target/linux/ramips/patches-4.3/0044-i2c-MIPS-adds-ralink-I2C-driver.patch

   1 From 723b8beaabf3c3c4b1ce69480141f1e926f3f3b2 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 27 Jul 2014 09:52:56 +0100
   4 Subject: [PATCH 44/53] 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                    |  327 ++++++++++++++++++++
  12  4 files changed, 359 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 08b8617..53d565b 100644
  51 --- a/drivers/i2c/busses/Kconfig
  52 +++ b/drivers/i2c/busses/Kconfig
  53 @@ -803,6 +803,10 @@ config I2C_RK3X
  54           This driver can also be built as a module. If so, the module will
  55           be called i2c-rk3x.
  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 6df3b30..2edd32c 100644
  66 --- a/drivers/i2c/busses/Makefile
  67 +++ b/drivers/i2c/busses/Makefile
  68 @@ -75,6 +75,7 @@ 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_QUP)          += i2c-qup.o
  74  obj-$(CONFIG_I2C_RIIC)         += i2c-riic.o
  75  obj-$(CONFIG_I2C_RK3X)         += i2c-rk3x.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..debfb18
  79 --- /dev/null
  80 +++ b/drivers/i2c/busses/i2c-ralink.c
  81 @@ -0,0 +1,327 @@
  82 +/*
  83 + * drivers/i2c/busses/i2c-ralink.c
  84 + *
  85 + * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
  86 + *
  87 + * Improve driver for i2cdetect from i2c-tools to detect i2c devices on the bus.
  88 + * (C) 2014 Sittisak <sittisaks@hotmail.com>
  89 + *
  90 + * This software is licensed under the terms of the GNU General Public
  91 + * License version 2, as published by the Free Software Foundation, and
  92 + * may be copied, distributed, and modified under those terms.
  93 + *
  94 + * This program is distributed in the hope that it will be useful,
  95 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  96 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  97 + * GNU General Public License for more details.
  98 + *
  99 + */
 100 +
 101 +#include <linux/interrupt.h>
 102 +#include <linux/kernel.h>
 103 +#include <linux/module.h>
 104 +#include <linux/reset.h>
 105 +#include <linux/delay.h>
 106 +#include <linux/slab.h>
 107 +#include <linux/init.h>
 108 +#include <linux/errno.h>
 109 +#include <linux/platform_device.h>
 110 +#include <linux/of_platform.h>
 111 +#include <linux/i2c.h>
 112 +#include <linux/io.h>
 113 +#include <linux/err.h>
 114 +
 115 +#include <asm/mach-ralink/ralink_regs.h>
 116 +
 117 +#define REG_CONFIG_REG         0x00
 118 +#define REG_CLKDIV_REG         0x04
 119 +#define REG_DEVADDR_REG                0x08
 120 +#define REG_ADDR_REG           0x0C
 121 +#define REG_DATAOUT_REG                0x10
 122 +#define REG_DATAIN_REG         0x14
 123 +#define REG_STATUS_REG         0x18
 124 +#define REG_STARTXFR_REG       0x1C
 125 +#define REG_BYTECNT_REG                0x20
 126 +#define REG_SM0CFG2            0x28
 127 +#define REG_SM0CTL0            0x40
 128 +
 129 +#define I2C_STARTERR           BIT(4)
 130 +#define I2C_ACKERR             BIT(3)
 131 +#define I2C_DATARDY            BIT(2)
 132 +#define I2C_SDOEMPTY           BIT(1)
 133 +#define I2C_BUSY               BIT(0)
 134 +
 135 +#define I2C_DEVADLEN_7         (6 << 2)
 136 +#define I2C_ADDRDIS            BIT(1)
 137 +
 138 +#define CLKDIV_VALUE           200 // clock rate is 40M, 40M / (200*2) = 100k (standard i2c bus rate).
 139 +//#define CLKDIV_VALUE         50 // clock rate is 40M, 40M / (50*2) = 400k (fast i2c bus rate).
