1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2002 Motorola GSG-China
4 *
5 * Author:
6 * Darius Augulis, Teltonika Inc.
7 *
8 * Desc.:
9 * Implementation of I2C Adapter/Algorithm Driver
10 * for I2C Bus integrated in Freescale i.MX/MXC processors
11 *
12 * Derived from Motorola GSG China I2C example driver
13 *
14 * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
15 * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
16 * Copyright (C) 2007 RightHand Technologies, Inc.
17 * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
18 *
19 * Copyright 2013 Freescale Semiconductor, Inc.
20 * Copyright 2020 NXP
21 *
22 */
23
24 #include <linux/acpi.h>
25 #include <linux/clk.h>
26 #include <linux/completion.h>
27 #include <linux/delay.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/dmaengine.h>
30 #include <linux/dmapool.h>
31 #include <linux/err.h>
32 #include <linux/errno.h>
33 #include <linux/gpio/consumer.h>
34 #include <linux/i2c.h>
35 #include <linux/init.h>
36 #include <linux/interrupt.h>
37 #include <linux/io.h>
38 #include <linux/iopoll.h>
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/of.h>
42 #include <linux/of_device.h>
43 #include <linux/of_dma.h>
44 #include <linux/pinctrl/consumer.h>
45 #include <linux/platform_data/i2c-imx.h>
46 #include <linux/platform_device.h>
47 #include <linux/pm_runtime.h>
48 #include <linux/sched.h>
49 #include <linux/slab.h>
50
51 /* This will be the driver name the kernel reports */
52 #define DRIVER_NAME "imx-i2c"
53
54 /*
55 * Enable DMA if transfer byte size is bigger than this threshold.
56 * As the hardware request, it must bigger than 4 bytes.\
57 * I have set '16' here, maybe it's not the best but I think it's
58 * the appropriate.
59 */
60 #define DMA_THRESHOLD 16
61 #define DMA_TIMEOUT 1000
62
63 /* IMX I2C registers:
64 * the I2C register offset is different between SoCs,
65 * to provid support for all these chips, split the
66 * register offset into a fixed base address and a
67 * variable shift value, then the full register offset
68 * will be calculated by
69 * reg_off = ( reg_base_addr << reg_shift)
70 */
71 #define IMX_I2C_IADR 0x00 /* i2c slave address */
72 #define IMX_I2C_IFDR 0x01 /* i2c frequency divider */
73 #define IMX_I2C_I2CR 0x02 /* i2c control */
74 #define IMX_I2C_I2SR 0x03 /* i2c status */
75 #define IMX_I2C_I2DR 0x04 /* i2c transfer data */
76
77 /*
78 * All of the layerscape series SoCs support IBIC register.
79 */
80 #define IMX_I2C_IBIC 0x05 /* i2c bus interrupt config */
81
82 #define IMX_I2C_REGSHIFT 2
83 #define VF610_I2C_REGSHIFT 0
84
85 /* Bits of IMX I2C registers */
86 #define I2SR_RXAK 0x01
87 #define I2SR_IIF 0x02
88 #define I2SR_SRW 0x04
89 #define I2SR_IAL 0x10
90 #define I2SR_IBB 0x20
91 #define I2SR_IAAS 0x40
92 #define I2SR_ICF 0x80
93 #define I2CR_DMAEN 0x02
94 #define I2CR_RSTA 0x04
95 #define I2CR_TXAK 0x08
96 #define I2CR_MTX 0x10
97 #define I2CR_MSTA 0x20
98 #define I2CR_IIEN 0x40
99 #define I2CR_IEN 0x80
100 #define IBIC_BIIE 0x80 /* Bus idle interrupt enable */
101
102 /* register bits different operating codes definition:
103 * 1) I2SR: Interrupt flags clear operation differ between SoCs:
104 * - write zero to clear(w0c) INT flag on i.MX,
105 * - but write one to clear(w1c) INT flag on Vybrid.
106 * 2) I2CR: I2C module enable operation also differ between SoCs:
107 * - set I2CR_IEN bit enable the module on i.MX,
108 * - but clear I2CR_IEN bit enable the module on Vybrid.
109 */
110 #define I2SR_CLR_OPCODE_W0C 0x0
111 #define I2SR_CLR_OPCODE_W1C (I2SR_IAL | I2SR_IIF)
112 #define I2CR_IEN_OPCODE_0 0x0
113 #define I2CR_IEN_OPCODE_1 I2CR_IEN
114
115 #define I2C_PM_TIMEOUT 10 /* ms */
116
117 /*
118 * sorted list of clock divider, register value pairs
119 * taken from table 26-5, p.26-9, Freescale i.MX
120 * Integrated Portable System Processor Reference Manual
121 * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
122 *
123 * Duplicated divider values removed from list
124 */
125 struct imx_i2c_clk_pair {
126 u16 div;
127 u16 val;
128 };
129
130 static struct imx_i2c_clk_pair imx_i2c_clk_div[] = {
131 { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
132 { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
133 { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
134 { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
135 { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
136 { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
137 { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
138 { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
139 { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
140 { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
141 { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
142 { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
143 { 3072, 0x1E }, { 3840, 0x1F }
144 };
145
146 /* Vybrid VF610 clock divider, register value pairs */
147 static struct imx_i2c_clk_pair vf610_i2c_clk_div[] = {
148 { 20, 0x00 }, { 22, 0x01 }, { 24, 0x02 }, { 26, 0x03 },
149 { 28, 0x04 }, { 30, 0x05 }, { 32, 0x09 }, { 34, 0x06 },
150 { 36, 0x0A }, { 40, 0x07 }, { 44, 0x0C }, { 48, 0x0D },
