Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 Broadcom Corporation |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License as |
| 6 | * published by the Free Software Foundation version 2. |
| 7 | * |
| 8 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any |
| 9 | * kind, whether express or implied; without even the implied warranty |
| 10 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/clk.h> |
| 15 | #include <linux/delay.h> |
| 16 | #include <linux/device.h> |
| 17 | #include <linux/i2c.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/io.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/platform_device.h> |
| 23 | #include <linux/sched.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include <linux/version.h> |
| 26 | |
| 27 | #define N_DATA_REGS 8 |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 28 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 29 | /* |
| 30 | * PER_I2C/BSC count register mask depends on 1 byte/4 byte data register |
| 31 | * size. Cable modem and DSL SoCs with Peripheral i2c cores use 1 byte per |
| 32 | * data register whereas STB SoCs use 4 byte per data register transfer, |
| 33 | * account for this difference in total count per transaction and mask to |
| 34 | * use. |
| 35 | */ |
| 36 | #define BSC_CNT_REG1_MASK(nb) (nb == 1 ? GENMASK(3, 0) : GENMASK(5, 0)) |
| 37 | #define BSC_CNT_REG1_SHIFT 0 |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 38 | |
| 39 | /* BSC CTL register field definitions */ |
| 40 | #define BSC_CTL_REG_DTF_MASK 0x00000003 |
| 41 | #define BSC_CTL_REG_SCL_SEL_MASK 0x00000030 |
| 42 | #define BSC_CTL_REG_SCL_SEL_SHIFT 4 |
| 43 | #define BSC_CTL_REG_INT_EN_MASK 0x00000040 |
| 44 | #define BSC_CTL_REG_INT_EN_SHIFT 6 |
| 45 | #define BSC_CTL_REG_DIV_CLK_MASK 0x00000080 |
| 46 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 47 | /* BSC_IIC_ENABLE r/w enable and interrupt field definitions */ |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 48 | #define BSC_IIC_EN_RESTART_MASK 0x00000040 |
| 49 | #define BSC_IIC_EN_NOSTART_MASK 0x00000020 |
| 50 | #define BSC_IIC_EN_NOSTOP_MASK 0x00000010 |
| 51 | #define BSC_IIC_EN_NOACK_MASK 0x00000004 |
| 52 | #define BSC_IIC_EN_INTRP_MASK 0x00000002 |
| 53 | #define BSC_IIC_EN_ENABLE_MASK 0x00000001 |
| 54 | |
| 55 | /* BSC_CTLHI control register field definitions */ |
| 56 | #define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK 0x00000080 |
| 57 | #define BSC_CTLHI_REG_DATAREG_SIZE_MASK 0x00000040 |
| 58 | #define BSC_CTLHI_REG_IGNORE_ACK_MASK 0x00000002 |
| 59 | #define BSC_CTLHI_REG_WAIT_DIS_MASK 0x00000001 |
| 60 | |
| 61 | #define I2C_TIMEOUT 100 /* msecs */ |
| 62 | |
| 63 | /* Condition mask used for non combined transfer */ |
| 64 | #define COND_RESTART BSC_IIC_EN_RESTART_MASK |
| 65 | #define COND_NOSTART BSC_IIC_EN_NOSTART_MASK |
| 66 | #define COND_NOSTOP BSC_IIC_EN_NOSTOP_MASK |
| 67 | #define COND_START_STOP (COND_RESTART | COND_NOSTART | COND_NOSTOP) |
| 68 | |
| 69 | /* BSC data transfer direction */ |
| 70 | #define DTF_WR_MASK 0x00000000 |
| 71 | #define DTF_RD_MASK 0x00000001 |
| 72 | /* BSC data transfer direction combined format */ |
| 73 | #define DTF_RD_WR_MASK 0x00000002 |
| 74 | #define DTF_WR_RD_MASK 0x00000003 |
| 75 | |
| 76 | #define INT_ENABLE true |
| 77 | #define INT_DISABLE false |
| 78 | |
| 79 | /* BSC block register map structure to cache fields to be written */ |
| 80 | struct bsc_regs { |
| 81 | u32 chip_address; /* slave address */ |
| 82 | u32 data_in[N_DATA_REGS]; /* tx data buffer*/ |
| 83 | u32 cnt_reg; /* rx/tx data length */ |
| 84 | u32 ctl_reg; /* control register */ |
| 85 | u32 iic_enable; /* xfer enable and status */ |
| 86 | u32 data_out[N_DATA_REGS]; /* rx data buffer */ |
| 87 | u32 ctlhi_reg; /* more control fields */ |
| 88 | u32 scl_param; /* reserved */ |
| 89 | }; |
| 90 | |
| 91 | struct bsc_clk_param { |
| 92 | u32 hz; |
| 93 | u32 scl_mask; |
