target/linux/ramips/patches-4.4/0045-i2c-add-mt7621-driver.patch

   1 From d5c54ff3d1db0a4348fa04d8e78f3bf6063e3afc Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Mon, 7 Dec 2015 17:21:27 +0100
   4 Subject: [PATCH 45/53] i2c: add mt7621 driver
   5
   6 Signed-off-by: John Crispin <blogic@openwrt.org>
   7 ---
   8  drivers/i2c/busses/Kconfig      |    4 +
   9  drivers/i2c/busses/Makefile     |    1 +
  10  drivers/i2c/busses/i2c-mt7621.c |  303 +++++++++++++++++++++++++++++++++++++++
  11  3 files changed, 308 insertions(+)
  12  create mode 100644 drivers/i2c/busses/i2c-mt7621.c
  13
  14 --- a/drivers/i2c/busses/Kconfig
  15 +++ b/drivers/i2c/busses/Kconfig
  16 @@ -810,6 +810,10 @@ config I2C_RALINK
  17         tristate "Ralink I2C Controller"
  18         select OF_I2C
  19
  20 +config I2C_MT7621
  21 +       tristate "MT7621 I2C Controller"
  22 +       select OF_I2C
  23 +
  24  config HAVE_S3C2410_I2C
  25         bool
  26         help
  27 --- a/drivers/i2c/busses/Makefile
  28 +++ b/drivers/i2c/busses/Makefile
  29 @@ -76,6 +76,7 @@ obj-$(CONFIG_I2C_PUV3)                += i2c-puv3.o
  30  obj-$(CONFIG_I2C_PXA)          += i2c-pxa.o
  31  obj-$(CONFIG_I2C_PXA_PCI)      += i2c-pxa-pci.o
  32  obj-$(CONFIG_I2C_RALINK)       += i2c-ralink.o
  33 +obj-$(CONFIG_I2C_MT7621)       += i2c-mt7621.o
  34  obj-$(CONFIG_I2C_QUP)          += i2c-qup.o
  35  obj-$(CONFIG_I2C_RIIC)         += i2c-riic.o
  36  obj-$(CONFIG_I2C_RK3X)         += i2c-rk3x.o
  37 --- /dev/null
  38 +++ b/drivers/i2c/busses/i2c-mt7621.c
  39 @@ -0,0 +1,303 @@
  40 +/*
  41 + * drivers/i2c/busses/i2c-mt7621.c
  42 + *
  43 + * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
  44 + *
  45 + * Improve driver for i2cdetect from i2c-tools to detect i2c devices on the bus.
  46 + * (C) 2014 Sittisak <sittisaks@hotmail.com>
  47 + *
  48 + * This software is licensed under the terms of the GNU General Public
  49 + * License version 2, as published by the Free Software Foundation, and
  50 + * may be copied, distributed, and modified under those terms.
  51 + *
  52 + * This program is distributed in the hope that it will be useful,
  53 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  54 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  55 + * GNU General Public License for more details.
  56 + *
  57 + */
  58 +
  59 +#include <linux/interrupt.h>
  60 +#include <linux/kernel.h>
  61 +#include <linux/module.h>
  62 +#include <linux/reset.h>
  63 +#include <linux/delay.h>
  64 +#include <linux/slab.h>
  65 +#include <linux/init.h>
  66 +#include <linux/errno.h>
  67 +#include <linux/platform_device.h>
  68 +#include <linux/i2c.h>
  69 +#include <linux/io.h>
  70 +#include <linux/err.h>
  71 +
  72 +#include <asm/mach-ralink/ralink_regs.h>
  73 +
  74 +#define REG_CONFIG_REG                       0x00
  75 +#define REG_CLKDIV_REG                       0x04
  76 +#define REG_DEVADDR_REG                      0x08
  77 +#define REG_ADDR_REG                         0x0C
  78 +#define REG_DATAOUT_REG                      0x10
  79 +#define REG_DATAIN_REG                       0x14
  80 +#define REG_STATUS_REG                       0x18
  81 +#define REG_STARTXFR_REG                     0x1C
  82 +#define REG_BYTECNT_REG                      0x20
  83 +#define REG_SM0_IS_AUTOMODE                  0x28
  84 +#define REG_SM0CTL0                          0x40
  85 +
  86 +
  87 +#define I2C_STARTERR                         0x10
  88 +#define I2C_ACKERR                           0x08
  89 +#define I2C_DATARDY                          0x04
  90 +#define I2C_SDOEMPTY                         0x02
  91 +#define I2C_BUSY                             0x01
  92 +
  93 +/* I2C_CFG register bit field */
  94 +#define I2C_CFG_ADDRLEN_8                    (7<<5)    /* 8 bits */
  95 +#define I2C_CFG_DEVADLEN_7                   (6<<2)
  96 +#define I2C_CFG_ADDRDIS                      BIT(1)
  97 +#define I2C_CFG_DEVADDIS                     BIT(0)
  98 +
  99 +#define I2C_CFG_DEFAULT        (I2C_CFG_ADDRLEN_8 | \
 100 +               I2C_CFG_DEVADLEN_7 | \
 101 +               I2C_CFG_ADDRDIS)
 102 +
 103 +#define I2C_RETRY                            0x1000
 104 +