151 { 52, 0x43 }, { 56, 0x0E }, { 60, 0x45 }, { 64, 0x12 },
152 { 68, 0x0F }, { 72, 0x13 }, { 80, 0x14 }, { 88, 0x15 },
153 { 96, 0x19 }, { 104, 0x16 }, { 112, 0x1A }, { 128, 0x17 },
154 { 136, 0x4F }, { 144, 0x1C }, { 160, 0x1D }, { 176, 0x55 },
155 { 192, 0x1E }, { 208, 0x56 }, { 224, 0x22 }, { 228, 0x24 },
156 { 240, 0x1F }, { 256, 0x23 }, { 288, 0x5C }, { 320, 0x25 },
157 { 384, 0x26 }, { 448, 0x2A }, { 480, 0x27 }, { 512, 0x2B },
158 { 576, 0x2C }, { 640, 0x2D }, { 768, 0x31 }, { 896, 0x32 },
159 { 960, 0x2F }, { 1024, 0x33 }, { 1152, 0x34 }, { 1280, 0x35 },
160 { 1536, 0x36 }, { 1792, 0x3A }, { 1920, 0x37 }, { 2048, 0x3B },
161 { 2304, 0x3C }, { 2560, 0x3D }, { 3072, 0x3E }, { 3584, 0x7A },
162 { 3840, 0x3F }, { 4096, 0x7B }, { 5120, 0x7D }, { 6144, 0x7E },
163 };
164
165 enum imx_i2c_type {
166 IMX1_I2C,
167 IMX21_I2C,
168 VF610_I2C,
169 };
170
171 struct imx_i2c_hwdata {
172 enum imx_i2c_type devtype;
173 unsigned int regshift;
174 struct imx_i2c_clk_pair *clk_div;
175 unsigned int ndivs;
176 unsigned int i2sr_clr_opcode;
177 unsigned int i2cr_ien_opcode;
178 };
179
180 struct imx_i2c_dma {
181 struct dma_chan *chan_tx;
182 struct dma_chan *chan_rx;
183 struct dma_chan *chan_using;
184 struct completion cmd_complete;
185 dma_addr_t dma_buf;
186 unsigned int dma_len;
187 enum dma_transfer_direction dma_transfer_dir;
188 enum dma_data_direction dma_data_dir;
189 };
190
191 struct imx_i2c_struct {
192 struct i2c_adapter adapter;
193 struct clk *clk;
194 struct notifier_block clk_change_nb;
195 void __iomem *base;
196 wait_queue_head_t queue;
197 unsigned long i2csr;
198 unsigned int disable_delay;
199 int stopped;
200 unsigned int ifdr; /* IMX_I2C_IFDR */
201 unsigned int cur_clk;
202 unsigned int bitrate;
203 const struct imx_i2c_hwdata *hwdata;
204 struct i2c_bus_recovery_info rinfo;
205
206 struct pinctrl *pinctrl;
207 struct pinctrl_state *pinctrl_pins_default;
208 struct pinctrl_state *pinctrl_pins_gpio;
209
210 struct imx_i2c_dma *dma;
211 struct i2c_client *slave;
212 enum i2c_slave_event last_slave_event;
213 };
214
215 static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
216 .devtype = IMX1_I2C,
217 .regshift = IMX_I2C_REGSHIFT,
218 .clk_div = imx_i2c_clk_div,
219 .ndivs = ARRAY_SIZE(imx_i2c_clk_div),
220 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
221 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
222
223 };
224
225 static const struct imx_i2c_hwdata imx21_i2c_hwdata = {
226 .devtype = IMX21_I2C,
227 .regshift = IMX_I2C_REGSHIFT,
228 .clk_div = imx_i2c_clk_div,
229 .ndivs = ARRAY_SIZE(imx_i2c_clk_div),
230 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
231 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
232
233 };
234
235 static struct imx_i2c_hwdata vf610_i2c_hwdata = {
236 .devtype = VF610_I2C,
237 .regshift = VF610_I2C_REGSHIFT,
238 .clk_div = vf610_i2c_clk_div,
239 .ndivs = ARRAY_SIZE(vf610_i2c_clk_div),
240 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W1C,
241 .i2cr_ien_opcode = I2CR_IEN_OPCODE_0,
242
243 };
244
245 static const struct platform_device_id imx_i2c_devtype[] = {
246 {
247 .name = "imx1-i2c",
248 .driver_data = (kernel_ulong_t)&imx1_i2c_hwdata,
249 }, {
250 .name = "imx21-i2c",
251 .driver_data = (kernel_ulong_t)&imx21_i2c_hwdata,
252 }, {
253 /* sentinel */
254 }
255 };
256 MODULE_DEVICE_TABLE(platform, imx_i2c_devtype);
257
258 static const struct of_device_id i2c_imx_dt_ids[] = {
259 { .compatible = "fsl,imx1-i2c", .data = &imx1_i2c_hwdata, },
260 { .compatible = "fsl,imx21-i2c", .data = &imx21_i2c_hwdata, },
261 { .compatible = "fsl,vf610-i2c", .data = &vf610_i2c_hwdata, },
262 { /* sentinel */ }
263 };
264 MODULE_DEVICE_TABLE(of, i2c_imx_dt_ids);
265
266 static const struct acpi_device_id i2c_imx_acpi_ids[] = {
267 {"NXP0001", .driver_data = (kernel_ulong_t)&vf610_i2c_hwdata},
268 { }
269 };
270 MODULE_DEVICE_TABLE(acpi, i2c_imx_acpi_ids);
271
is_imx1_i2c(struct imx_i2c_struct * i2c_imx)272 static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx)
273 {
274 return i2c_imx->hwdata->devtype == IMX1_I2C;
275 }
276
is_vf610_i2c(struct imx_i2c_struct * i2c_imx)277 static inline int is_vf610_i2c(struct imx_i2c_struct *i2c_imx)
278 {
279 return i2c_imx->hwdata->devtype == VF610_I2C;
280 }
281
imx_i2c_write_reg(unsigned int val,struct imx_i2c_struct * i2c_imx,unsigned int reg)282 static inline void imx_i2c_write_reg(unsigned int val,
283 struct imx_i2c_struct *i2c_imx, unsigned int reg)
284 {
285 writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
286 }
287
imx_i2c_read_reg(struct imx_i2c_struct * i2c_imx,unsigned int reg)288 static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
289 unsigned int reg)
290 {
291 return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
292 }
293
i2c_imx_clear_irq(struct imx_i2c_struct * i2c_imx,unsigned int bits)294 static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits)
295 {
296 unsigned int temp;
297
298 /*
299 * i2sr_clr_opcode is the value to clear all interrupts. Here we want to
300 * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits>
301 * toggled. This is required because i.MX needs W0C and Vybrid uses W1C.