| 94 | u32 div_mask; |
| 95 | }; |
| 96 | |
| 97 | enum bsc_xfer_cmd { |
| 98 | CMD_WR, |
| 99 | CMD_RD, |
| 100 | CMD_WR_NOACK, |
| 101 | CMD_RD_NOACK, |
| 102 | }; |
| 103 | |
| 104 | static char const *cmd_string[] = { |
| 105 | [CMD_WR] = "WR", |
| 106 | [CMD_RD] = "RD", |
| 107 | [CMD_WR_NOACK] = "WR NOACK", |
| 108 | [CMD_RD_NOACK] = "RD NOACK", |
| 109 | }; |
| 110 | |
| 111 | enum bus_speeds { |
| 112 | SPD_375K, |
| 113 | SPD_390K, |
| 114 | SPD_187K, |
| 115 | SPD_200K, |
| 116 | SPD_93K, |
| 117 | SPD_97K, |
| 118 | SPD_46K, |
| 119 | SPD_50K |
| 120 | }; |
| 121 | |
| 122 | static const struct bsc_clk_param bsc_clk[] = { |
| 123 | [SPD_375K] = { |
| 124 | .hz = 375000, |
| 125 | .scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 126 | .div_mask = 0 |
| 127 | }, |
| 128 | [SPD_390K] = { |
| 129 | .hz = 390000, |
| 130 | .scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 131 | .div_mask = 0 |
| 132 | }, |
| 133 | [SPD_187K] = { |
| 134 | .hz = 187500, |
| 135 | .scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 136 | .div_mask = 0 |
| 137 | }, |
| 138 | [SPD_200K] = { |
| 139 | .hz = 200000, |
| 140 | .scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 141 | .div_mask = 0 |
| 142 | }, |
| 143 | [SPD_93K] = { |
| 144 | .hz = 93750, |
| 145 | .scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 146 | .div_mask = BSC_CTL_REG_DIV_CLK_MASK |
| 147 | }, |
| 148 | [SPD_97K] = { |
| 149 | .hz = 97500, |
| 150 | .scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 151 | .div_mask = BSC_CTL_REG_DIV_CLK_MASK |
| 152 | }, |
| 153 | [SPD_46K] = { |
| 154 | .hz = 46875, |
| 155 | .scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 156 | .div_mask = BSC_CTL_REG_DIV_CLK_MASK |
| 157 | }, |
| 158 | [SPD_50K] = { |
| 159 | .hz = 50000, |
| 160 | .scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT, |
| 161 | .div_mask = BSC_CTL_REG_DIV_CLK_MASK |
| 162 | } |
| 163 | }; |
| 164 | |
| 165 | struct brcmstb_i2c_dev { |
| 166 | struct device *device; |
| 167 | void __iomem *base; |
| 168 | void __iomem *irq_base; |
| 169 | int irq; |
| 170 | struct bsc_regs *bsc_regmap; |
| 171 | struct i2c_adapter adapter; |
| 172 | struct completion done; |
| 173 | bool is_suspended; |
| 174 | u32 clk_freq_hz; |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 175 | int data_regsz; |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 176 | }; |
| 177 | |
| 178 | /* register accessors for both be and le cpu arch */ |
| 179 | #ifdef CONFIG_CPU_BIG_ENDIAN |
| 180 | #define __bsc_readl(_reg) ioread32be(_reg) |
| 181 | #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg) |
| 182 | #else |
| 183 | #define __bsc_readl(_reg) ioread32(_reg) |
| 184 | #define __bsc_writel(_val, _reg) iowrite32(_val, _reg) |
| 185 | #endif |
| 186 | |
| 187 | #define bsc_readl(_dev, _reg) \ |
| 188 | __bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg)) |
| 189 | |
| 190 | #define bsc_writel(_dev, _val, _reg) \ |
| 191 | __bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg)) |
| 192 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 193 | static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev) |
| 194 | { |
| 195 | return (N_DATA_REGS * dev->data_regsz); |
| 196 | } |
| 197 | |
| 198 | static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev) |
| 199 | { |
| 200 | return dev->data_regsz; |
| 201 | } |
| 202 | |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 203 | static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev, |
| 204 | bool int_en) |
| 205 | { |
| 206 | |
| 207 | if (int_en) |
| 208 | /* Enable BSC CTL interrupt line */ |
| 209 | dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK; |
| 210 | else |
| 211 | /* Disable BSC CTL interrupt line */ |
| 212 | dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK; |
| 213 | |
| 214 | barrier(); |
| 215 | bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg); |