 140 +
 141 +#define READ_CMD               0x01
 142 +#define WRITE_CMD              0x00
 143 +#define READ_BLOCK              64
 144 +
 145 +#define SM0CTL0_OD             BIT(31)
 146 +#define SM0CTL0_VTRIG          BIT(28)
 147 +#define SM0CTL0_OUTHI          BIT(6)
 148 +#define SM0CTL0_STRETCH                BIT(1)
 149 +#define SM0CTL0_DEFAULT                (SM0CTL0_OD | SM0CTL0_VTRIG | SM0CTL0_OUTHI | SM0CTL0_STRETCH)
 150 +
 151 +/* timeout waiting for I2C devices to respond (clock streching) */
 152 +#define RT_I2C_TIMEOUT (msecs_to_jiffies(1000))
 153 +
 154 +enum {
 155 +       I2C_TYPE_RALINK,
 156 +       I2C_TYPE_MEDIATEK,
 157 +};
 158 +
 159 +static void __iomem *membase;
 160 +static struct i2c_adapter *adapter;
 161 +static int hw_type;
 162 +
 163 +static void rt_i2c_w32(u32 val, unsigned reg)
 164 +{
 165 +       iowrite32(val, membase + reg);
 166 +}
 167 +
 168 +static u32 rt_i2c_r32(unsigned reg)
 169 +{
 170 +       return ioread32(membase + reg);
 171 +}
 172 +
 173 +static inline int rt_i2c_get_ack(void)
 174 +{
 175 +        return (rt_i2c_r32(REG_STATUS_REG) & I2C_ACKERR) ? -EIO : 0;
 176 +}
 177 +
 178 +static inline int rt_i2c_wait_rx_done(void)
 179 +{
 180 +       unsigned long timeout;
 181 +
 182 +       timeout = jiffies + RT_I2C_TIMEOUT;
 183 +
 184 +       do {
 185 +               if (time_after(jiffies, timeout))
 186 +                       return (-ETIMEDOUT);
 187 +
 188 +       } while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
 189 +
 190 +       return 0;
 191 +}
 192 +
 193 +static inline int rt_i2c_wait_idle(void)
 194 +{
 195 +       unsigned long timeout;
 196 +
 197 +       timeout = jiffies + RT_I2C_TIMEOUT;
 198 +
 199 +       do {
 200 +               if (time_after(jiffies, timeout)) {
 201 +                       printk("i2c-read line busy\n");
 202 +                       return 1;
 203 +               }
 204 +       } while (rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
 205 +
 206 +       return 0;
 207 +}
 208 +
 209 +static inline int rt_i2c_wait_tx_done(void)
 210 +{
 211 +       unsigned long timeout;
 212 +
 213 +       timeout = jiffies + RT_I2C_TIMEOUT;
 214 +
 215 +       do {
 216 +               if (time_after(jiffies, timeout))
 217 +                       return (-ETIMEDOUT);
 218 +
 219 +       } while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
 220 +
 221 +       return 0;
 222 +}
 223 +
 224 +static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
 225 +{
 226 +       int i = 0, j = 0, pos = 0;
 227 +       int nblock = msg->len / READ_BLOCK;
 228 +        int rem = msg->len % READ_BLOCK;
 229 +       int ret = 0;
 230 +
 231 +       if (msg->flags & I2C_M_TEN) {
 232 +               printk("10 bits addr not supported\n");
 233 +               return -EINVAL;
 234 +       }
 235 +
 236 +       if (msg->flags & I2C_M_RD) {
 237 +               for (i = 0; i < nblock; i++) {
 238 +                       if (rt_i2c_wait_idle())
 239 +                               return -ETIMEDOUT;
 240 +                       rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
 241 +                       rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
 242 +                       for (j = 0; j < READ_BLOCK; j++) {
 243 +                               if (rt_i2c_wait_rx_done() < 0)
 244 +                                       ret = rt_i2c_wait_rx_done();
 245 +                                if (rt_i2c_get_ack() < 0)
 246 +                                       ret = rt_i2c_get_ack();
 247 +                               msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
 248 +                       }
 249 +               }
 250 +
 251 +               if (rt_i2c_wait_idle())
 252 +                       return -ETIMEDOUT;
 253 +               if (rem) {
 254 +                       rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
 255 +                       rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
 256 +               }
 257 +               for (i = 0; i < rem; i++) {
 258 +                       if (rt_i2c_wait_rx_done() < 0)
 259 +                               ret = rt_i2c_wait_rx_done();
 260 +                        if (rt_i2c_get_ack() < 0)
 261 +                               ret = rt_i2c_get_ack();
 262 +
 263 +                       msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
 264 +               }
 265 +       } else {
 266 +               if (rt_i2c_wait_idle())
 267 +                       return -ETIMEDOUT;
 268 +               rt_i2c_w32(msg->len - 1, REG_BYTECNT_REG);
 269 +               for (i = 0; i < msg->len; i++) {