302 */
303 temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits;
304 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
305 }
306
307 /* Set up i2c controller register and i2c status register to default value. */
i2c_imx_reset_regs(struct imx_i2c_struct * i2c_imx)308 static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx)
309 {
310 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
311 i2c_imx, IMX_I2C_I2CR);
312 i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL);
313 }
314
315 /* Functions for DMA support */
i2c_imx_dma_request(struct imx_i2c_struct * i2c_imx,dma_addr_t phy_addr)316 static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
317 dma_addr_t phy_addr)
318 {
319 struct imx_i2c_dma *dma;
320 struct dma_slave_config dma_sconfig;
321 struct device *dev = &i2c_imx->adapter.dev;
322 int ret;
323
324 dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
325 if (!dma)
326 return;
327
328 dma->chan_tx = dma_request_chan(dev, "tx");
329 if (IS_ERR(dma->chan_tx)) {
330 ret = PTR_ERR(dma->chan_tx);
331 if (ret != -ENODEV && ret != -EPROBE_DEFER)
332 dev_err(dev, "can't request DMA tx channel (%d)\n", ret);
333 goto fail_al;
334 }
335
336 dma_sconfig.dst_addr = phy_addr +
337 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
338 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
339 dma_sconfig.dst_maxburst = 1;
340 dma_sconfig.direction = DMA_MEM_TO_DEV;
341 ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
342 if (ret < 0) {
343 dev_err(dev, "can't configure tx channel (%d)\n", ret);
344 goto fail_tx;
345 }
346
347 dma->chan_rx = dma_request_chan(dev, "rx");
348 if (IS_ERR(dma->chan_rx)) {
349 ret = PTR_ERR(dma->chan_rx);
350 if (ret != -ENODEV && ret != -EPROBE_DEFER)
351 dev_err(dev, "can't request DMA rx channel (%d)\n", ret);
352 goto fail_tx;
353 }
354
355 dma_sconfig.src_addr = phy_addr +
356 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
357 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
358 dma_sconfig.src_maxburst = 1;
359 dma_sconfig.direction = DMA_DEV_TO_MEM;
360 ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
361 if (ret < 0) {
362 dev_err(dev, "can't configure rx channel (%d)\n", ret);
363 goto fail_rx;
364 }
365
366 i2c_imx->dma = dma;
367 init_completion(&dma->cmd_complete);
368 dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
369 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
370
371 return;
372
373 fail_rx:
374 dma_release_channel(dma->chan_rx);
375 fail_tx:
376 dma_release_channel(dma->chan_tx);
377 fail_al:
378 devm_kfree(dev, dma);
379 }
380
i2c_imx_dma_callback(void * arg)381 static void i2c_imx_dma_callback(void *arg)
382 {
383 struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg;
384 struct imx_i2c_dma *dma = i2c_imx->dma;
385
386 dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
387 dma->dma_len, dma->dma_data_dir);
388 complete(&dma->cmd_complete);
389 }
390
i2c_imx_dma_xfer(struct imx_i2c_struct * i2c_imx,struct i2c_msg * msgs)391 static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
392 struct i2c_msg *msgs)
393 {
394 struct imx_i2c_dma *dma = i2c_imx->dma;
395 struct dma_async_tx_descriptor *txdesc;
396 struct device *dev = &i2c_imx->adapter.dev;
397 struct device *chan_dev = dma->chan_using->device->dev;
398
399 dma->dma_buf = dma_map_single(chan_dev, msgs->buf,
400 dma->dma_len, dma->dma_data_dir);
401 if (dma_mapping_error(chan_dev, dma->dma_buf)) {
402 dev_err(dev, "DMA mapping failed\n");
403 goto err_map;
404 }
405
406 txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
407 dma->dma_len, dma->dma_transfer_dir,
408 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
409 if (!txdesc) {
410 dev_err(dev, "Not able to get desc for DMA xfer\n");
411 goto err_desc;
412 }
413
414 reinit_completion(&dma->cmd_complete);
415 txdesc->callback = i2c_imx_dma_callback;
416 txdesc->callback_param = i2c_imx;
417 if (dma_submit_error(dmaengine_submit(txdesc))) {
418 dev_err(dev, "DMA submit failed\n");
419 goto err_submit;
420 }
421
422 dma_async_issue_pending(dma->chan_using);
423 return 0;
424
425 err_submit:
426 dmaengine_terminate_sync(dma->chan_using);
427 err_desc:
428 dma_unmap_single(chan_dev, dma->dma_buf,
429 dma->dma_len, dma->dma_data_dir);
430 err_map:
431 return -EINVAL;
432 }
433
i2c_imx_dma_free(struct imx_i2c_struct * i2c_imx)434 static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
435 {
436 struct imx_i2c_dma *dma = i2c_imx->dma;
437
438 dma->dma_buf = 0;
439 dma->dma_len = 0;
440
441 dma_release_channel(dma->chan_tx);
442 dma->chan_tx = NULL;
443
444 dma_release_channel(dma->chan_rx);
445 dma->chan_rx = NULL;
446
447 dma->chan_using = NULL;
448 }
449
i2c_imx_bus_busy(struct imx_i2c_struct * i2c_imx,int for_busy,bool atomic)450 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
451 {
452 unsigned long orig_jiffies = jiffies;
453 unsigned int temp;
454
455 while (1) {
456 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
457
458 /* check for arbitration lost */
459 if (temp & I2SR_IAL) {
460 i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
461 return -EAGAIN;
462 }
463
464 if (for_busy && (temp & I2SR_IBB)) {
465 i2c_imx->stopped = 0;
466 break;
467 }
468 if (!for_busy && !(temp & I2SR_IBB)) {
469 i2c_imx->stopped = 1;
470 break;
471 }
472 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
473 dev_dbg(&i2c_imx->adapter.dev,
474 "<%s> I2C bus is busy\n", __func__);
475 return -ETIMEDOUT;
476 }
477 if (atomic)
478 udelay(100);
479 else
480 schedule();
481 }
482
483 return 0;
484 }
485
i2c_imx_trx_complete(struct imx_i2c_struct * i2c_imx,bool atomic)486 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic)
487 {
488 if (atomic) {
489 void __iomem *addr = i2c_imx->base + (IMX_I2C_I2SR << i2c_imx->hwdata->regshift);
490 unsigned int regval;
491
492 /*
493 * The formula for the poll timeout is documented in the RM
494 * Rev.5 on page 1878:
495 * T_min = 10/F_scl
496 * Set the value hard as it is done for the non-atomic use-case.
497 * Use 10 kHz for the calculation since this is the minimum
498 * allowed SMBus frequency. Also add an offset of 100us since it
499 * turned out that the I2SR_IIF bit isn't set correctly within
500 * the minimum timeout in polling mode.