| 216 | } |
| 217 | |
| 218 | static irqreturn_t brcmstb_i2c_isr(int irq, void *devid) |
| 219 | { |
| 220 | struct brcmstb_i2c_dev *dev = devid; |
| 221 | u32 status_bsc_ctl = bsc_readl(dev, ctl_reg); |
| 222 | u32 status_iic_intrp = bsc_readl(dev, iic_enable); |
| 223 | |
| 224 | dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n", |
| 225 | status_bsc_ctl, status_iic_intrp); |
| 226 | |
| 227 | if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK)) |
| 228 | return IRQ_NONE; |
| 229 | |
| 230 | brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE); |
| 231 | complete_all(&dev->done); |
| 232 | |
| 233 | dev_dbg(dev->device, "isr handled"); |
| 234 | return IRQ_HANDLED; |
| 235 | } |
| 236 | |
| 237 | /* Wait for device to be ready */ |
| 238 | static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev) |
| 239 | { |
| 240 | unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT); |
| 241 | |
| 242 | while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) { |
| 243 | if (time_after(jiffies, timeout)) |
| 244 | return -ETIMEDOUT; |
| 245 | cpu_relax(); |
| 246 | } |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | /* i2c xfer completion function, handles both irq and polling mode */ |
| 251 | static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev) |
| 252 | { |
| 253 | int ret = 0; |
| 254 | unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT); |
| 255 | |
| 256 | if (dev->irq >= 0) { |
| 257 | if (!wait_for_completion_timeout(&dev->done, timeout)) |
| 258 | ret = -ETIMEDOUT; |
| 259 | } else { |
| 260 | /* we are in polling mode */ |
| 261 | u32 bsc_intrp; |
| 262 | unsigned long time_left = jiffies + timeout; |
| 263 | |
| 264 | do { |
| 265 | bsc_intrp = bsc_readl(dev, iic_enable) & |
| 266 | BSC_IIC_EN_INTRP_MASK; |
| 267 | if (time_after(jiffies, time_left)) { |
| 268 | ret = -ETIMEDOUT; |
| 269 | break; |
| 270 | } |
| 271 | cpu_relax(); |
| 272 | } while (!bsc_intrp); |
| 273 | } |
| 274 | |
| 275 | if (dev->irq < 0 || ret == -ETIMEDOUT) |
| 276 | brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE); |
| 277 | |
| 278 | return ret; |
| 279 | } |
| 280 | |
| 281 | /* Set xfer START/STOP conditions for subsequent transfer */ |
| 282 | static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev, |
| 283 | u32 cond_flag) |
| 284 | { |
| 285 | u32 regval = dev->bsc_regmap->iic_enable; |
| 286 | |
| 287 | dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag; |
| 288 | } |
| 289 | |
| 290 | /* Send I2C request check completion */ |
| 291 | static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev, |
| 292 | enum bsc_xfer_cmd cmd) |
| 293 | { |
| 294 | int rc = 0; |
| 295 | struct bsc_regs *pi2creg = dev->bsc_regmap; |
| 296 | |
| 297 | /* Make sure the hardware is ready */ |
| 298 | rc = brcmstb_i2c_wait_if_busy(dev); |
| 299 | if (rc < 0) |
| 300 | return rc; |
| 301 | |
| 302 | /* only if we are in interrupt mode */ |
| 303 | if (dev->irq >= 0) |
| 304 | reinit_completion(&dev->done); |
| 305 | |
| 306 | /* enable BSC CTL interrupt line */ |
| 307 | brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE); |
| 308 | |
| 309 | /* initiate transfer by setting iic_enable */ |
| 310 | pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK; |
| 311 | bsc_writel(dev, pi2creg->iic_enable, iic_enable); |
| 312 | |
| 313 | /* Wait for transaction to finish or timeout */ |
| 314 | rc = brcmstb_i2c_wait_for_completion(dev); |
| 315 | if (rc) { |
| 316 | dev_dbg(dev->device, "intr timeout for cmd %s\n", |
| 317 | cmd_string[cmd]); |
| 318 | goto cmd_out; |
| 319 | } |
| 320 | |
| 321 | if ((CMD_RD || CMD_WR) && |
| 322 | bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) { |
| 323 | rc = -EREMOTEIO; |
| 324 | dev_dbg(dev->device, "controller received NOACK intr for %s\n", |
| 325 | cmd_string[cmd]); |
| 326 | } |
| 327 | |
| 328 | cmd_out: |
| 329 | bsc_writel(dev, 0, cnt_reg); |
| 330 | bsc_writel(dev, 0, iic_enable); |