 270 +                       rt_i2c_w32(msg->buf[i], REG_DATAOUT_REG);
 271 +                       rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
 272 +
 273 +                       if (rt_i2c_wait_tx_done() < 0)
 274 +                               ret = rt_i2c_wait_tx_done();
 275 +                        if (rt_i2c_get_ack() < 0)
 276 +                               ret = rt_i2c_get_ack();
 277 +               }
 278 +       }
 279 +
 280 +       return ret;
 281 +}
 282 +
 283 +static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
 284 +{
 285 +       int i = 0;
 286 +       int ret = 0;
 287 +
 288 +       if (rt_i2c_wait_idle())
 289 +               return -ETIMEDOUT;
 290 +
 291 +       device_reset(a->dev.parent);
 292 +
 293 +       rt_i2c_w32(m->addr, REG_DEVADDR_REG);
 294 +       rt_i2c_w32(I2C_DEVADLEN_7 | I2C_ADDRDIS, REG_CONFIG_REG);
 295 +       if (hw_type == I2C_TYPE_RALINK) {
 296 +               rt_i2c_w32(CLKDIV_VALUE, REG_CLKDIV_REG);
 297 +       } else {
 298 +               rt_i2c_w32((CLKDIV_VALUE << 16) | SM0CTL0_DEFAULT, REG_SM0CTL0);
 299 +               rt_i2c_w32(1, REG_SM0CFG2);
 300 +       }
 301 +
 302 +       for (i = 0; i < n && !ret; i++) {
 303 +               ret = rt_i2c_handle_msg(a, &m[i]);
 304 +
 305 +               if (ret < 0) {
 306 +                       return ret;
 307 +               }
 308 +       }
 309 +
 310 +       return n;
 311 +}
 312 +
 313 +static u32 rt_i2c_func(struct i2c_adapter *a)
 314 +{
 315 +       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 316 +}
 317 +
 318 +static const struct i2c_algorithm rt_i2c_algo = {
 319 +       .master_xfer    = rt_i2c_master_xfer,
 320 +       .functionality  = rt_i2c_func,
 321 +};
 322 +
 323 +static const struct of_device_id i2c_rt_dt_ids[] = {
 324 +       { .compatible = "ralink,rt2880-i2c", .data = (void *) I2C_TYPE_RALINK },
 325 +       { .compatible = "mediatek,mt7628-i2c", .data = (void *) I2C_TYPE_MEDIATEK },
 326 +       { /* sentinel */ }
 327 +};
 328 +
 329 +MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
 330 +
 331 +static int rt_i2c_probe(struct platform_device *pdev)
 332 +{
 333 +       struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 334 +       const struct of_device_id *match;
 335 +       int ret;
 336 +
 337 +       match = of_match_device(i2c_rt_dt_ids, &pdev->dev);
 338 +       hw_type = (int) match->data;
 339 +
 340 +       if (!res) {
 341 +               dev_err(&pdev->dev, "no memory resource found\n");
 342 +               return -ENODEV;
 343 +       }
 344 +
 345 +       adapter = devm_kzalloc(&pdev->dev, sizeof(struct i2c_adapter), GFP_KERNEL);
 346 +       if (!adapter) {
 347 +               dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
 348 +               return -ENOMEM;
 349 +       }
 350 +
 351 +       membase = devm_ioremap_resource(&pdev->dev, res);
 352 +       if (IS_ERR(membase))
 353 +               return PTR_ERR(membase);
 354 +
 355 +       strlcpy(adapter->name, dev_name(&pdev->dev), sizeof(adapter->name));
 356 +       adapter->owner = THIS_MODULE;
 357 +       adapter->nr = pdev->id;
 358 +       adapter->timeout = HZ;
 359 +       adapter->algo = &rt_i2c_algo;
 360 +       adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 361 +       adapter->dev.parent = &pdev->dev;
 362 +       adapter->dev.of_node = pdev->dev.of_node;
 363 +
 364 +       ret = i2c_add_numbered_adapter(adapter);
 365 +       if (ret)
 366 +               return ret;
 367 +
 368 +       platform_set_drvdata(pdev, adapter);
 369 +
 370 +       dev_info(&pdev->dev, "loaded\n");
 371 +
 372 +       return 0;
 373 +}
 374 +
 375 +static int rt_i2c_remove(struct platform_device *pdev)
 376 +{
 377 +       platform_set_drvdata(pdev, NULL);
 378 +
 379 +       return 0;
 380 +}
 381 +
 382 +static struct platform_driver rt_i2c_driver = {
 383 +       .probe          = rt_i2c_probe,
 384 +       .remove         = rt_i2c_remove,
 385 +       .driver         = {
 386 +               .owner  = THIS_MODULE,
 387 +               .name   = "i2c-ralink",
 388 +               .of_match_table = i2c_rt_dt_ids,
 389 +       },
 390 +};
 391 +
 392 +static int __init i2c_rt_init (void)
 393 +{
 394 +       return platform_driver_register(&rt_i2c_driver);
 395 +}
 396 +subsys_initcall(i2c_rt_init);
 397 +
 398 +static void __exit i2c_rt_exit (void)
 399 +{
 400 +       platform_driver_unregister(&rt_i2c_driver);
 401 +}
 402 +
 403 +module_exit (i2c_rt_exit);
 404 +
 405 +MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
 406 +MODULE_DESCRIPTION("Ralink I2c host driver");
 407 +MODULE_LICENSE("GPL");
 408 +MODULE_ALIAS("platform:Ralink-I2C");
 409 --
 410 1.7.10.4
 411