Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 1 | /* |
| 2 | * i2c Support for Atmel's AT91 Two-Wire Interface (TWI) |
| 3 | * |
| 4 | * Copyright (C) 2011 Weinmann Medical GmbH |
| 5 | * Author: Nikolaus Voss <n.voss@weinmann.de> |
| 6 | * |
| 7 | * Evolved from original work by: |
| 8 | * Copyright (C) 2004 Rick Bronson |
| 9 | * Converted to 2.6 by Andrew Victor <andrew@sanpeople.com> |
| 10 | * |
| 11 | * Borrowed heavily from original work by: |
| 12 | * Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com> |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | */ |
| 19 | |
| 20 | #include <linux/clk.h> |
| 21 | #include <linux/completion.h> |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 22 | #include <linux/dma-mapping.h> |
| 23 | #include <linux/dmaengine.h> |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 24 | #include <linux/err.h> |
| 25 | #include <linux/i2c.h> |
| 26 | #include <linux/interrupt.h> |
| 27 | #include <linux/io.h> |
| 28 | #include <linux/module.h> |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 29 | #include <linux/of.h> |
| 30 | #include <linux/of_device.h> |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 31 | #include <linux/platform_device.h> |
| 32 | #include <linux/slab.h> |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 33 | #include <linux/platform_data/dma-atmel.h> |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 34 | |
Marek Roszko | 75b6c4b | 2014-03-11 00:25:38 -0400 | [diff] [blame] | 35 | #define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */ |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 36 | #define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */ |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 37 | #define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */ |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 38 | |
| 39 | /* AT91 TWI register definitions */ |
| 40 | #define AT91_TWI_CR 0x0000 /* Control Register */ |
| 41 | #define AT91_TWI_START 0x0001 /* Send a Start Condition */ |
| 42 | #define AT91_TWI_STOP 0x0002 /* Send a Stop Condition */ |
| 43 | #define AT91_TWI_MSEN 0x0004 /* Master Transfer Enable */ |
| 44 | #define AT91_TWI_SVDIS 0x0020 /* Slave Transfer Disable */ |
Ludovic Desroches | 7c3fe64 | 2012-11-13 16:43:21 +0100 | [diff] [blame] | 45 | #define AT91_TWI_QUICK 0x0040 /* SMBus quick command */ |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 46 | #define AT91_TWI_SWRST 0x0080 /* Software Reset */ |
| 47 | |
| 48 | #define AT91_TWI_MMR 0x0004 /* Master Mode Register */ |
| 49 | #define AT91_TWI_IADRSZ_1 0x0100 /* Internal Device Address Size */ |
| 50 | #define AT91_TWI_MREAD 0x1000 /* Master Read Direction */ |
| 51 | |
| 52 | #define AT91_TWI_IADR 0x000c /* Internal Address Register */ |
| 53 | |
| 54 | #define AT91_TWI_CWGR 0x0010 /* Clock Waveform Generator Reg */ |
| 55 | |
| 56 | #define AT91_TWI_SR 0x0020 /* Status Register */ |
| 57 | #define AT91_TWI_TXCOMP 0x0001 /* Transmission Complete */ |
| 58 | #define AT91_TWI_RXRDY 0x0002 /* Receive Holding Register Ready */ |
| 59 | #define AT91_TWI_TXRDY 0x0004 /* Transmit Holding Register Ready */ |
| 60 | |
| 61 | #define AT91_TWI_OVRE 0x0040 /* Overrun Error */ |
| 62 | #define AT91_TWI_UNRE 0x0080 /* Underrun Error */ |
| 63 | #define AT91_TWI_NACK 0x0100 /* Not Acknowledged */ |
| 64 | |
| 65 | #define AT91_TWI_IER 0x0024 /* Interrupt Enable Register */ |
| 66 | #define AT91_TWI_IDR 0x0028 /* Interrupt Disable Register */ |
| 67 | #define AT91_TWI_IMR 0x002c /* Interrupt Mask Register */ |
| 68 | #define AT91_TWI_RHR 0x0030 /* Receive Holding Register */ |
| 69 | #define AT91_TWI_THR 0x0034 /* Transmit Holding Register */ |
| 70 | |
| 71 | struct at91_twi_pdata { |
Ludovic Desroches | 5f43381 | 2012-11-23 10:09:03 +0100 | [diff] [blame] | 72 | unsigned clk_max_div; |
| 73 | unsigned clk_offset; |
| 74 | bool has_unre_flag; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 75 | bool has_dma_support; |
| 76 | struct at_dma_slave dma_slave; |
| 77 | }; |
| 78 | |
| 79 | struct at91_twi_dma { |
| 80 | struct dma_chan *chan_rx; |
| 81 | struct dma_chan *chan_tx; |
| 82 | struct scatterlist sg; |
| 83 | struct dma_async_tx_descriptor *data_desc; |
| 84 | enum dma_data_direction direction; |
| 85 | bool buf_mapped; |
| 86 | bool xfer_in_progress; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 87 | }; |
| 88 | |
| 89 | struct at91_twi_dev { |
Ludovic Desroches | 5f43381 | 2012-11-23 10:09:03 +0100 | [diff] [blame] | 90 | struct device *dev; |
| 91 | void __iomem *base; |
| 92 | struct completion cmd_complete; |
| 93 | struct clk *clk; |
| 94 | u8 *buf; |
| 95 | size_t buf_len; |
| 96 | struct i2c_msg *msg; |
