-pca-platform",
 245                 .of_match_table = of_match_ptr(i2c_pca_of_match_table),
 246         },
 247 };
 248
 249 module_platform_driver(i2c_pca_pf_driver);
 250
 251 MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
 252 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
 253 MODULE_LICENSE("GPL");