501 */
502 readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100);
503 i2c_imx->i2csr = regval;
504 i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL);
505 } else {
506 wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
507 }
508
509 if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
510 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
511 return -ETIMEDOUT;
512 }
513
514 /* check for arbitration lost */
515 if (i2c_imx->i2csr & I2SR_IAL) {
516 dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__);
517 i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
518
519 i2c_imx->i2csr = 0;
520 return -EAGAIN;
521 }
522
523 dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
524 i2c_imx->i2csr = 0;
525 return 0;
526 }
527
i2c_imx_acked(struct imx_i2c_struct * i2c_imx)528 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
529 {
530 if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) {
531 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
532 return -ENXIO; /* No ACK */
533 }
534
535 dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
536 return 0;
537 }
538
i2c_imx_set_clk(struct imx_i2c_struct * i2c_imx,unsigned int i2c_clk_rate)539 static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
540 unsigned int i2c_clk_rate)
541 {
542 struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
543 unsigned int div;
544 int i;
545
546 /* Divider value calculation */
547 if (i2c_imx->cur_clk == i2c_clk_rate)
548 return;
549
550 i2c_imx->cur_clk = i2c_clk_rate;
551
552 div = DIV_ROUND_UP(i2c_clk_rate, i2c_imx->bitrate);
553 if (div < i2c_clk_div[0].div)
554 i = 0;
555 else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div)
556 i = i2c_imx->hwdata->ndivs - 1;
557 else
558 for (i = 0; i2c_clk_div[i].div < div; i++)
559 ;
560
561 /* Store divider value */
562 i2c_imx->ifdr = i2c_clk_div[i].val;
563
564 /*
565 * There dummy delay is calculated.
566 * It should be about one I2C clock period long.
567 * This delay is used in I2C bus disable function
568 * to fix chip hardware bug.
569 */
570 i2c_imx->disable_delay = DIV_ROUND_UP(500000U * i2c_clk_div[i].div,
571 i2c_clk_rate / 2);
572
573 #ifdef CONFIG_I2C_DEBUG_BUS
574 dev_dbg(&i2c_imx->adapter.dev, "I2C_CLK=%d, REQ DIV=%d\n",
575 i2c_clk_rate, div);
576 dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n",
577 i2c_clk_div[i].val, i2c_clk_div[i].div);
578 #endif
579 }
580
i2c_imx_clk_notifier_call(struct notifier_block * nb,unsigned long action,void * data)581 static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
582 unsigned long action, void *data)
583 {
584 struct clk_notifier_data *ndata = data;
585 struct imx_i2c_struct *i2c_imx = container_of(nb,
586 struct imx_i2c_struct,
587 clk_change_nb);
588
589 if (action & POST_RATE_CHANGE)
590 i2c_imx_set_clk(i2c_imx, ndata->new_rate);
591
592 return NOTIFY_OK;
593 }
594
i2c_imx_start(struct imx_i2c_struct * i2c_imx,bool atomic)595 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
596 {
597 unsigned int temp = 0;
598 int result;
599
600 imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
601 /* Enable I2C controller */
602 imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
603 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
604
605 /* Wait controller to be stable */
606 if (atomic)
607 udelay(50);
608 else
609 usleep_range(50, 150);
610
611 /* Start I2C transaction */
612 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
613 temp |= I2CR_MSTA;
614 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
615 result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
616 if (result)
617 return result;
618
619 temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
620 if (atomic)
621 temp &= ~I2CR_IIEN; /* Disable interrupt */
622
623 temp &= ~I2CR_DMAEN;
624 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
625 return result;
626 }
627
i2c_imx_stop(struct imx_i2c_struct * i2c_imx,bool atomic)628 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic)
629 {
630 unsigned int temp = 0;
631
632 if (!i2c_imx->stopped) {
633 /* Stop I2C transaction */
634 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
635 if (!(temp & I2CR_MSTA))
636 i2c_imx->stopped = 1;
637 temp &= ~(I2CR_MSTA | I2CR_MTX);
638 if (i2c_imx->dma)
639 temp &= ~I2CR_DMAEN;
640 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
641 }
642 if (is_imx1_i2c(i2c_imx)) {
643 /*
644 * This delay caused by an i.MXL hardware bug.
645 * If no (or too short) delay, no "STOP" bit will be generated.
646 */
647 udelay(i2c_imx->disable_delay);
648 }
649
650 if (!i2c_imx->stopped)
651 i2c_imx_bus_busy(i2c_imx, 0, atomic);
652
653 /* Disable I2C controller */
654 temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
655 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
656 }
657
658 /*
659 * Enable bus idle interrupts
660 * Note: IBIC register will be cleared after disabled i2c module.
661 * All of layerscape series SoCs support IBIC register.