| 97 | int irq; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 98 | unsigned imr; |
Ludovic Desroches | 5f43381 | 2012-11-23 10:09:03 +0100 | [diff] [blame] | 99 | unsigned transfer_status; |
| 100 | struct i2c_adapter adapter; |
| 101 | unsigned twi_cwgr_reg; |
| 102 | struct at91_twi_pdata *pdata; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 103 | bool use_dma; |
Marek Roszko | 75b81f3 | 2014-08-20 21:39:41 -0400 | [diff] [blame] | 104 | bool recv_len_abort; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 105 | struct at91_twi_dma dma; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 106 | }; |
| 107 | |
| 108 | static unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg) |
| 109 | { |
| 110 | return readl_relaxed(dev->base + reg); |
| 111 | } |
| 112 | |
| 113 | static void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) |
| 114 | { |
| 115 | writel_relaxed(val, dev->base + reg); |
| 116 | } |
| 117 | |
| 118 | static void at91_disable_twi_interrupts(struct at91_twi_dev *dev) |
| 119 | { |
| 120 | at91_twi_write(dev, AT91_TWI_IDR, |
| 121 | AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY); |
| 122 | } |
| 123 | |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 124 | static void at91_twi_irq_save(struct at91_twi_dev *dev) |
| 125 | { |
| 126 | dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & 0x7; |
| 127 | at91_disable_twi_interrupts(dev); |
| 128 | } |
| 129 | |
| 130 | static void at91_twi_irq_restore(struct at91_twi_dev *dev) |
| 131 | { |
| 132 | at91_twi_write(dev, AT91_TWI_IER, dev->imr); |
| 133 | } |
| 134 | |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 135 | static void at91_init_twi_bus(struct at91_twi_dev *dev) |
| 136 | { |
| 137 | at91_disable_twi_interrupts(dev); |
| 138 | at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST); |
| 139 | at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN); |
| 140 | at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS); |
| 141 | at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg); |
| 142 | } |
| 143 | |
| 144 | /* |
| 145 | * Calculate symmetric clock as stated in datasheet: |
| 146 | * twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset)) |
| 147 | */ |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 148 | static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 149 | { |
| 150 | int ckdiv, cdiv, div; |
| 151 | struct at91_twi_pdata *pdata = dev->pdata; |
| 152 | int offset = pdata->clk_offset; |
| 153 | int max_ckdiv = pdata->clk_max_div; |
| 154 | |
| 155 | div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk), |
| 156 | 2 * twi_clk) - offset); |
| 157 | ckdiv = fls(div >> 8); |
| 158 | cdiv = div >> ckdiv; |
| 159 | |
| 160 | if (ckdiv > max_ckdiv) { |
| 161 | dev_warn(dev->dev, "%d exceeds ckdiv max value which is %d.\n", |
| 162 | ckdiv, max_ckdiv); |
| 163 | ckdiv = max_ckdiv; |
| 164 | cdiv = 255; |
| 165 | } |
| 166 | |
| 167 | dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv; |
| 168 | dev_dbg(dev->dev, "cdiv %d ckdiv %d\n", cdiv, ckdiv); |
| 169 | } |
| 170 | |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 171 | static void at91_twi_dma_cleanup(struct at91_twi_dev *dev) |
| 172 | { |
| 173 | struct at91_twi_dma *dma = &dev->dma; |
| 174 | |
| 175 | at91_twi_irq_save(dev); |
| 176 | |
| 177 | if (dma->xfer_in_progress) { |
| 178 | if (dma->direction == DMA_FROM_DEVICE) |
| 179 | dmaengine_terminate_all(dma->chan_rx); |
| 180 | else |
| 181 | dmaengine_terminate_all(dma->chan_tx); |
| 182 | dma->xfer_in_progress = false; |
| 183 | } |
| 184 | if (dma->buf_mapped) { |
| 185 | dma_unmap_single(dev->dev, sg_dma_address(&dma->sg), |
| 186 | dev->buf_len, dma->direction); |
| 187 | dma->buf_mapped = false; |
| 188 | } |
| 189 | |
| 190 | at91_twi_irq_restore(dev); |
| 191 | } |
| 192 | |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 193 | static void at91_twi_write_next_byte(struct at91_twi_dev *dev) |
| 194 | { |
| 195 | if (dev->buf_len <= 0) |
| 196 | return; |
| 197 | |
| 198 | at91_twi_write(dev, AT91_TWI_THR, *dev->buf); |
| 199 | |
| 200 | /* send stop when last byte has been written */ |
| 201 | if (--dev->buf_len == 0) |
| 202 | at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); |
| 203 | |
| 204 | dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len); |
| 205 | |
| 206 | ++dev->buf; |
| 207 | } |
| 208 | |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 209 | static void at91_twi_write_data_dma_callback(void *data) |
| 210 | { |
| 211 | struct at91_twi_dev *dev = (struct at91_twi_dev *)data; |
| 212 | |
| 213 | dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg), |