| 331 | |
| 332 | return rc; |
| 333 | } |
| 334 | |
| 335 | /* Actual data transfer through the BSC master */ |
| 336 | static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev, |
| 337 | u8 *buf, unsigned int len, |
| 338 | struct i2c_msg *pmsg) |
| 339 | { |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 340 | int cnt, byte, i, rc; |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 341 | enum bsc_xfer_cmd cmd; |
| 342 | u32 ctl_reg; |
| 343 | struct bsc_regs *pi2creg = dev->bsc_regmap; |
| 344 | int no_ack = pmsg->flags & I2C_M_IGNORE_NAK; |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 345 | int data_regsz = brcmstb_i2c_get_data_regsz(dev); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 346 | |
| 347 | /* see if the transaction needs to check NACK conditions */ |
Jaedon Shin | 94a0b0b | 2016-07-15 12:45:09 +0900 | [diff] [blame] | 348 | if (no_ack) { |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 349 | cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK |
| 350 | : CMD_WR_NOACK; |
| 351 | pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK; |
| 352 | } else { |
| 353 | cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR; |
| 354 | pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK; |
| 355 | } |
| 356 | bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg); |
| 357 | |
| 358 | /* set data transfer direction */ |
| 359 | ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK; |
| 360 | if (cmd == CMD_WR || cmd == CMD_WR_NOACK) |
| 361 | pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK; |
| 362 | else |
| 363 | pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK; |
| 364 | |
| 365 | /* set the read/write length */ |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 366 | bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) & |
| 367 | (len << BSC_CNT_REG1_SHIFT), cnt_reg); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 368 | |
| 369 | /* Write data into data_in register */ |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 370 | |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 371 | if (cmd == CMD_WR || cmd == CMD_WR_NOACK) { |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 372 | for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) { |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 373 | u32 word = 0; |
| 374 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 375 | for (byte = 0; byte < data_regsz; byte++) { |
| 376 | word >>= BITS_PER_BYTE; |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 377 | if ((cnt + byte) < len) |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 378 | word |= buf[cnt + byte] << |
| 379 | (BITS_PER_BYTE * (data_regsz - 1)); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 380 | } |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 381 | bsc_writel(dev, word, data_in[i]); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 382 | } |
| 383 | } |
| 384 | |
| 385 | /* Initiate xfer, the function will return on completion */ |
| 386 | rc = brcmstb_send_i2c_cmd(dev, cmd); |
| 387 | |
| 388 | if (rc != 0) { |
| 389 | dev_dbg(dev->device, "%s failure", cmd_string[cmd]); |
| 390 | return rc; |
| 391 | } |
| 392 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 393 | /* Read data from data_out register */ |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 394 | if (cmd == CMD_RD || cmd == CMD_RD_NOACK) { |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 395 | for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) { |
| 396 | u32 data = bsc_readl(dev, data_out[i]); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 397 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 398 | for (byte = 0; byte < data_regsz && |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 399 | (byte + cnt) < len; byte++) { |
