target/linux/ramips/patches-3.8/0066-i2c-MIPS-adds-ralink-I2C-driver.patch

   1 From 68fc18202484e98861ef7eed2a78b64b16c73db9 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Mon, 29 Apr 2013 14:40:43 +0200
   4 Subject: [PATCH 66/79] i2c: MIPS: adds ralink I2C driver
   5
   6 Signed-off-by: John Crispin <blogic@openwrt.org>
   7 ---
   8  .../devicetree/bindings/i2c/i2c-ralink.txt         |   27 ++
   9  drivers/i2c/busses/Kconfig                         |    4 +
  10  drivers/i2c/busses/Makefile                        |    1 +
  11  drivers/i2c/busses/i2c-ralink.c                    |  274 ++++++++++++++++++++
  12  4 files changed, 306 insertions(+)
  13  create mode 100644 Documentation/devicetree/bindings/i2c/i2c-ralink.txt
  14  create mode 100644 drivers/i2c/busses/i2c-ralink.c
  15
  16 diff --git a/Documentation/devicetree/bindings/i2c/i2c-ralink.txt b/Documentation/devicetree/bindings/i2c/i2c-ralink.txt
  17 new file mode 100644
  18 index 0000000..8fa8ac3
  19 --- /dev/null
  20 +++ b/Documentation/devicetree/bindings/i2c/i2c-ralink.txt
  21 @@ -0,0 +1,27 @@
  22 +I2C for Ralink platforms
  23 +
  24 +Required properties :
  25 +- compatible : Must be "link,rt3052-i2c"
  26 +- reg: physical base address of the controller and length of memory mapped
  27 +     region.
  28 +- #address-cells = <1>;
  29 +- #size-cells = <0>;
  30 +
  31 +Optional properties:
  32 +- Child nodes conforming to i2c bus binding
  33 +
  34 +Example :
  35 +
  36 +palmbus@10000000 {
  37 +       i2c@900 {
  38 +               compatible = "link,rt3052-i2c";
  39 +               reg = <0x900 0x100>;
  40 +               #address-cells = <1>;
  41 +               #size-cells = <0>;
  42 +
  43 +               hwmon@4b {
  44 +                       compatible = "national,lm92";
  45 +                       reg = <0x4b>;
  46 +               };
  47 +       };
  48 +};
  49 diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
  50 index bdca511..19b1105 100644
  51 --- a/drivers/i2c/busses/Kconfig
  52 +++ b/drivers/i2c/busses/Kconfig
  53 @@ -604,6 +604,10 @@ config I2C_PXA_SLAVE
  54           is necessary for systems where the PXA may be a target on the
  55           I2C bus.
  56
  57 +config I2C_RALINK
  58 +       tristate "Ralink I2C Controller"
  59 +       select OF_I2C
  60 +
  61  config HAVE_S3C2410_I2C
  62         bool
  63         help
  64 diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
  65 index 6181f3f..4cf4a88 100644
  66 --- a/drivers/i2c/busses/Makefile
  67 +++ b/drivers/i2c/busses/Makefile
  68 @@ -60,6 +60,7 @@ obj-$(CONFIG_I2C_PNX)         += i2c-pnx.o
  69  obj-$(CONFIG_I2C_PUV3)         += i2c-puv3.o
  70  obj-$(CONFIG_I2C_PXA)          += i2c-pxa.o
  71  obj-$(CONFIG_I2C_PXA_PCI)      += i2c-pxa-pci.o
  72 +obj-$(CONFIG_I2C_RALINK)       += i2c-ralink.o
  73  obj-$(CONFIG_I2C_S3C2410)      += i2c-s3c2410.o
  74  obj-$(CONFIG_I2C_S6000)                += i2c-s6000.o
  75  obj-$(CONFIG_I2C_SH7760)       += i2c-sh7760.o
  76 diff --git a/drivers/i2c/busses/i2c-ralink.c b/drivers/i2c/busses/i2c-ralink.c
  77 new file mode 100644
  78 index 0000000..b5abf0f
  79 --- /dev/null
  80 +++ b/drivers/i2c/busses/i2c-ralink.c
  81 @@ -0,0 +1,274 @@
  82 +/*
  83 + * drivers/i2c/busses/i2c-ralink.c
  84 + *
  85 + * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
  86 + *
  87 + * This software is licensed under the terms of the GNU General Public
  88 + * License version 2, as published by the Free Software Foundation, and
  89 + * may be copied, distributed, and modified under those terms.
  90 + *
  91 + * This program is distributed in the hope that it will be useful,
  92 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  93 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  94 + * GNU General Public License for more details.