Wolfram Sang | 28772ac | 2014-07-21 11:42:03 +0200 | [diff] [blame] | 214 | dev->buf_len, DMA_TO_DEVICE); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 215 | |
| 216 | at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); |
| 217 | } |
| 218 | |
| 219 | static void at91_twi_write_data_dma(struct at91_twi_dev *dev) |
| 220 | { |
| 221 | dma_addr_t dma_addr; |
| 222 | struct dma_async_tx_descriptor *txdesc; |
| 223 | struct at91_twi_dma *dma = &dev->dma; |
| 224 | struct dma_chan *chan_tx = dma->chan_tx; |
| 225 | |
| 226 | if (dev->buf_len <= 0) |
| 227 | return; |
| 228 | |
| 229 | dma->direction = DMA_TO_DEVICE; |
| 230 | |
| 231 | at91_twi_irq_save(dev); |
| 232 | dma_addr = dma_map_single(dev->dev, dev->buf, dev->buf_len, |
| 233 | DMA_TO_DEVICE); |
| 234 | if (dma_mapping_error(dev->dev, dma_addr)) { |
| 235 | dev_err(dev->dev, "dma map failed\n"); |
| 236 | return; |
| 237 | } |
| 238 | dma->buf_mapped = true; |
| 239 | at91_twi_irq_restore(dev); |
| 240 | sg_dma_len(&dma->sg) = dev->buf_len; |
| 241 | sg_dma_address(&dma->sg) = dma_addr; |
| 242 | |
| 243 | txdesc = dmaengine_prep_slave_sg(chan_tx, &dma->sg, 1, DMA_MEM_TO_DEV, |
| 244 | DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
| 245 | if (!txdesc) { |
| 246 | dev_err(dev->dev, "dma prep slave sg failed\n"); |
| 247 | goto error; |
| 248 | } |
| 249 | |
| 250 | txdesc->callback = at91_twi_write_data_dma_callback; |
| 251 | txdesc->callback_param = dev; |
| 252 | |
| 253 | dma->xfer_in_progress = true; |
| 254 | dmaengine_submit(txdesc); |
| 255 | dma_async_issue_pending(chan_tx); |
| 256 | |
| 257 | return; |
| 258 | |
| 259 | error: |
| 260 | at91_twi_dma_cleanup(dev); |
| 261 | } |
| 262 | |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 263 | static void at91_twi_read_next_byte(struct at91_twi_dev *dev) |
| 264 | { |
| 265 | if (dev->buf_len <= 0) |
| 266 | return; |
| 267 | |
| 268 | *dev->buf = at91_twi_read(dev, AT91_TWI_RHR) & 0xff; |
| 269 | --dev->buf_len; |
| 270 | |
Marek Roszko | 75b81f3 | 2014-08-20 21:39:41 -0400 | [diff] [blame] | 271 | /* return if aborting, we only needed to read RHR to clear RXRDY*/ |
| 272 | if (dev->recv_len_abort) |
| 273 | return; |
| 274 | |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 275 | /* handle I2C_SMBUS_BLOCK_DATA */ |
| 276 | if (unlikely(dev->msg->flags & I2C_M_RECV_LEN)) { |
Marek Roszko | 75b81f3 | 2014-08-20 21:39:41 -0400 | [diff] [blame] | 277 | /* ensure length byte is a valid value */ |
| 278 | if (*dev->buf <= I2C_SMBUS_BLOCK_MAX && *dev->buf > 0) { |
| 279 | dev->msg->flags &= ~I2C_M_RECV_LEN; |
| 280 | dev->buf_len += *dev->buf; |
| 281 | dev->msg->len = dev->buf_len + 1; |
| 282 | dev_dbg(dev->dev, "received block length %d\n", |
| 283 | dev->buf_len); |
| 284 | } else { |
| 285 | /* abort and send the stop by reading one more byte */ |
| 286 | dev->recv_len_abort = true; |
| 287 | dev->buf_len = 1; |
| 288 | } |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 289 | } |
| 290 | |
| 291 | /* send stop if second but last byte has been read */ |
| 292 | if (dev->buf_len == 1) |
| 293 | at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); |
| 294 | |
| 295 | dev_dbg(dev->dev, "read 0x%x, to go %d\n", *dev->buf, dev->buf_len); |
| 296 | |
| 297 | ++dev->buf; |
| 298 | } |
| 299 | |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 300 | static void at91_twi_read_data_dma_callback(void *data) |
| 301 | { |
| 302 | struct at91_twi_dev *dev = (struct at91_twi_dev *)data; |
| 303 | |
| 304 | dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg), |
Wolfram Sang | 28772ac | 2014-07-21 11:42:03 +0200 | [diff] [blame] | 305 | dev->buf_len, DMA_FROM_DEVICE); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 306 | |
| 307 | /* The last two bytes have to be read without using dma */ |
| 308 | dev->buf += dev->buf_len - 2; |
| 309 | dev->buf_len = 2; |
| 310 | at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_RXRDY); |
| 311 | } |
| 312 | |
| 313 | static void at91_twi_read_data_dma(struct at91_twi_dev *dev) |
| 314 | { |
| 315 | dma_addr_t dma_addr; |
| 316 | struct dma_async_tx_descriptor *rxdesc; |
| 317 | struct at91_twi_dma *dma = &dev->dma; |
| 318 | struct dma_chan *chan_rx = dma->chan_rx; |
| 319 | |
| 320 | dma->direction = DMA_FROM_DEVICE; |
| 321 | |
| 322 | /* Keep in mind that we won't use dma to read the last two bytes */ |
| 323 | at91_twi_irq_save(dev); |
| 324 | dma_addr = dma_map_single(dev->dev, dev->buf, dev->buf_len - 2, |
| 325 | DMA_FROM_DEVICE); |
| 326 | if (dma_mapping_error(dev->dev, dma_addr)) { |
| 327 | dev_err(dev->dev, "dma map failed\n"); |
| 328 | return; |
| 329 | } |
| 330 | dma->buf_mapped = true; |
| 331 | at91_twi_irq_restore(dev); |