 105 +#define CLKDIV_VALUE                         333
 106 +#define i2c_busy_loop                        (CLKDIV_VALUE*30)
 107 +
 108 +#define READ_CMD                             0x01
 109 +#define WRITE_CMD                            0x00
 110 +#define READ_BLOCK                           16
 111 +
 112 +#define SM0_ODRAIN                           BIT(31)
 113 +#define SM0_VSYNC_MODE                       BIT(28)
 114 +#define SM0_CLK_DIV                          (CLKDIV_VALUE << 16)
 115 +#define SM0_WAIT_LEVEL                       BIT(6)
 116 +#define SM0_EN                               BIT(1)
 117 +
 118 +#define SM0_CFG_DEFUALT (SM0_ODRAIN | SM0_VSYNC_MODE | \
 119 +                        SM0_CLK_DIV | SM0_WAIT_LEVEL | \
 120 +                        SM0_EN)
 121 +/***********************************************************/
 122 +
 123 +static void __iomem *membase;
 124 +static struct i2c_adapter *adapter;
 125 +
 126 +static void rt_i2c_w32(u32 val, unsigned reg)
 127 +{
 128 +       iowrite32(val, membase + reg);
 129 +}
 130 +
 131 +static u32 rt_i2c_r32(unsigned reg)
 132 +{
 133 +       return ioread32(membase + reg);
 134 +}
 135 +
 136 +static void mt7621_i2c_reset(struct i2c_adapter *a)
 137 +{
 138 +       device_reset(a->dev.parent);
 139 +}
 140 +static void mt7621_i2c_enable(struct i2c_msg *msg)
 141 +{
 142 +       rt_i2c_w32(msg->addr,REG_DEVADDR_REG);
 143 +       rt_i2c_w32(0,REG_ADDR_REG);
 144 +}
 145 +
 146 +static void i2c_master_init(struct i2c_adapter *a)
 147 +{
 148 +       mt7621_i2c_reset(a);
 149 +       rt_i2c_w32(I2C_CFG_DEFAULT,REG_CONFIG_REG);
 150 +       rt_i2c_w32(SM0_CFG_DEFUALT,REG_SM0CTL0);
 151 +       rt_i2c_w32(1,REG_SM0_IS_AUTOMODE);//auto mode
 152 +}
 153 +
 154 +
 155 +static inline int rt_i2c_wait_rx_done(void)
 156 +{
 157 +       int i=0;
 158 +       while((!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY)) && (i<i2c_busy_loop))
 159 +               i++;
 160 +       if(i>=i2c_busy_loop){
 161 +               pr_err("err,wait for idle timeout");
 162 +               return -ETIMEDOUT;
 163 +       }
 164 +       return 0;
 165 +}
 166 +
 167 +static inline int rt_i2c_wait_idle(void)
 168 +{
 169 +       int i=0;
 170 +       while((rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY) && (i<i2c_busy_loop))
 171 +               i++;
 172 +       if(i>=i2c_busy_loop){
 173 +               pr_err("err,wait for idle timeout");
 174 +               return -ETIMEDOUT;
 175 +       }
 176 +       return 0;
 177 +}
 178 +
 179 +static inline int rt_i2c_wait_tx_done(void)
 180 +{
 181 +       int i=0;
 182 +       while((!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY)) && (i<i2c_busy_loop))
 183 +               i++;
 184 +       if(i>=i2c_busy_loop){
 185 +               pr_err("err,wait for idle timeout");
 186 +               return -ETIMEDOUT;
 187 +       }
 188 +       return 0;
 189 +}
 190 +
 191 +static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
 192 +{
 193 +       int i = 0, j = 0, pos = 0;
 194 +       int nblock = msg->len / READ_BLOCK;
 195 +       int rem = msg->len % READ_BLOCK;
 196 +
 197 +       if (msg->flags & I2C_M_TEN) {
 198 +               printk("10 bits addr not supported\n");
 199 +               return -EINVAL;
 200 +       }
 201 +
 202 +       if (msg->flags & I2C_M_RD) {
 203 +               for (i = 0; i < nblock; i++) {
 204 +                       if (rt_i2c_wait_idle())
 205 +                               goto err_timeout;
 206 +                       rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
 207 +                       rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
 208 +                       for (j = 0; j < READ_BLOCK; j++) {
 209 +                               if (rt_i2c_wait_rx_done())
 210 +                                       goto err_timeout;
 211 +                               msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
 212 +                       }
 213 +               }
 214 +
 215 +               if (rt_i2c_wait_idle())
 216 +                   goto err_timeout;
 217 +               rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
 218 +               rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