662 */
i2c_imx_enable_bus_idle(struct imx_i2c_struct * i2c_imx)663 static void i2c_imx_enable_bus_idle(struct imx_i2c_struct *i2c_imx)
664 {
665 if (is_vf610_i2c(i2c_imx)) {
666 unsigned int temp;
667
668 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_IBIC);
669 temp |= IBIC_BIIE;
670 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_IBIC);
671 }
672 }
673
i2c_imx_slave_event(struct imx_i2c_struct * i2c_imx,enum i2c_slave_event event,u8 * val)674 static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx,
675 enum i2c_slave_event event, u8 *val)
676 {
677 i2c_slave_event(i2c_imx->slave, event, val);
678 i2c_imx->last_slave_event = event;
679 }
680
i2c_imx_slave_finish_op(struct imx_i2c_struct * i2c_imx)681 static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx)
682 {
683 u8 val;
684
685 while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) {
686 switch (i2c_imx->last_slave_event) {
687 case I2C_SLAVE_READ_REQUESTED:
688 i2c_imx_slave_event(i2c_imx, I2C_SLAVE_READ_PROCESSED,
689 &val);
690 break;
691
692 case I2C_SLAVE_WRITE_REQUESTED:
693 case I2C_SLAVE_READ_PROCESSED:
694 case I2C_SLAVE_WRITE_RECEIVED:
695 i2c_imx_slave_event(i2c_imx, I2C_SLAVE_STOP, &val);
696 break;
697
698 case I2C_SLAVE_STOP:
699 break;
700 }
701 }
702 }
703
i2c_imx_slave_isr(struct imx_i2c_struct * i2c_imx,unsigned int status,unsigned int ctl)704 static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx,
705 unsigned int status, unsigned int ctl)
706 {
707 u8 value;
708
709 if (status & I2SR_IAL) { /* Arbitration lost */
710 i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
711 if (!(status & I2SR_IAAS))
712 return IRQ_HANDLED;
713 }
714
715 if (status & I2SR_IAAS) { /* Addressed as a slave */
716 i2c_imx_slave_finish_op(i2c_imx);
717 if (status & I2SR_SRW) { /* Master wants to read from us*/
718 dev_dbg(&i2c_imx->adapter.dev, "read requested");
719 i2c_imx_slave_event(i2c_imx,
720 I2C_SLAVE_READ_REQUESTED, &value);
721
722 /* Slave transmit */
723 ctl |= I2CR_MTX;
724 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
725
726 /* Send data */
727 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR);
728 } else { /* Master wants to write to us */
729 dev_dbg(&i2c_imx->adapter.dev, "write requested");
730 i2c_imx_slave_event(i2c_imx,
731 I2C_SLAVE_WRITE_REQUESTED, &value);
732
733 /* Slave receive */
734 ctl &= ~I2CR_MTX;
735 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
736 /* Dummy read */
737 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
738 }
739 } else if (!(ctl & I2CR_MTX)) { /* Receive mode */
740 if (status & I2SR_IBB) { /* No STOP signal detected */
741 value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
742 i2c_imx_slave_event(i2c_imx,
743 I2C_SLAVE_WRITE_RECEIVED, &value);
744 } else { /* STOP signal is detected */
745 dev_dbg(&i2c_imx->adapter.dev,
746 "STOP signal detected");
747 i2c_imx_slave_event(i2c_imx,
748 I2C_SLAVE_STOP, &value);
749 }
750 } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */
751 ctl |= I2CR_MTX;
752 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
753
754 i2c_imx_slave_event(i2c_imx,
755 I2C_SLAVE_READ_PROCESSED, &value);
756
757 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR);
758 } else { /* Transmit mode received NAK */
759 ctl &= ~I2CR_MTX;
760 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
761 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
762 }
763
764 return IRQ_HANDLED;
765 }
766
i2c_imx_slave_init(struct imx_i2c_struct * i2c_imx)767 static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx)
768 {
769 int temp;
770
771 /* Set slave addr. */
772 imx_i2c_write_reg((i2c_imx->slave->addr << 1), i2c_imx, IMX_I2C_IADR);
773
774 i2c_imx_reset_regs(i2c_imx);
775
776 /* Enable module */
777 temp = i2c_imx->hwdata->i2cr_ien_opcode;
778 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
779
780 /* Enable interrupt from i2c module */
781 temp |= I2CR_IIEN;
782 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
783
784 i2c_imx_enable_bus_idle(i2c_imx);
785 }
786
i2c_imx_reg_slave(struct i2c_client * client)787 static int i2c_imx_reg_slave(struct i2c_client *client)
788 {
789 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
790 int ret;
791
792 if (i2c_imx->slave)
793 return -EBUSY;
794
795 i2c_imx->slave = client;
796 i2c_imx->last_slave_event = I2C_SLAVE_STOP;
797
798 /* Resume */
799 ret = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
800 if (ret < 0) {
801 dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller");
802 return ret;
803 }
804
805 i2c_imx_slave_init(i2c_imx);
806
807 return 0;
808 }
809
i2c_imx_unreg_slave(struct i2c_client * client)810 static int i2c_imx_unreg_slave(struct i2c_client *client)
811 {
812 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
813 int ret;
814
815 if (!i2c_imx->slave)
816 return -EINVAL;
817
818 /* Reset slave address. */
819 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
820
821 i2c_imx_reset_regs(i2c_imx);
822
823 i2c_imx->slave = NULL;
824
825 /* Suspend */
826 ret = pm_runtime_put_sync(i2c_imx->adapter.dev.parent);
827 if (ret < 0)
828 dev_err(&i2c_imx->adapter.dev, "failed to suspend i2c controller");
829
830 return ret;
831 }
832
i2c_imx_master_isr(struct imx_i2c_struct * i2c_imx,unsigned int status)833 static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx, unsigned int status)
834 {
835 /* save status register */
836 i2c_imx->i2csr = status;
837 wake_up(&i2c_imx->queue);
838
839 return IRQ_HANDLED;
840 }
841
i2c_imx_isr(int irq,void * dev_id)842 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
843 {
844 struct imx_i2c_struct *i2c_imx = dev_id;
845 unsigned int ctl, status;
846
847 status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
848 ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
849
850 if (status & I2SR_IIF) {
851 i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
852 if (i2c_imx->slave) {
853 if (!(ctl & I2CR_MSTA)) {
854 return i2c_imx_slave_isr(i2c_imx, status, ctl);
855 } else if (i2c_imx->last_slave_event !=
856 I2C_SLAVE_STOP) {
857 i2c_imx_slave_finish_op(i2c_imx);
858 }
859 }
860 return i2c_imx_master_isr(i2c_imx, status);
861 }
862
863 return IRQ_NONE;
864 }
865
i2c_imx_dma_write(struct imx_i2c_struct * i2c_imx,struct i2c_msg * msgs)866 static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
867 struct i2c_msg *msgs)
868 {
869 int result;
870 unsigned long time_left;
871 unsigned int temp = 0;
872 unsigned long orig_jiffies = jiffies;
873 struct imx_i2c_dma *dma = i2c_imx->dma;
874 struct device *dev = &i2c_imx->adapter.dev;
875
876 dma->chan_using = dma->chan_tx;
877 dma->dma_transfer_dir = DMA_MEM_TO_DEV;
878 dma->dma_data_dir = DMA_TO_DEVICE;
879 dma->dma_len = msgs->len - 1;
880 result = i2c_imx_dma_xfer(i2c_imx, msgs);
881 if (result)
882 return result;
883
884 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
885 temp |= I2CR_DMAEN;
886 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
887
888 /*
889 * Write slave address.
890 * The first byte must be transmitted by the CPU.