| 332 | dma->sg.dma_address = dma_addr; |
| 333 | sg_dma_len(&dma->sg) = dev->buf_len - 2; |
| 334 | |
| 335 | rxdesc = dmaengine_prep_slave_sg(chan_rx, &dma->sg, 1, DMA_DEV_TO_MEM, |
| 336 | DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
| 337 | if (!rxdesc) { |
| 338 | dev_err(dev->dev, "dma prep slave sg failed\n"); |
| 339 | goto error; |
| 340 | } |
| 341 | |
| 342 | rxdesc->callback = at91_twi_read_data_dma_callback; |
| 343 | rxdesc->callback_param = dev; |
| 344 | |
| 345 | dma->xfer_in_progress = true; |
| 346 | dmaengine_submit(rxdesc); |
| 347 | dma_async_issue_pending(dma->chan_rx); |
| 348 | |
| 349 | return; |
| 350 | |
| 351 | error: |
| 352 | at91_twi_dma_cleanup(dev); |
| 353 | } |
| 354 | |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 355 | static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id) |
| 356 | { |
| 357 | struct at91_twi_dev *dev = dev_id; |
| 358 | const unsigned status = at91_twi_read(dev, AT91_TWI_SR); |
| 359 | const unsigned irqstatus = status & at91_twi_read(dev, AT91_TWI_IMR); |
| 360 | |
| 361 | if (!irqstatus) |
| 362 | return IRQ_NONE; |
| 363 | else if (irqstatus & AT91_TWI_RXRDY) |
| 364 | at91_twi_read_next_byte(dev); |
| 365 | else if (irqstatus & AT91_TWI_TXRDY) |
| 366 | at91_twi_write_next_byte(dev); |
| 367 | |
| 368 | /* catch error flags */ |
| 369 | dev->transfer_status |= status; |
| 370 | |
| 371 | if (irqstatus & AT91_TWI_TXCOMP) { |
| 372 | at91_disable_twi_interrupts(dev); |
| 373 | complete(&dev->cmd_complete); |
| 374 | } |
| 375 | |
| 376 | return IRQ_HANDLED; |
| 377 | } |
| 378 | |
| 379 | static int at91_do_twi_transfer(struct at91_twi_dev *dev) |
| 380 | { |
| 381 | int ret; |
| 382 | bool has_unre_flag = dev->pdata->has_unre_flag; |
| 383 | |
| 384 | dev_dbg(dev->dev, "transfer: %s %d bytes.\n", |
| 385 | (dev->msg->flags & I2C_M_RD) ? "read" : "write", dev->buf_len); |
| 386 | |
Wolfram Sang | 16735d0 | 2013-11-14 14:32:02 -0800 | [diff] [blame] | 387 | reinit_completion(&dev->cmd_complete); |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 388 | dev->transfer_status = 0; |
Ludovic Desroches | 7c3fe64 | 2012-11-13 16:43:21 +0100 | [diff] [blame] | 389 | |
| 390 | if (!dev->buf_len) { |
| 391 | at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_QUICK); |
| 392 | at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP); |
| 393 | } else if (dev->msg->flags & I2C_M_RD) { |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 394 | unsigned start_flags = AT91_TWI_START; |
| 395 | |
| 396 | if (at91_twi_read(dev, AT91_TWI_SR) & AT91_TWI_RXRDY) { |
| 397 | dev_err(dev->dev, "RXRDY still set!"); |
| 398 | at91_twi_read(dev, AT91_TWI_RHR); |
| 399 | } |
| 400 | |
| 401 | /* if only one byte is to be read, immediately stop transfer */ |
| 402 | if (dev->buf_len <= 1 && !(dev->msg->flags & I2C_M_RECV_LEN)) |
| 403 | start_flags |= AT91_TWI_STOP; |
| 404 | at91_twi_write(dev, AT91_TWI_CR, start_flags); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 405 | /* |
| 406 | * When using dma, the last byte has to be read manually in |
| 407 | * order to not send the stop command too late and then |
| 408 | * to receive extra data. In practice, there are some issues |
| 409 | * if you use the dma to read n-1 bytes because of latency. |
| 410 | * Reading n-2 bytes with dma and the two last ones manually |
| 411 | * seems to be the best solution. |
| 412 | */ |
| 413 | if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) { |
| 414 | at91_twi_read_data_dma(dev); |
| 415 | /* |
| 416 | * It is important to enable TXCOMP irq here because |
| 417 | * doing it only when transferring the last two bytes |
| 418 | * will mask NACK errors since TXCOMP is set when a |
| 419 | * NACK occurs. |
| 420 | */ |
| 421 | at91_twi_write(dev, AT91_TWI_IER, |
| 422 | AT91_TWI_TXCOMP); |
| 423 | } else |
| 424 | at91_twi_write(dev, AT91_TWI_IER, |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 425 | AT91_TWI_TXCOMP | AT91_TWI_RXRDY); |
| 426 | } else { |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 427 | if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) { |
| 428 | at91_twi_write_data_dma(dev); |
| 429 | at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP); |
| 430 | } else { |
| 431 | at91_twi_write_next_byte(dev); |
| 432 | at91_twi_write(dev, AT91_TWI_IER, |
| 433 | AT91_TWI_TXCOMP | AT91_TWI_TXRDY); |
| 434 | } |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 435 | } |
| 436 | |
Wolfram Sang | 11cfbfb | 2014-11-03 21:16:16 +0100 | [diff] [blame] | 437 | ret = wait_for_completion_timeout(&dev->cmd_complete, |