 219 +
 220 +               for (i = 0; i < rem; i++) {
 221 +                       if (rt_i2c_wait_rx_done())
 222 +                               goto err_timeout;
 223 +                       msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
 224 +               }
 225 +       } else {
 226 +               if (rt_i2c_wait_idle())
 227 +                       goto err_timeout;
 228 +               rt_i2c_w32(msg->len - 1, REG_BYTECNT_REG);
 229 +               for (i = 0; i < msg->len; i++) {
 230 +                       rt_i2c_w32(msg->buf[i], REG_DATAOUT_REG);
 231 +                       if(i == 0)
 232 +                               rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
 233 +
 234 +                       if (rt_i2c_wait_tx_done())
 235 +                               goto err_timeout;
 236 +               }
 237 +       }
 238 +
 239 +       return 0;
 240 +err_timeout:
 241 +       return -ETIMEDOUT;
 242 +}
 243 +
 244 +static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
 245 +{
 246 +       int i = 0;
 247 +       int ret = 0;
 248 +       i2c_master_init(a);
 249 +       mt7621_i2c_enable(m);
 250 +
 251 +       for (i = 0; i != n && ret==0; i++) {
 252 +               ret = rt_i2c_handle_msg(a, &m[i]);
 253 +               if (ret)
 254 +                       return ret;
 255 +       }
 256 +       return i;
 257 +}
 258 +
 259 +static u32 rt_i2c_func(struct i2c_adapter *a)
 260 +{
 261 +       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 262 +}
 263 +
 264 +static const struct i2c_algorithm rt_i2c_algo = {
 265 +       .master_xfer    = rt_i2c_master_xfer,
 266 +       .functionality  = rt_i2c_func,
 267 +};
 268 +
 269 +static int rt_i2c_probe(struct platform_device *pdev)
 270 +{
 271 +       struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 272 +       int ret;
 273 +
 274 +       adapter = devm_kzalloc(&pdev->dev,sizeof(struct i2c_adapter), GFP_KERNEL);
 275 +       if (!adapter) {
 276 +               dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
 277 +               return -ENOMEM;
 278 +       }
 279 +       membase = devm_ioremap_resource(&pdev->dev, res);
 280 +       if (IS_ERR(membase))
 281 +               return PTR_ERR(membase);
 282 +
 283 +       strlcpy(adapter->name, dev_name(&pdev->dev), sizeof(adapter->name));
 284 +
 285 +       adapter->owner = THIS_MODULE;
 286 +       adapter->nr = pdev->id;
 287 +       adapter->timeout = HZ;
 288 +       adapter->algo = &rt_i2c_algo;
 289 +       adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 290 +       adapter->dev.parent = &pdev->dev;
 291 +       adapter->dev.of_node = pdev->dev.of_node;
 292 +
 293 +       platform_set_drvdata(pdev, adapter);
 294 +
 295 +       ret = i2c_add_numbered_adapter(adapter);
 296 +       if (ret)
 297 +               return ret;
 298 +
 299 +       dev_info(&pdev->dev,"loaded");
 300 +
 301 +       return 0;
 302 +}
 303 +
 304 +static int rt_i2c_remove(struct platform_device *pdev)
 305 +{
 306 +       platform_set_drvdata(pdev, NULL);
 307 +       return 0;
 308 +}
 309 +
 310 +static const struct of_device_id i2c_rt_dt_ids[] = {
 311 +       { .compatible = "ralink,i2c-mt7621", },
 312 +       { /* sentinel */ }
 313 +};
 314 +
 315 +MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
 316 +
 317 +static struct platform_driver rt_i2c_driver = {
 318 +       .probe          = rt_i2c_probe,
 319 +       .remove         = rt_i2c_remove,
 320 +       .driver         = {
 321 +               .owner  = THIS_MODULE,
 322 +               .name   = "i2c-mt7621",
 323 +               .of_match_table = i2c_rt_dt_ids,
 324 +       },
 325 +};
 326 +
 327 +static int __init i2c_rt_init (void)
 328 +{
 329 +       return platform_driver_register(&rt_i2c_driver);
 330 +}
 331 +
 332 +static void __exit i2c_rt_exit (void)
 333 +{
 334 +       platform_driver_unregister(&rt_i2c_driver);
 335 +}
 336 +module_init (i2c_rt_init);
 337 +module_exit (i2c_rt_exit);
 338 +
 339 +MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
 340 +MODULE_DESCRIPTION("MT7621 I2c host driver");
 341 +MODULE_LICENSE("GPL");
 342 +MODULE_ALIAS("platform:MT7621-I2C");