drivers/i2c/busses/i2c-designware-platdrv.c

   1 /*
   2  * Synopsys DesignWare I2C adapter driver (master only).
   3  *
   4  * Based on the TI DAVINCI I2C adapter driver.
   5  *
   6  * Copyright (C) 2006 Texas Instruments.
   7  * Copyright (C) 2007 MontaVista Software Inc.
   8  * Copyright (C) 2009 Provigent Ltd.
   9  *
  10  * ----------------------------------------------------------------------------
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  * ----------------------------------------------------------------------------
  26  *
  27  */
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/delay.h>
  31 #include <linux/i2c.h>
  32 #include <linux/clk.h>
  33 #include <linux/errno.h>
  34 #include <linux/sched.h>
  35 #include <linux/err.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/of.h>
  38 #include <linux/of_i2c.h>
  39 #include <linux/platform_device.h>
  40 #include <linux/pm.h>
  41 #include <linux/pm_runtime.h>
  42 #include <linux/io.h>
  43 #include <linux/slab.h>
  44 #include <linux/acpi.h>
  45 #include "i2c-designware-core.h"
  46
  47 static struct i2c_algorithm i2c_dw_algo = {
  48         .master_xfer    = i2c_dw_xfer,
  49         .functionality  = i2c_dw_func,
  50 };
  51 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  52 {
  53         return clk_get_rate(dev->clk)/1000;
  54 }
  55
  56 #ifdef CONFIG_ACPI
  57 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  58 {
  59         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  60
  61         if (!ACPI_HANDLE(&pdev->dev))
  62                 return -ENODEV;
  63
  64         dev->adapter.nr = -1;
  65         dev->tx_fifo_depth = 32;
  66         dev->rx_fifo_depth = 32;
  67         return 0;
  68 }
  69
  70 static const struct acpi_device_id dw_i2c_acpi_match[] = {
  71         { "INT33C2", 0 },
  72         { "INT33C3", 0 },
  73         { "80860F41", 0 },
  74         { }
  75 };
  76 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
  77 #else
  78 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
  79 {
  80         return -ENODEV;
  81 }
  82 #endif
  83
  84 static int dw_i2c_probe(struct platform_device *pdev)
  85 {
  86         struct dw_i2c_dev *dev;
  87         struct i2c_adapter *adap;
  88         struct resource *mem;
  89         int irq, r;
  90
  91         irq = platform_get_irq(pdev, 0);
  92         if (irq < 0) {
  93                 dev_err(&pdev->dev, "no irq resource?\n");
  94                 return irq; /* -ENXIO */
  95         }
  96
  97         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
  98         if (!dev)
  99                 return -ENOMEM;
 100
 101         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 102         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 103         if (IS_ERR(dev->base))
 104                 return PTR_ERR(dev->base);
 105
 106         init_completion(&dev->cmd_complete);
 107         mutex_init(&dev->lock);
 108         dev->dev = &pdev->dev;
 109         dev->irq = irq;
 110         platform_set_drvdata(pdev, dev);
 111
 112         dev->clk = devm_clk_get(&pdev->dev, NULL);
 113         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 114
 115         if (IS_ERR(dev->clk))
 116                 return PTR_ERR(dev->clk);
 117         clk_prepare_enable(dev->clk);
 118
 119         if (pdev->dev.of_node) {
 120                 u32 ht = 0;
 121                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 122
 123                 of_property_read_u32(pdev->dev.of_node,
 124                                         "i2c-sda-hold-time-ns", &ht);
 125                 dev->sda_hold_time = ((u64)ic_clk * ht + 500000) / 1000000;
 126         }
 127
 128         dev->functionality =
 129                 I2C_FUNC_I2C |
 130                 I2C_FUNC_10BIT_ADDR |
 131                 I2C_FUNC_SMBUS_BYTE |
 132                 I2C_FUNC_SMBUS_BYTE_DATA |
 133                 I2C_FUNC_SMBUS_WORD_DATA |
 134                 I2C_FUNC_SMBUS_I2C_BLOCK;
 135         dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 136                 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 137