Simon Lindgren | 6721f28 | 2014-08-26 21:13:24 +0200 | [diff] [blame] | 438 | dev->adapter.timeout); |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 439 | if (ret == 0) { |
| 440 | dev_err(dev->dev, "controller timed out\n"); |
| 441 | at91_init_twi_bus(dev); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 442 | ret = -ETIMEDOUT; |
| 443 | goto error; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 444 | } |
| 445 | if (dev->transfer_status & AT91_TWI_NACK) { |
| 446 | dev_dbg(dev->dev, "received nack\n"); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 447 | ret = -EREMOTEIO; |
| 448 | goto error; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 449 | } |
| 450 | if (dev->transfer_status & AT91_TWI_OVRE) { |
| 451 | dev_err(dev->dev, "overrun while reading\n"); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 452 | ret = -EIO; |
| 453 | goto error; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 454 | } |
| 455 | if (has_unre_flag && dev->transfer_status & AT91_TWI_UNRE) { |
| 456 | dev_err(dev->dev, "underrun while writing\n"); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 457 | ret = -EIO; |
| 458 | goto error; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 459 | } |
Marek Roszko | 75b81f3 | 2014-08-20 21:39:41 -0400 | [diff] [blame] | 460 | if (dev->recv_len_abort) { |
| 461 | dev_err(dev->dev, "invalid smbus block length recvd\n"); |
| 462 | ret = -EPROTO; |
| 463 | goto error; |
| 464 | } |
| 465 | |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 466 | dev_dbg(dev->dev, "transfer complete\n"); |
| 467 | |
| 468 | return 0; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 469 | |
| 470 | error: |
| 471 | at91_twi_dma_cleanup(dev); |
| 472 | return ret; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 473 | } |
| 474 | |
| 475 | static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) |
| 476 | { |
| 477 | struct at91_twi_dev *dev = i2c_get_adapdata(adap); |
| 478 | int ret; |
| 479 | unsigned int_addr_flag = 0; |
| 480 | struct i2c_msg *m_start = msg; |
| 481 | |
| 482 | dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num); |
| 483 | |
| 484 | /* |
| 485 | * The hardware can handle at most two messages concatenated by a |
| 486 | * repeated start via it's internal address feature. |
| 487 | */ |
| 488 | if (num > 2) { |
| 489 | dev_err(dev->dev, |
| 490 | "cannot handle more than two concatenated messages.\n"); |
| 491 | return 0; |
| 492 | } else if (num == 2) { |
| 493 | int internal_address = 0; |
| 494 | int i; |
| 495 | |
| 496 | if (msg->flags & I2C_M_RD) { |
| 497 | dev_err(dev->dev, "first transfer must be write.\n"); |
| 498 | return -EINVAL; |
| 499 | } |
| 500 | if (msg->len > 3) { |
| 501 | dev_err(dev->dev, "first message size must be <= 3.\n"); |
| 502 | return -EINVAL; |
| 503 | } |
| 504 | |
| 505 | /* 1st msg is put into the internal address, start with 2nd */ |
| 506 | m_start = &msg[1]; |
| 507 | for (i = 0; i < msg->len; ++i) { |
| 508 | const unsigned addr = msg->buf[msg->len - 1 - i]; |
| 509 | |
| 510 | internal_address |= addr << (8 * i); |
| 511 | int_addr_flag += AT91_TWI_IADRSZ_1; |
| 512 | } |
| 513 | at91_twi_write(dev, AT91_TWI_IADR, internal_address); |
| 514 | } |
| 515 | |
| 516 | at91_twi_write(dev, AT91_TWI_MMR, (m_start->addr << 16) | int_addr_flag |
| 517 | | ((m_start->flags & I2C_M_RD) ? AT91_TWI_MREAD : 0)); |
| 518 | |
| 519 | dev->buf_len = m_start->len; |
| 520 | dev->buf = m_start->buf; |
| 521 | dev->msg = m_start; |
Marek Roszko | 75b81f3 | 2014-08-20 21:39:41 -0400 | [diff] [blame] | 522 | dev->recv_len_abort = false; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 523 | |
| 524 | ret = at91_do_twi_transfer(dev); |
| 525 | |
| 526 | return (ret < 0) ? ret : num; |
| 527 | } |
| 528 | |
| 529 | static u32 at91_twi_func(struct i2c_adapter *adapter) |
| 530 | { |
| 531 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
| 532 | | I2C_FUNC_SMBUS_READ_BLOCK_DATA; |
| 533 | } |
| 534 | |
| 535 | static struct i2c_algorithm at91_twi_algorithm = { |
| 536 | .master_xfer = at91_twi_xfer, |
| 537 | .functionality = at91_twi_func, |
| 538 | }; |
| 539 | |
| 540 | static struct at91_twi_pdata at91rm9200_config = { |
| 541 | .clk_max_div = 5, |
| 542 | .clk_offset = 3, |
| 543 | .has_unre_flag = true, |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 544 | .has_dma_support = false, |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 545 | }; |
| 546 | |
| 547 | static struct at91_twi_pdata at91sam9261_config = { |
| 548 | .clk_max_div = 5, |
| 549 | .clk_offset = 4, |
| 550 | .has_unre_flag = false, |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 551 | .has_dma_support = false, |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 552 | }; |
| 553 | |