891 */
892 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
893 time_left = wait_for_completion_timeout(
894 &i2c_imx->dma->cmd_complete,
895 msecs_to_jiffies(DMA_TIMEOUT));
896 if (time_left == 0) {
897 dmaengine_terminate_sync(dma->chan_using);
898 return -ETIMEDOUT;
899 }
900
901 /* Waiting for transfer complete. */
902 while (1) {
903 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
904 if (temp & I2SR_ICF)
905 break;
906 if (time_after(jiffies, orig_jiffies +
907 msecs_to_jiffies(DMA_TIMEOUT))) {
908 dev_dbg(dev, "<%s> Timeout\n", __func__);
909 return -ETIMEDOUT;
910 }
911 schedule();
912 }
913
914 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
915 temp &= ~I2CR_DMAEN;
916 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
917
918 /* The last data byte must be transferred by the CPU. */
919 imx_i2c_write_reg(msgs->buf[msgs->len-1],
920 i2c_imx, IMX_I2C_I2DR);
921 result = i2c_imx_trx_complete(i2c_imx, false);
922 if (result)
923 return result;
924
925 return i2c_imx_acked(i2c_imx);
926 }
927
i2c_imx_dma_read(struct imx_i2c_struct * i2c_imx,struct i2c_msg * msgs,bool is_lastmsg)928 static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
929 struct i2c_msg *msgs, bool is_lastmsg)
930 {
931 int result;
932 unsigned long time_left;
933 unsigned int temp;
934 unsigned long orig_jiffies = jiffies;
935 struct imx_i2c_dma *dma = i2c_imx->dma;
936 struct device *dev = &i2c_imx->adapter.dev;
937
938
939 dma->chan_using = dma->chan_rx;
940 dma->dma_transfer_dir = DMA_DEV_TO_MEM;
941 dma->dma_data_dir = DMA_FROM_DEVICE;
942 /* The last two data bytes must be transferred by the CPU. */
943 dma->dma_len = msgs->len - 2;
944 result = i2c_imx_dma_xfer(i2c_imx, msgs);
945 if (result)
946 return result;
947
948 time_left = wait_for_completion_timeout(
949 &i2c_imx->dma->cmd_complete,
950 msecs_to_jiffies(DMA_TIMEOUT));
951 if (time_left == 0) {
952 dmaengine_terminate_sync(dma->chan_using);
953 return -ETIMEDOUT;
954 }
955
956 /* waiting for transfer complete. */
957 while (1) {
958 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
959 if (temp & I2SR_ICF)
960 break;
961 if (time_after(jiffies, orig_jiffies +
962 msecs_to_jiffies(DMA_TIMEOUT))) {
963 dev_dbg(dev, "<%s> Timeout\n", __func__);
964 return -ETIMEDOUT;
965 }
966 schedule();
967 }
968
969 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
970 temp &= ~I2CR_DMAEN;
971 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
972
973 /* read n-1 byte data */
974 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
975 temp |= I2CR_TXAK;
976 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
977
978 msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
979 /* read n byte data */
980 result = i2c_imx_trx_complete(i2c_imx, false);
981 if (result)
982 return result;
983
984 if (is_lastmsg) {
985 /*
986 * It must generate STOP before read I2DR to prevent
987 * controller from generating another clock cycle
988 */
989 dev_dbg(dev, "<%s> clear MSTA\n", __func__);
990 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
991 if (!(temp & I2CR_MSTA))
992 i2c_imx->stopped = 1;
993 temp &= ~(I2CR_MSTA | I2CR_MTX);
994 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
995 if (!i2c_imx->stopped)
996 i2c_imx_bus_busy(i2c_imx, 0, false);
997 } else {
998 /*
999 * For i2c master receiver repeat restart operation like:
1000 * read -> repeat MSTA -> read/write
1001 * The controller must set MTX before read the last byte in
1002 * the first read operation, otherwise the first read cost
1003 * one extra clock cycle.
1004 */
1005 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
1006 temp |= I2CR_MTX;
1007 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
1008 }
1009 msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
1010
1011 return 0;
1012 }
1013
i2c_imx_write(struct imx_i2c_struct * i2c_imx,struct i2c_msg * msgs,bool atomic)1014 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
1015 bool atomic)
1016 {
1017 int i, result;
1018
1019 dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
1020 __func__, i2c_8bit_addr_from_msg(msgs));
1021
1022 /* write slave address */
1023 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
1024 result = i2c_imx_trx_complete(i2c_imx, atomic);
1025 if (result)
1026 return result;
1027 result = i2c_imx_acked(i2c_imx);
1028 if (result)
1029 return result;
1030 dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
1031
1032 /* write data */
1033 for (i = 0; i < msgs->len; i++) {
1034 dev_dbg(&i2c_imx->adapter.dev,
1035 "<%s> write byte: B%d=0x%X\n",
1036 __func__, i, msgs->buf[i]);
1037 imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
1038 result = i2c_imx_trx_complete(i2c_imx, atomic);
1039 if (result)
1040 return result;
1041 result = i2c_imx_acked(i2c_imx);
1042 if (result)
1043 return result;
1044 }
1045 return 0;
1046 }
1047
i2c_imx_read(struct imx_i2c_struct * i2c_imx,struct i2c_msg * msgs,bool is_lastmsg,bool atomic)1048 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
1049 bool is_lastmsg, bool atomic)
1050 {
1051 int i, result;
1052 unsigned int temp;
1053 int block_data = msgs->flags & I2C_M_RECV_LEN;
1054 int use_dma = i2c_imx->dma && msgs->len >= DMA_THRESHOLD && !block_data;
1055
1056 dev_dbg(&i2c_imx->adapter.dev,
1057 "<%s> write slave address: addr=0x%x\n",
1058 __func__, i2c_8bit_addr_from_msg(msgs));
1059
1060 /* write slave address */
1061 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
1062 result = i2c_imx_trx_complete(i2c_imx, atomic);
1063 if (result)
1064 return result;
1065 result = i2c_imx_acked(i2c_imx);
1066 if (result)
1067 return result;
1068
1069 dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
1070
1071 /* setup bus to read data */
1072 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
1073 temp &= ~I2CR_MTX;
1074
1075 /*
1076 * Reset the I2CR_TXAK flag initially for SMBus block read since the
1077 * length is unknown
1078 */
1079 if ((msgs->len - 1) || block_data)
1080 temp &= ~I2CR_TXAK;
1081 if (use_dma)
1082 temp |= I2CR_DMAEN;
1083 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
1084 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */
1085
1086 dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
1087
1088 if (use_dma)
1089 return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg);
1090
1091 /* read data */
1092 for (i = 0; i < msgs->len; i++) {
1093 u8 len = 0;
1094
1095 result = i2c_imx_trx_complete(i2c_imx, atomic);
1096 if (result)
1097 return result;
1098 /*
1099 * First byte is the length of remaining packet
1100 * in the SMBus block data read. Add it to
1101 * msgs->len.