 138         /* Try first if we can configure the device from ACPI */
 139         r = dw_i2c_acpi_configure(pdev);
 140         if (r) {
 141                 u32 param1 = i2c_dw_read_comp_param(dev);
 142
 143                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 144                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 145                 dev->adapter.nr = pdev->id;
 146         }
 147         r = i2c_dw_init(dev);
 148         if (r)
 149                 return r;
 150
 151         i2c_dw_disable_int(dev);
 152         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
 153                         pdev->name, dev);
 154         if (r) {
 155                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 156                 return r;
 157         }
 158
 159         adap = &dev->adapter;
 160         i2c_set_adapdata(adap, dev);
 161         adap->owner = THIS_MODULE;
 162         adap->class = I2C_CLASS_HWMON;
 163         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 164                         sizeof(adap->name));
 165         adap->algo = &i2c_dw_algo;
 166         adap->dev.parent = &pdev->dev;
 167         adap->dev.of_node = pdev->dev.of_node;
 168
 169         r = i2c_add_numbered_adapter(adap);
 170         if (r) {
 171                 dev_err(&pdev->dev, "failure adding adapter\n");
 172                 return r;
 173         }
 174         of_i2c_register_devices(adap);
 175         acpi_i2c_register_devices(adap);
 176
 177         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 178         pm_runtime_use_autosuspend(&pdev->dev);
 179         pm_runtime_set_active(&pdev->dev);
 180         pm_runtime_enable(&pdev->dev);
 181
 182         return 0;
 183 }
 184
 185 static int dw_i2c_remove(struct platform_device *pdev)
 186 {
 187         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 188
 189         pm_runtime_get_sync(&pdev->dev);
 190
 191         i2c_del_adapter(&dev->adapter);
 192
 193         i2c_dw_disable(dev);
 194
 195         pm_runtime_put(&pdev->dev);
 196         pm_runtime_disable(&pdev->dev);
 197
 198         return 0;
 199 }
 200
 201 #ifdef CONFIG_OF
 202 static const struct of_device_id dw_i2c_of_match[] = {
 203         { .compatible = "snps,designware-i2c", },
 204         {},
 205 };
 206 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 207 #endif
 208
 209 #ifdef CONFIG_PM
 210 static int dw_i2c_suspend(struct device *dev)
 211 {
 212         struct platform_device *pdev = to_platform_device(dev);
 213         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 214
 215         clk_disable_unprepare(i_dev->clk);
 216
 217         return 0;
 218 }
 219
 220 static int dw_i2c_resume(struct device *dev)
 221 {
 222         struct platform_device *pdev = to_platform_device(dev);
 223         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 224
 225         clk_prepare_enable(i_dev->clk);
 226         i2c_dw_init(i_dev);
 227
 228         return 0;
 229 }
 230 #endif
 231
 232 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
 233
 234 /* work with hotplug and coldplug */
 235 MODULE_ALIAS("platform:i2c_designware");
 236
 237 static struct platform_driver dw_i2c_driver = {
 238         .remove         = dw_i2c_remove,
 239         .driver         = {
 240                 .name   = "i2c_designware",
 241                 .owner  = THIS_MODULE,
 242                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 243                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 244                 .pm     = &dw_i2c_dev_pm_ops,
 245         },
 246 };
 247
 248 static int __init dw_i2c_init_driver(void)
 249 {
 250         return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
 251 }
 252 subsys_initcall(dw_i2c_init_driver);
 253
 254 static void __exit dw_i2c_exit_driver(void)
 255 {
 256         platform_driver_unregister(&dw_i2c_driver);
 257 }
 258 module_exit(dw_i2c_exit_driver);
 259
 260 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 261 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 262 MODULE_LICENSE("GPL");