| 554 | static struct at91_twi_pdata at91sam9260_config = { |
| 555 | .clk_max_div = 7, |
| 556 | .clk_offset = 4, |
| 557 | .has_unre_flag = false, |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 558 | .has_dma_support = false, |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 559 | }; |
| 560 | |
| 561 | static struct at91_twi_pdata at91sam9g20_config = { |
| 562 | .clk_max_div = 7, |
| 563 | .clk_offset = 4, |
| 564 | .has_unre_flag = false, |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 565 | .has_dma_support = false, |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 566 | }; |
| 567 | |
| 568 | static struct at91_twi_pdata at91sam9g10_config = { |
| 569 | .clk_max_div = 7, |
| 570 | .clk_offset = 4, |
| 571 | .has_unre_flag = false, |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 572 | .has_dma_support = false, |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 573 | }; |
| 574 | |
| 575 | static const struct platform_device_id at91_twi_devtypes[] = { |
| 576 | { |
| 577 | .name = "i2c-at91rm9200", |
| 578 | .driver_data = (unsigned long) &at91rm9200_config, |
| 579 | }, { |
| 580 | .name = "i2c-at91sam9261", |
| 581 | .driver_data = (unsigned long) &at91sam9261_config, |
| 582 | }, { |
| 583 | .name = "i2c-at91sam9260", |
| 584 | .driver_data = (unsigned long) &at91sam9260_config, |
| 585 | }, { |
| 586 | .name = "i2c-at91sam9g20", |
| 587 | .driver_data = (unsigned long) &at91sam9g20_config, |
| 588 | }, { |
| 589 | .name = "i2c-at91sam9g10", |
| 590 | .driver_data = (unsigned long) &at91sam9g10_config, |
| 591 | }, { |
| 592 | /* sentinel */ |
| 593 | } |
| 594 | }; |
| 595 | |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 596 | #if defined(CONFIG_OF) |
Joachim Eastwood | 4182b43 | 2013-02-09 19:14:00 +0100 | [diff] [blame] | 597 | static struct at91_twi_pdata at91sam9x5_config = { |
| 598 | .clk_max_div = 7, |
| 599 | .clk_offset = 4, |
| 600 | .has_unre_flag = false, |
| 601 | .has_dma_support = true, |
| 602 | }; |
| 603 | |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 604 | static const struct of_device_id atmel_twi_dt_ids[] = { |
| 605 | { |
Joachim Eastwood | 631056c | 2012-12-05 22:42:12 +0100 | [diff] [blame] | 606 | .compatible = "atmel,at91rm9200-i2c", |
| 607 | .data = &at91rm9200_config, |
| 608 | } , { |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 609 | .compatible = "atmel,at91sam9260-i2c", |
| 610 | .data = &at91sam9260_config, |
| 611 | } , { |
jean-jacques hiblot | d9a3afc | 2014-01-15 14:17:13 +0100 | [diff] [blame] | 612 | .compatible = "atmel,at91sam9261-i2c", |
| 613 | .data = &at91sam9261_config, |
| 614 | } , { |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 615 | .compatible = "atmel,at91sam9g20-i2c", |
| 616 | .data = &at91sam9g20_config, |
| 617 | } , { |
| 618 | .compatible = "atmel,at91sam9g10-i2c", |
| 619 | .data = &at91sam9g10_config, |
| 620 | }, { |
| 621 | .compatible = "atmel,at91sam9x5-i2c", |
| 622 | .data = &at91sam9x5_config, |
| 623 | }, { |
| 624 | /* sentinel */ |
| 625 | } |
| 626 | }; |
| 627 | MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids); |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 628 | #endif |
| 629 | |
Ludovic Desroches | d877a72 | 2013-04-15 02:16:56 +0000 | [diff] [blame] | 630 | static bool filter(struct dma_chan *chan, void *pdata) |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 631 | { |
Ludovic Desroches | d877a72 | 2013-04-15 02:16:56 +0000 | [diff] [blame] | 632 | struct at91_twi_pdata *sl_pdata = pdata; |
| 633 | struct at_dma_slave *sl; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 634 | |
Ludovic Desroches | d877a72 | 2013-04-15 02:16:56 +0000 | [diff] [blame] | 635 | if (!sl_pdata) |
| 636 | return false; |
| 637 | |
| 638 | sl = &sl_pdata->dma_slave; |
| 639 | if (sl && (sl->dma_dev == chan->device->dev)) { |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 640 | chan->private = sl; |
| 641 | return true; |
| 642 | } else { |
| 643 | return false; |
| 644 | } |
| 645 | } |
| 646 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 647 | static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 648 | { |
| 649 | int ret = 0; |
Ludovic Desroches | d877a72 | 2013-04-15 02:16:56 +0000 | [diff] [blame] | 650 | struct at91_twi_pdata *pdata = dev->pdata; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 651 | struct dma_slave_config slave_config; |
| 652 | struct at91_twi_dma *dma = &dev->dma; |
Ludovic Desroches | d877a72 | 2013-04-15 02:16:56 +0000 | [diff] [blame] | 653 | dma_cap_mask_t mask; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 654 | |
| 655 | memset(&slave_config, 0, sizeof(slave_config)); |