| 400 | buf[cnt + byte] = data & 0xff; |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 401 | data >>= BITS_PER_BYTE; |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 402 | } |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | return 0; |
| 407 | } |
| 408 | |
| 409 | /* Write a single byte of data to the i2c bus */ |
| 410 | static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev, |
| 411 | u8 *buf, unsigned int nak_expected) |
| 412 | { |
| 413 | enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK; |
| 414 | |
| 415 | bsc_writel(dev, 1, cnt_reg); |
| 416 | bsc_writel(dev, *buf, data_in); |
| 417 | |
| 418 | return brcmstb_send_i2c_cmd(dev, cmd); |
| 419 | } |
| 420 | |
| 421 | /* Send i2c address */ |
| 422 | static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev, |
| 423 | struct i2c_msg *msg) |
| 424 | { |
| 425 | unsigned char addr; |
| 426 | |
| 427 | if (msg->flags & I2C_M_TEN) { |
| 428 | /* First byte is 11110XX0 where XX is upper 2 bits */ |
| 429 | addr = 0xF0 | ((msg->addr & 0x300) >> 7); |
| 430 | bsc_writel(dev, addr, chip_address); |
| 431 | |
| 432 | /* Second byte is the remaining 8 bits */ |
| 433 | addr = msg->addr & 0xFF; |
| 434 | if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0) |
| 435 | return -EREMOTEIO; |
| 436 | |
| 437 | if (msg->flags & I2C_M_RD) { |
| 438 | /* For read, send restart without stop condition */ |
| 439 | brcmstb_set_i2c_start_stop(dev, COND_RESTART |
| 440 | | COND_NOSTOP); |
| 441 | /* Then re-send the first byte with the read bit set */ |
| 442 | addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01; |
| 443 | if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0) |
| 444 | return -EREMOTEIO; |
| 445 | |
| 446 | } |
| 447 | } else { |
Wolfram Sang | fa5ce47 | 2016-04-03 20:44:49 +0200 | [diff] [blame] | 448 | addr = i2c_8bit_addr_from_msg(msg); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 449 | |
| 450 | bsc_writel(dev, addr, chip_address); |
| 451 | } |
| 452 | |
| 453 | return 0; |
| 454 | } |
| 455 | |
| 456 | /* Master transfer function */ |
| 457 | static int brcmstb_i2c_xfer(struct i2c_adapter *adapter, |
| 458 | struct i2c_msg msgs[], int num) |
| 459 | { |
| 460 | struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter); |
| 461 | struct i2c_msg *pmsg; |
| 462 | int rc = 0; |
| 463 | int i; |
| 464 | int bytes_to_xfer; |
| 465 | u8 *tmp_buf; |
| 466 | int len = 0; |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 467 | int xfersz = brcmstb_i2c_get_xfersz(dev); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 468 | |
| 469 | if (dev->is_suspended) |
| 470 | return -EBUSY; |
| 471 | |
| 472 | /* Loop through all messages */ |
| 473 | for (i = 0; i < num; i++) { |
| 474 | pmsg = &msgs[i]; |
| 475 | len = pmsg->len; |
| 476 | tmp_buf = pmsg->buf; |
| 477 | |
| 478 | dev_dbg(dev->device, |
| 479 | "msg# %d/%d flg %x buf %x len %d\n", i, |
| 480 | num - 1, pmsg->flags, |
| 481 | pmsg->buf ? pmsg->buf[0] : '0', pmsg->len); |
| 482 | |
| 483 | if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART)) |
| 484 | brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP)); |
| 485 | else |
| 486 | brcmstb_set_i2c_start_stop(dev, |
| 487 | COND_RESTART | COND_NOSTOP); |
| 488 | |
| 489 | /* Send slave address */ |
| 490 | if (!(pmsg->flags & I2C_M_NOSTART)) { |
| 491 | rc = brcmstb_i2c_do_addr(dev, pmsg); |
| 492 | if (rc < 0) { |
| 493 | dev_dbg(dev->device, |
| 494 | "NACK for addr %2.2x msg#%d rc = %d\n", |
| 495 | pmsg->addr, i, rc); |
| 496 | goto out; |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | /* Perform data transfer */ |
| 501 | while (len) { |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 502 | bytes_to_xfer = min(len, xfersz); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 503 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 504 | if (len <= xfersz && i == (num - 1)) |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 505 | brcmstb_set_i2c_start_stop(dev, |
| 506 | ~(COND_START_STOP)); |