1102 */
1103 if ((!i) && block_data) {
1104 len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
1105 if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX))
1106 return -EPROTO;
1107 dev_dbg(&i2c_imx->adapter.dev,
1108 "<%s> read length: 0x%X\n",
1109 __func__, len);
1110 msgs->len += len;
1111 }
1112 if (i == (msgs->len - 1)) {
1113 if (is_lastmsg) {
1114 /*
1115 * It must generate STOP before read I2DR to prevent
1116 * controller from generating another clock cycle
1117 */
1118 dev_dbg(&i2c_imx->adapter.dev,
1119 "<%s> clear MSTA\n", __func__);
1120 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
1121 if (!(temp & I2CR_MSTA))
1122 i2c_imx->stopped = 1;
1123 temp &= ~(I2CR_MSTA | I2CR_MTX);
1124 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
1125 if (!i2c_imx->stopped)
1126 i2c_imx_bus_busy(i2c_imx, 0, atomic);
1127 } else {
1128 /*
1129 * For i2c master receiver repeat restart operation like:
1130 * read -> repeat MSTA -> read/write
1131 * The controller must set MTX before read the last byte in
1132 * the first read operation, otherwise the first read cost
1133 * one extra clock cycle.
1134 */
1135 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
1136 temp |= I2CR_MTX;
1137 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
1138 }
1139 } else if (i == (msgs->len - 2)) {
1140 dev_dbg(&i2c_imx->adapter.dev,
1141 "<%s> set TXAK\n", __func__);
1142 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
1143 temp |= I2CR_TXAK;
1144 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
1145 }
1146 if ((!i) && block_data)
1147 msgs->buf[0] = len;
1148 else
1149 msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
1150 dev_dbg(&i2c_imx->adapter.dev,
1151 "<%s> read byte: B%d=0x%X\n",
1152 __func__, i, msgs->buf[i]);
1153 }
1154 return 0;
1155 }
1156
i2c_imx_xfer_common(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num,bool atomic)1157 static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
1158 struct i2c_msg *msgs, int num, bool atomic)
1159 {
1160 unsigned int i, temp;
1161 int result;
1162 bool is_lastmsg = false;
1163 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
1164
1165 /* Start I2C transfer */
1166 result = i2c_imx_start(i2c_imx, atomic);
1167 if (result) {
1168 /*
1169 * Bus recovery uses gpiod_get_value_cansleep() which is not
1170 * allowed within atomic context.
1171 */
1172 if (!atomic && i2c_imx->adapter.bus_recovery_info) {
1173 i2c_recover_bus(&i2c_imx->adapter);
1174 result = i2c_imx_start(i2c_imx, atomic);
1175 }
1176 }
1177
1178 if (result)
1179 goto fail0;
1180
1181 /* read/write data */
1182 for (i = 0; i < num; i++) {
1183 if (i == num - 1)
1184 is_lastmsg = true;
1185
1186 if (i) {
1187 dev_dbg(&i2c_imx->adapter.dev,
1188 "<%s> repeated start\n", __func__);
1189 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
1190 temp |= I2CR_RSTA;
1191 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
1192 result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
1193 if (result)
1194 goto fail0;
1195 }
1196 dev_dbg(&i2c_imx->adapter.dev,
1197 "<%s> transfer message: %d\n", __func__, i);
1198 /* write/read data */
1199 #ifdef CONFIG_I2C_DEBUG_BUS
1200 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
1201 dev_dbg(&i2c_imx->adapter.dev,
1202 "<%s> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
1203 __func__,
1204 (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
1205 (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
1206 (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
1207 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
1208 dev_dbg(&i2c_imx->adapter.dev,
1209 "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
1210 __func__,
1211 (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
1212 (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
1213 (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
1214 (temp & I2SR_RXAK ? 1 : 0));
1215 #endif
1216 if (msgs[i].flags & I2C_M_RD) {
1217 result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, atomic);
1218 } else {
1219 if (!atomic &&
1220 i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD)
1221 result = i2c_imx_dma_write(i2c_imx, &msgs[i]);
1222 else
1223 result = i2c_imx_write(i2c_imx, &msgs[i], atomic);
1224 }
1225 if (result)
1226 goto fail0;
1227 }
1228
1229 fail0:
1230 /* Stop I2C transfer */
1231 i2c_imx_stop(i2c_imx, atomic);
1232
1233 dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
1234 (result < 0) ? "error" : "success msg",
1235 (result < 0) ? result : num);
1236 /* After data is transferred, switch to slave mode(as a receiver) */
1237 if (i2c_imx->slave)
1238 i2c_imx_slave_init(i2c_imx);
1239
1240 return (result < 0) ? result : num;
1241 }
1242
i2c_imx_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)1243 static int i2c_imx_xfer(struct i2c_adapter *adapter,
1244 struct i2c_msg *msgs, int num)
1245 {
1246 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
1247 int result;
1248
1249 result = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
1250 if (result < 0)
1251 return result;
1252
1253 result = i2c_imx_xfer_common(adapter, msgs, num, false);
1254
1255 pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent);
1256 pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent);
1257
1258 return result;
1259 }
1260
i2c_imx_xfer_atomic(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)1261 static int i2c_imx_xfer_atomic(struct i2c_adapter *adapter,
1262 struct i2c_msg *msgs, int num)
1263 {
1264 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
1265 int result;
1266
1267 result = clk_enable(i2c_imx->clk);
1268 if (result)
1269 return result;
1270
1271 result = i2c_imx_xfer_common(adapter, msgs, num, true);
1272
1273 clk_disable(i2c_imx->clk);
1274
1275 return result;
1276 }
1277
i2c_imx_prepare_recovery(struct i2c_adapter * adap)1278 static void i2c_imx_prepare_recovery(struct i2c_adapter *adap)
1279 {
1280 struct imx_i2c_struct *i2c_imx;
1281
1282 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
1283
1284 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio);
1285 }
1286
i2c_imx_unprepare_recovery(struct i2c_adapter * adap)1287 static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap)
1288 {
1289 struct imx_i2c_struct *i2c_imx;
1290
1291 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
1292
1293 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default);
1294 }
1295
1296 /*
1297 * We switch SCL and SDA to their GPIO function and do some bitbanging
1298 * for bus recovery. These alternative pinmux settings can be
1299 * described in the device tree by a separate pinctrl state "gpio". If
1300 * this is missing this is not a big problem, the only implication is
1301 * that we can't do bus recovery.