| 656 | slave_config.src_addr = (dma_addr_t)phy_addr + AT91_TWI_RHR; |
| 657 | slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; |
| 658 | slave_config.src_maxburst = 1; |
| 659 | slave_config.dst_addr = (dma_addr_t)phy_addr + AT91_TWI_THR; |
| 660 | slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; |
| 661 | slave_config.dst_maxburst = 1; |
| 662 | slave_config.device_fc = false; |
| 663 | |
Ludovic Desroches | d877a72 | 2013-04-15 02:16:56 +0000 | [diff] [blame] | 664 | dma_cap_zero(mask); |
| 665 | dma_cap_set(DMA_SLAVE, mask); |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 666 | |
Ludovic Desroches | d877a72 | 2013-04-15 02:16:56 +0000 | [diff] [blame] | 667 | dma->chan_tx = dma_request_slave_channel_compat(mask, filter, pdata, |
| 668 | dev->dev, "tx"); |
| 669 | if (!dma->chan_tx) { |
| 670 | dev_err(dev->dev, "can't get a DMA channel for tx\n"); |
| 671 | ret = -EBUSY; |
| 672 | goto error; |
| 673 | } |
| 674 | |
| 675 | dma->chan_rx = dma_request_slave_channel_compat(mask, filter, pdata, |
| 676 | dev->dev, "rx"); |
| 677 | if (!dma->chan_rx) { |
| 678 | dev_err(dev->dev, "can't get a DMA channel for rx\n"); |
| 679 | ret = -EBUSY; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 680 | goto error; |
| 681 | } |
| 682 | |
| 683 | slave_config.direction = DMA_MEM_TO_DEV; |
| 684 | if (dmaengine_slave_config(dma->chan_tx, &slave_config)) { |
| 685 | dev_err(dev->dev, "failed to configure tx channel\n"); |
| 686 | ret = -EINVAL; |
| 687 | goto error; |
| 688 | } |
| 689 | |
| 690 | slave_config.direction = DMA_DEV_TO_MEM; |
| 691 | if (dmaengine_slave_config(dma->chan_rx, &slave_config)) { |
| 692 | dev_err(dev->dev, "failed to configure rx channel\n"); |
| 693 | ret = -EINVAL; |
| 694 | goto error; |
| 695 | } |
| 696 | |
| 697 | sg_init_table(&dma->sg, 1); |
| 698 | dma->buf_mapped = false; |
| 699 | dma->xfer_in_progress = false; |
| 700 | |
| 701 | dev_info(dev->dev, "using %s (tx) and %s (rx) for DMA transfers\n", |
| 702 | dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); |
| 703 | |
| 704 | return ret; |
| 705 | |
| 706 | error: |
| 707 | dev_info(dev->dev, "can't use DMA\n"); |
| 708 | if (dma->chan_rx) |
| 709 | dma_release_channel(dma->chan_rx); |
| 710 | if (dma->chan_tx) |
| 711 | dma_release_channel(dma->chan_tx); |
| 712 | return ret; |
| 713 | } |
| 714 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 715 | static struct at91_twi_pdata *at91_twi_get_driver_data( |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 716 | struct platform_device *pdev) |
| 717 | { |
| 718 | if (pdev->dev.of_node) { |
| 719 | const struct of_device_id *match; |
| 720 | match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node); |
| 721 | if (!match) |
| 722 | return NULL; |
Ludovic Desroches | cd32e6c | 2012-11-23 17:03:16 +0100 | [diff] [blame] | 723 | return (struct at91_twi_pdata *)match->data; |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 724 | } |
| 725 | return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data; |
| 726 | } |
| 727 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 728 | static int at91_twi_probe(struct platform_device *pdev) |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 729 | { |
| 730 | struct at91_twi_dev *dev; |
| 731 | struct resource *mem; |
| 732 | int rc; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 733 | u32 phy_addr; |
Marek Roszko | 75b6c4b | 2014-03-11 00:25:38 -0400 | [diff] [blame] | 734 | u32 bus_clk_rate; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 735 | |
| 736 | dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); |
| 737 | if (!dev) |
| 738 | return -ENOMEM; |
| 739 | init_completion(&dev->cmd_complete); |
| 740 | dev->dev = &pdev->dev; |
| 741 | |
| 742 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 743 | if (!mem) |
| 744 | return -ENODEV; |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 745 | phy_addr = mem->start; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 746 | |
| 747 | dev->pdata = at91_twi_get_driver_data(pdev); |
| 748 | if (!dev->pdata) |
| 749 | return -ENODEV; |
| 750 | |
Thierry Reding | 84dbf80 | 2013-01-21 11:09:03 +0100 | [diff] [blame] | 751 | dev->base = devm_ioremap_resource(&pdev->dev, mem); |
| 752 | if (IS_ERR(dev->base)) |
| 753 | return PTR_ERR(dev->base); |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 754 | |
| 755 | dev->irq = platform_get_irq(pdev, 0); |
| 756 | if (dev->irq < 0) |
| 757 | return dev->irq; |
| 758 | |
| 759 | rc = devm_request_irq(&pdev->dev, dev->irq, atmel_twi_interrupt, 0, |
| 760 | dev_name(dev->dev), dev); |
| 761 | if (rc) { |
| 762 | dev_err(dev->dev, "Cannot get irq %d: %d\n", dev->irq, rc); |
| 763 | return rc; |