  95 + *
  96 + */
  97 +
  98 +#include <linux/interrupt.h>
  99 +#include <linux/kernel.h>
 100 +#include <linux/module.h>
 101 +#include <linux/reset.h>
 102 +#include <linux/delay.h>
 103 +#include <linux/slab.h>
 104 +#include <linux/init.h>
 105 +#include <linux/errno.h>
 106 +#include <linux/platform_device.h>
 107 +#include <linux/i2c.h>
 108 +#include <linux/io.h>
 109 +#include <linux/of_i2c.h>
 110 +#include <linux/err.h>
 111 +
 112 +#include <asm/mach-ralink/ralink_regs.h>
 113 +
 114 +#define REG_CONFIG_REG         0x00
 115 +#define REG_CLKDIV_REG         0x04
 116 +#define REG_DEVADDR_REG                0x08
 117 +#define REG_ADDR_REG           0x0C
 118 +#define REG_DATAOUT_REG                0x10
 119 +#define REG_DATAIN_REG         0x14
 120 +#define REG_STATUS_REG         0x18
 121 +#define REG_STARTXFR_REG       0x1C
 122 +#define REG_BYTECNT_REG                0x20
 123 +
 124 +#define I2C_STARTERR           BIT(4)
 125 +#define I2C_ACKERR             BIT(3)
 126 +#define I2C_DATARDY            BIT(2)
 127 +#define I2C_SDOEMPTY           BIT(1)
 128 +#define I2C_BUSY               BIT(0)
 129 +
 130 +#define I2C_DEVADLEN_7         (6 << 2)
 131 +#define I2C_ADDRDIS            BIT(1)
 132 +
 133 +#define I2C_RETRY              0x400
 134 +
 135 +#define CLKDIV_VALUE           600
 136 +
 137 +#define READ_CMD               0x01
 138 +#define WRITE_CMD              0x00
 139 +#define READ_BLOCK              64
 140 +
 141 +static void __iomem *membase;
 142 +static struct i2c_adapter *adapter;
 143 +
 144 +static void rt_i2c_w32(u32 val, unsigned reg)
 145 +{
 146 +       iowrite32(val, membase + reg);
 147 +}
 148 +
 149 +static u32 rt_i2c_r32(unsigned reg)
 150 +{
 151 +       return ioread32(membase + reg);
 152 +}
 153 +
 154 +static inline int rt_i2c_wait_rx_done(void)
 155 +{
 156 +       int retries = I2C_RETRY;
 157 +
 158 +       do {
 159 +               if (!retries--)
 160 +                       break;
 161 +       } while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
 162 +
 163 +       return (retries < 0);
 164 +}
 165 +
 166 +static inline int rt_i2c_wait_idle(void)
 167 +{
 168 +       int retries = I2C_RETRY;
 169 +
 170 +       do {
 171 +               if (!retries--)
 172 +                       break;
 173 +       } while(rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
 174 +
 175 +       return (retries < 0);
 176 +}
 177 +
 178 +static inline int rt_i2c_wait_tx_done(void)
 179 +{
 180 +       int retries = I2C_RETRY;
 181 +
 182 +       do {
 183 +               if (!retries--)
 184 +                       break;
 185 +       } while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
 186 +
 187 +       return (retries < 0);
 188 +}
 189 +
 190 +static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
 191 +{
 192 +       int i = 0, j = 0, pos = 0;
 193 +       int nblock = msg->len / READ_BLOCK;
 194 +        int rem = msg->len % READ_BLOCK;
 195 +
 196 +       if (msg->flags & I2C_M_TEN) {
 197 +               printk("10 bits addr not supported\n");
 198 +               return -EINVAL;
 199 +       }
 200 +
 201 +       if (msg->flags & I2C_M_RD) {
 202 +               for (i = 0; i < nblock; i++) {
 203 +                       rt_i2c_wait_idle();
 204 +                       rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
 205 +                       rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
 206 +                       for (j = 0; j < READ_BLOCK; j++) {
 207 +                               if (rt_i2c_wait_rx_done())
 208 +                                       return -1;
 209 +                               msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
 210 +                       }
 211 +               }
 212 +
 213 +               rt_i2c_wait_idle();
 214 +               rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
 215 +               rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
 216 +               for (i = 0; i < rem; i++) {
 217 +                       if (rt_i2c_wait_rx_done())
 218 +                               return -1;
 219 +                       msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
 220 +               }
 221 +       } else {
 222 +               rt_i2c_wait_idle();
 223 +               rt_i2c_w32(msg->len - 1, REG_BYTECNT_REG);
