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
  26 #include <asm/irq.h>
  27
  28 struct 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
  39 static 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
  45 static 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
  51 static 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
  57 static 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
  63 static 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
  69 static 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
  76 static 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
 101 static 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
 108 static 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
 117 static 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
 130 static 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
 223 static 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
 231 static const struct of_device_id i2c_pca_of_match_table[] = {
 232         { .compatible = "nxp,pca9564" },
 233         { .compatible = "nxp,pca9665" },
 234         {},
 235 };
 236 MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table);
 237 #endif
 238
 239 static 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
 248 module_platform_driver(i2c_pca_pf_driver);
 249
 250 MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
 251 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
 252 MODULE_LICENSE("GPL");