| 507 | |
| 508 | rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf, |
| 509 | bytes_to_xfer, pmsg); |
| 510 | if (rc < 0) |
| 511 | goto out; |
| 512 | |
| 513 | len -= bytes_to_xfer; |
| 514 | tmp_buf += bytes_to_xfer; |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | rc = num; |
| 519 | out: |
| 520 | return rc; |
| 521 | |
| 522 | } |
| 523 | |
| 524 | static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap) |
| 525 | { |
| 526 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
| 527 | | I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING; |
| 528 | } |
| 529 | |
| 530 | static const struct i2c_algorithm brcmstb_i2c_algo = { |
| 531 | .master_xfer = brcmstb_i2c_xfer, |
| 532 | .functionality = brcmstb_i2c_functionality, |
| 533 | }; |
| 534 | |
| 535 | static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev) |
| 536 | { |
| 537 | int i = 0, num_speeds = ARRAY_SIZE(bsc_clk); |
| 538 | u32 clk_freq_hz = dev->clk_freq_hz; |
| 539 | |
| 540 | for (i = 0; i < num_speeds; i++) { |
| 541 | if (bsc_clk[i].hz == clk_freq_hz) { |
| 542 | dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK |
| 543 | | BSC_CTL_REG_DIV_CLK_MASK); |
| 544 | dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask | |
| 545 | bsc_clk[i].div_mask); |
| 546 | bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg); |
| 547 | break; |
| 548 | } |
| 549 | } |
| 550 | |
| 551 | /* in case we did not get find a valid speed */ |
| 552 | if (i == num_speeds) { |
| 553 | i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >> |
| 554 | BSC_CTL_REG_SCL_SEL_SHIFT; |
| 555 | dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n", |
| 556 | bsc_clk[i].hz); |
| 557 | } |
| 558 | } |
| 559 | |
| 560 | static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev) |
| 561 | { |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 562 | if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32)) |
| 563 | /* set 4 byte data in/out xfers */ |
| 564 | dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK; |
| 565 | else |
| 566 | dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK; |
| 567 | |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 568 | bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg); |
| 569 | /* set bus speed */ |
| 570 | brcmstb_i2c_set_bus_speed(dev); |
| 571 | } |
| 572 | |
| 573 | static int brcmstb_i2c_probe(struct platform_device *pdev) |
| 574 | { |
| 575 | int rc = 0; |
| 576 | struct brcmstb_i2c_dev *dev; |
| 577 | struct i2c_adapter *adap; |
| 578 | struct resource *iomem; |
| 579 | const char *int_name; |
| 580 | |
| 581 | /* Allocate memory for private data structure */ |
| 582 | dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); |
| 583 | if (!dev) |
| 584 | return -ENOMEM; |
| 585 | |
Wolfram Sang | 7314d22 | 2016-02-21 15:16:48 +0100 | [diff] [blame] | 586 | dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(*dev->bsc_regmap), GFP_KERNEL); |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 587 | if (!dev->bsc_regmap) |
| 588 | return -ENOMEM; |
| 589 | |
| 590 | platform_set_drvdata(pdev, dev); |
| 591 | dev->device = &pdev->dev; |
| 592 | init_completion(&dev->done); |
| 593 | |
| 594 | /* Map hardware registers */ |
| 595 | iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 596 | dev->base = devm_ioremap_resource(dev->device, iomem); |
| 597 | if (IS_ERR(dev->base)) { |
| 598 | rc = -ENOMEM; |
| 599 | goto probe_errorout; |
| 600 | } |
| 601 | |
| 602 | rc = of_property_read_string(dev->device->of_node, "interrupt-names", |
| 603 | &int_name); |
| 604 | if (rc < 0) |
| 605 | int_name = NULL; |
| 606 | |
| 607 | /* Get the interrupt number */ |
| 608 | dev->irq = platform_get_irq(pdev, 0); |
| 609 | |
| 610 | /* disable the bsc interrupt line */ |
| 611 | brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE); |
| 612 | |
| 613 | /* register the ISR handler */ |
| 614 | rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr, |