 224 +               rt_i2c_w32(msg->buf[0], REG_DATAOUT_REG);
 225 +               rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
 226 +               for (i = 1; i < msg->len; i++) {
 227 +                       rt_i2c_w32(msg->buf[i], REG_DATAOUT_REG);
 228 +                       if (rt_i2c_wait_tx_done())
 229 +                               return -1;
 230 +               }
 231 +       }
 232 +
 233 +       return msg->len;
 234 +}
 235 +
 236 +static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
 237 +{
 238 +       int i = 0;
 239 +       int ret = 0;
 240 +
 241 +       if (rt_i2c_wait_idle()) {
 242 +               printk("i2c transfer failed\n");
 243 +               return 0;
 244 +       }
 245 +
 246 +       device_reset(a->dev.parent);
 247 +
 248 +       rt_i2c_w32(m->addr, REG_DEVADDR_REG);
 249 +       rt_i2c_w32(I2C_DEVADLEN_7 | I2C_ADDRDIS, REG_CONFIG_REG);
 250 +       rt_i2c_w32(CLKDIV_VALUE, REG_CLKDIV_REG);
 251 +
 252 +       for (i = 0; i < n && !ret; i++)
 253 +               ret = rt_i2c_handle_msg(a, &m[i]);
 254 +
 255 +       if (ret) {
 256 +               printk("i2c transfer failed\n");
 257 +               return 0;
 258 +       }
 259 +
 260 +       return n;
 261 +}
 262 +
 263 +static u32 rt_i2c_func(struct i2c_adapter *a)
 264 +{
 265 +       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 266 +}
 267 +
 268 +static const struct i2c_algorithm rt_i2c_algo = {
 269 +       .master_xfer    = rt_i2c_master_xfer,
 270 +       .functionality  = rt_i2c_func,
 271 +};
 272 +
 273 +static int rt_i2c_probe(struct platform_device *pdev)
 274 +{
 275 +       struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 276 +       int ret;
 277 +
 278 +       if (!res) {
 279 +               dev_err(&pdev->dev, "no memory resource found\n");
 280 +               return -ENODEV;
 281 +       }
 282 +
 283 +       adapter = devm_kzalloc(&pdev->dev, sizeof(struct i2c_adapter), GFP_KERNEL);
 284 +       if (!adapter) {
 285 +               dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
 286 +               return -ENOMEM;
 287 +       }
 288 +
 289 +       membase = devm_request_and_ioremap(&pdev->dev, res);
 290 +       if (IS_ERR(membase))
 291 +               return PTR_ERR(membase);
 292 +
 293 +       strlcpy(adapter->name, dev_name(&pdev->dev), sizeof(adapter->name));
 294 +       adapter->owner = THIS_MODULE;
 295 +       adapter->nr = pdev->id;
 296 +       adapter->timeout = HZ;
 297 +       adapter->algo = &rt_i2c_algo;
 298 +       adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 299 +       adapter->dev.parent = &pdev->dev;
 300 +       adapter->dev.of_node = pdev->dev.of_node;
 301 +
 302 +       ret = i2c_add_numbered_adapter(adapter);
 303 +       if (ret)
 304 +               return ret;
 305 +
 306 +       of_i2c_register_devices(adapter);
 307 +
 308 +       platform_set_drvdata(pdev, adapter);
 309 +
 310 +       dev_info(&pdev->dev, "loaded\n");
 311 +
 312 +       return 0;
 313 +}
 314 +
 315 +static int rt_i2c_remove(struct platform_device *pdev)
 316 +{
 317 +       platform_set_drvdata(pdev, NULL);
 318 +
 319 +       return 0;
 320 +}
 321 +
 322 +static const struct of_device_id i2c_rt_dt_ids[] = {
 323 +       { .compatible = "ralink,rt2880-i2c", },
 324 +       { /* sentinel */ }
 325 +};
 326 +
 327 +MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
 328 +
 329 +static struct platform_driver rt_i2c_driver = {
 330 +       .probe          = rt_i2c_probe,
 331 +       .remove         = rt_i2c_remove,
 332 +       .driver         = {
 333 +               .owner  = THIS_MODULE,
 334 +               .name   = "i2c-ralink",
 335 +               .of_match_table = i2c_rt_dt_ids,
 336 +       },
 337 +};
 338 +
 339 +static int __init i2c_rt_init (void)
 340 +{
 341 +       return platform_driver_register(&rt_i2c_driver);
 342 +}
 343 +subsys_initcall(i2c_rt_init);
 344 +
 345 +static void __exit i2c_rt_exit (void)
 346 +{
 347 +       platform_driver_unregister(&rt_i2c_driver);
 348 +}
 349 +
 350 +module_exit (i2c_rt_exit);
 351 +
 352 +MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
 353 +MODULE_DESCRIPTION("Ralink I2c host driver");
 354 +MODULE_LICENSE("GPL");
 355 +MODULE_ALIAS("platform:Ralink-I2C");
 356 --
 357 1.7.10.4
 358