| 764 | } |
| 765 | |
| 766 | platform_set_drvdata(pdev, dev); |
| 767 | |
| 768 | dev->clk = devm_clk_get(dev->dev, NULL); |
| 769 | if (IS_ERR(dev->clk)) { |
| 770 | dev_err(dev->dev, "no clock defined\n"); |
| 771 | return -ENODEV; |
| 772 | } |
| 773 | clk_prepare_enable(dev->clk); |
| 774 | |
Ludovic Desroches | 60937b2 | 2012-11-23 10:09:04 +0100 | [diff] [blame] | 775 | if (dev->pdata->has_dma_support) { |
| 776 | if (at91_twi_configure_dma(dev, phy_addr) == 0) |
| 777 | dev->use_dma = true; |
| 778 | } |
| 779 | |
Marek Roszko | 75b6c4b | 2014-03-11 00:25:38 -0400 | [diff] [blame] | 780 | rc = of_property_read_u32(dev->dev->of_node, "clock-frequency", |
| 781 | &bus_clk_rate); |
| 782 | if (rc) |
| 783 | bus_clk_rate = DEFAULT_TWI_CLK_HZ; |
| 784 | |
| 785 | at91_calc_twi_clock(dev, bus_clk_rate); |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 786 | at91_init_twi_bus(dev); |
| 787 | |
| 788 | snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); |
| 789 | i2c_set_adapdata(&dev->adapter, dev); |
| 790 | dev->adapter.owner = THIS_MODULE; |
Wolfram Sang | b850579 | 2014-07-10 13:46:22 +0200 | [diff] [blame] | 791 | dev->adapter.class = I2C_CLASS_DEPRECATED; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 792 | dev->adapter.algo = &at91_twi_algorithm; |
| 793 | dev->adapter.dev.parent = dev->dev; |
| 794 | dev->adapter.nr = pdev->id; |
| 795 | dev->adapter.timeout = AT91_I2C_TIMEOUT; |
Ludovic Desroches | 70d46a2 | 2012-09-12 08:42:14 +0200 | [diff] [blame] | 796 | dev->adapter.dev.of_node = pdev->dev.of_node; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 797 | |
| 798 | rc = i2c_add_numbered_adapter(&dev->adapter); |
| 799 | if (rc) { |
| 800 | dev_err(dev->dev, "Adapter %s registration failed\n", |
| 801 | dev->adapter.name); |
| 802 | clk_disable_unprepare(dev->clk); |
| 803 | return rc; |
| 804 | } |
| 805 | |
| 806 | dev_info(dev->dev, "AT91 i2c bus driver.\n"); |
| 807 | return 0; |
| 808 | } |
| 809 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 810 | static int at91_twi_remove(struct platform_device *pdev) |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 811 | { |
| 812 | struct at91_twi_dev *dev = platform_get_drvdata(pdev); |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 813 | |
Lars-Peter Clausen | bf51a8c | 2013-03-09 08:16:46 +0000 | [diff] [blame] | 814 | i2c_del_adapter(&dev->adapter); |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 815 | clk_disable_unprepare(dev->clk); |
| 816 | |
Lars-Peter Clausen | bf51a8c | 2013-03-09 08:16:46 +0000 | [diff] [blame] | 817 | return 0; |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 818 | } |
| 819 | |
| 820 | #ifdef CONFIG_PM |
| 821 | |
| 822 | static int at91_twi_runtime_suspend(struct device *dev) |
| 823 | { |
| 824 | struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); |
| 825 | |
| 826 | clk_disable(twi_dev->clk); |
| 827 | |
| 828 | return 0; |
| 829 | } |
| 830 | |
| 831 | static int at91_twi_runtime_resume(struct device *dev) |
| 832 | { |
| 833 | struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); |
| 834 | |
| 835 | return clk_enable(twi_dev->clk); |
| 836 | } |
| 837 | |
| 838 | static const struct dev_pm_ops at91_twi_pm = { |
| 839 | .runtime_suspend = at91_twi_runtime_suspend, |
| 840 | .runtime_resume = at91_twi_runtime_resume, |
| 841 | }; |
| 842 | |
| 843 | #define at91_twi_pm_ops (&at91_twi_pm) |
| 844 | #else |
| 845 | #define at91_twi_pm_ops NULL |
| 846 | #endif |
| 847 | |
| 848 | static struct platform_driver at91_twi_driver = { |
| 849 | .probe = at91_twi_probe, |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 850 | .remove = at91_twi_remove, |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 851 | .id_table = at91_twi_devtypes, |
| 852 | .driver = { |
| 853 | .name = "at91_i2c", |
| 854 | .owner = THIS_MODULE, |
Sachin Kamat | 600abea | 2013-03-14 00:13:03 +0000 | [diff] [blame] | 855 | .of_match_table = of_match_ptr(atmel_twi_dt_ids), |
Nikolaus Voss | fac368a | 2011-11-08 11:49:46 +0100 | [diff] [blame] | 856 | .pm = at91_twi_pm_ops, |
| 857 | }, |
| 858 | }; |
| 859 | |
| 860 | static int __init at91_twi_init(void) |
| 861 | { |
| 862 | return platform_driver_register(&at91_twi_driver); |
| 863 | } |
| 864 | |
| 865 | static void __exit at91_twi_exit(void) |
| 866 | { |
| 867 | platform_driver_unregister(&at91_twi_driver); |
| 868 | } |
| 869 | |
| 870 | subsys_initcall(at91_twi_init); |
| 871 | module_exit(at91_twi_exit); |
| 872 | |
| 873 | MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>"); |
| 874 | MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); |
| 875 | MODULE_LICENSE("GPL"); |
| 876 | MODULE_ALIAS("platform:at91_i2c"); |