| 615 | IRQF_SHARED, |
| 616 | int_name ? int_name : pdev->name, |
| 617 | dev); |
| 618 | |
| 619 | if (rc) { |
| 620 | dev_dbg(dev->device, "falling back to polling mode"); |
| 621 | dev->irq = -1; |
| 622 | } |
| 623 | |
| 624 | if (of_property_read_u32(dev->device->of_node, |
| 625 | "clock-frequency", &dev->clk_freq_hz)) { |
| 626 | dev_warn(dev->device, "setting clock-frequency@%dHz\n", |
| 627 | bsc_clk[0].hz); |
| 628 | dev->clk_freq_hz = bsc_clk[0].hz; |
| 629 | } |
| 630 | |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 631 | /* set the data in/out register size for compatible SoCs */ |
| 632 | if (of_device_is_compatible(dev->device->of_node, |
| 633 | "brcmstb,brcmper-i2c")) |
| 634 | dev->data_regsz = sizeof(u8); |
| 635 | else |
| 636 | dev->data_regsz = sizeof(u32); |
| 637 | |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 638 | brcmstb_i2c_set_bsc_reg_defaults(dev); |
| 639 | |
| 640 | /* Add the i2c adapter */ |
| 641 | adap = &dev->adapter; |
| 642 | i2c_set_adapdata(adap, dev); |
| 643 | adap->owner = THIS_MODULE; |
| 644 | strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name)); |
| 645 | if (int_name) |
| 646 | strlcat(adap->name, int_name, sizeof(adap->name)); |
| 647 | adap->algo = &brcmstb_i2c_algo; |
| 648 | adap->dev.parent = &pdev->dev; |
| 649 | adap->dev.of_node = pdev->dev.of_node; |
| 650 | rc = i2c_add_adapter(adap); |
| 651 | if (rc) { |
| 652 | dev_err(dev->device, "failed to add adapter\n"); |
| 653 | goto probe_errorout; |
| 654 | } |
| 655 | |
| 656 | dev_info(dev->device, "%s@%dhz registered in %s mode\n", |
| 657 | int_name ? int_name : " ", dev->clk_freq_hz, |
| 658 | (dev->irq >= 0) ? "interrupt" : "polling"); |
| 659 | |
| 660 | return 0; |
| 661 | |
| 662 | probe_errorout: |
| 663 | return rc; |
| 664 | } |
| 665 | |
| 666 | static int brcmstb_i2c_remove(struct platform_device *pdev) |
| 667 | { |
| 668 | struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev); |
| 669 | |
| 670 | i2c_del_adapter(&dev->adapter); |
| 671 | return 0; |
| 672 | } |
| 673 | |
| 674 | #ifdef CONFIG_PM_SLEEP |
| 675 | static int brcmstb_i2c_suspend(struct device *dev) |
| 676 | { |
| 677 | struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev); |
| 678 | |
| 679 | i2c_lock_adapter(&i2c_dev->adapter); |
| 680 | i2c_dev->is_suspended = true; |
| 681 | i2c_unlock_adapter(&i2c_dev->adapter); |
| 682 | |
| 683 | return 0; |
| 684 | } |
| 685 | |
| 686 | static int brcmstb_i2c_resume(struct device *dev) |
| 687 | { |
| 688 | struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev); |
| 689 | |
| 690 | i2c_lock_adapter(&i2c_dev->adapter); |
| 691 | brcmstb_i2c_set_bsc_reg_defaults(i2c_dev); |
| 692 | i2c_dev->is_suspended = false; |
| 693 | i2c_unlock_adapter(&i2c_dev->adapter); |
| 694 | |
| 695 | return 0; |
| 696 | } |
| 697 | #endif |
| 698 | |
| 699 | static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend, |
| 700 | brcmstb_i2c_resume); |
| 701 | |
| 702 | static const struct of_device_id brcmstb_i2c_of_match[] = { |
| 703 | {.compatible = "brcm,brcmstb-i2c"}, |
Kamal Dasu | e2e5a2c | 2015-12-16 15:49:09 -0500 | [diff] [blame] | 704 | {.compatible = "brcm,brcmper-i2c"}, |
Kamal Dasu | dd1aa25 | 2015-06-09 15:36:20 -0400 | [diff] [blame] | 705 | {}, |
| 706 | }; |
| 707 | MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match); |
| 708 | |
| 709 | static struct platform_driver brcmstb_i2c_driver = { |
| 710 | .driver = { |
| 711 | .name = "brcmstb-i2c", |
| 712 | .of_match_table = brcmstb_i2c_of_match, |
| 713 | .pm = &brcmstb_i2c_pm, |
| 714 | }, |
| 715 | .probe = brcmstb_i2c_probe, |
| 716 | .remove = brcmstb_i2c_remove, |
| 717 | }; |
| 718 | module_platform_driver(brcmstb_i2c_driver); |
| 719 | |
| 720 | MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>"); |
| 721 | MODULE_DESCRIPTION("Broadcom Settop I2C Driver"); |
| 722 | MODULE_LICENSE("GPL v2"); |