1302 */
i2c_imx_init_recovery_info(struct imx_i2c_struct * i2c_imx,struct platform_device * pdev)1303 static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
1304 struct platform_device *pdev)
1305 {
1306 struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo;
1307
1308 i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev);
1309 if (!i2c_imx->pinctrl || IS_ERR(i2c_imx->pinctrl)) {
1310 dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n");
1311 return PTR_ERR(i2c_imx->pinctrl);
1312 }
1313
1314 i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl,
1315 PINCTRL_STATE_DEFAULT);
1316 i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl,
1317 "gpio");
1318 rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
1319 rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
1320
1321 if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER ||
1322 PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) {
1323 return -EPROBE_DEFER;
1324 } else if (IS_ERR(rinfo->sda_gpiod) ||
1325 IS_ERR(rinfo->scl_gpiod) ||
1326 IS_ERR(i2c_imx->pinctrl_pins_default) ||
1327 IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
1328 dev_dbg(&pdev->dev, "recovery information incomplete\n");
1329 return 0;
1330 }
1331
1332 dev_dbg(&pdev->dev, "using scl%s for recovery\n",
1333 rinfo->sda_gpiod ? ",sda" : "");
1334
1335 rinfo->prepare_recovery = i2c_imx_prepare_recovery;
1336 rinfo->unprepare_recovery = i2c_imx_unprepare_recovery;
1337 rinfo->recover_bus = i2c_generic_scl_recovery;
1338 i2c_imx->adapter.bus_recovery_info = rinfo;
1339
1340 return 0;
1341 }
1342
i2c_imx_func(struct i2c_adapter * adapter)1343 static u32 i2c_imx_func(struct i2c_adapter *adapter)
1344 {
1345 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
1346 | I2C_FUNC_SMBUS_READ_BLOCK_DATA;
1347 }
1348
1349 static const struct i2c_algorithm i2c_imx_algo = {
1350 .master_xfer = i2c_imx_xfer,
1351 .master_xfer_atomic = i2c_imx_xfer_atomic,
1352 .functionality = i2c_imx_func,
1353 .reg_slave = i2c_imx_reg_slave,
1354 .unreg_slave = i2c_imx_unreg_slave,
1355 };
1356
i2c_imx_probe(struct platform_device * pdev)1357 static int i2c_imx_probe(struct platform_device *pdev)
1358 {
1359 struct imx_i2c_struct *i2c_imx;
1360 struct resource *res;
1361 struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
1362 void __iomem *base;
1363 int irq, ret;
1364 dma_addr_t phy_addr;
1365 const struct imx_i2c_hwdata *match;
1366
1367 irq = platform_get_irq(pdev, 0);
1368 if (irq < 0)
1369 return irq;
1370
1371 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1372 base = devm_ioremap_resource(&pdev->dev, res);
1373 if (IS_ERR(base))
1374 return PTR_ERR(base);
1375
1376 phy_addr = (dma_addr_t)res->start;
1377 i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL);
1378 if (!i2c_imx)
1379 return -ENOMEM;
1380
1381 match = device_get_match_data(&pdev->dev);
1382 if (match)
1383 i2c_imx->hwdata = match;
1384 else
1385 i2c_imx->hwdata = (struct imx_i2c_hwdata *)
1386 platform_get_device_id(pdev)->driver_data;
1387
1388 /* Setup i2c_imx driver structure */
1389 strscpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
1390 i2c_imx->adapter.owner = THIS_MODULE;
1391 i2c_imx->adapter.algo = &i2c_imx_algo;
1392 i2c_imx->adapter.dev.parent = &pdev->dev;
1393 i2c_imx->adapter.nr = pdev->id;
1394 i2c_imx->adapter.dev.of_node = pdev->dev.of_node;
1395 i2c_imx->base = base;
1396 ACPI_COMPANION_SET(&i2c_imx->adapter.dev, ACPI_COMPANION(&pdev->dev));
1397
1398 /* Get I2C clock */
1399 i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
1400 if (IS_ERR(i2c_imx->clk))
1401 return dev_err_probe(&pdev->dev, PTR_ERR(i2c_imx->clk),
1402 "can't get I2C clock\n");
1403
1404 ret = clk_prepare_enable(i2c_imx->clk);
1405 if (ret) {
1406 dev_err(&pdev->dev, "can't enable I2C clock, ret=%d\n", ret);
1407 return ret;
1408 }
1409
1410 /* Init queue */
1411 init_waitqueue_head(&i2c_imx->queue);
1412
1413 /* Set up adapter data */
1414 i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
1415
1416 /* Set up platform driver data */
1417 platform_set_drvdata(pdev, i2c_imx);
1418
1419 pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
1420 pm_runtime_use_autosuspend(&pdev->dev);
1421 pm_runtime_set_active(&pdev->dev);
1422 pm_runtime_enable(&pdev->dev);
1423
1424 ret = pm_runtime_get_sync(&pdev->dev);
1425 if (ret < 0)
1426 goto rpm_disable;
1427
1428 /* Request IRQ */
1429 ret = request_threaded_irq(irq, i2c_imx_isr, NULL, IRQF_SHARED,
1430 pdev->name, i2c_imx);
1431 if (ret) {
1432 dev_err(&pdev->dev, "can't claim irq %d\n", irq);
1433 goto rpm_disable;
1434 }
1435
1436 /* Set up clock divider */
1437 i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
1438 ret = of_property_read_u32(pdev->dev.of_node,
1439 "clock-frequency", &i2c_imx->bitrate);
1440 if (ret < 0 && pdata && pdata->bitrate)
1441 i2c_imx->bitrate = pdata->bitrate;
1442 i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call;
1443 clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb);
1444 i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
1445
1446 i2c_imx_reset_regs(i2c_imx);
1447
1448 /* Init optional bus recovery function */
1449 ret = i2c_imx_init_recovery_info(i2c_imx, pdev);
1450 /* Give it another chance if pinctrl used is not ready yet */
1451 if (ret == -EPROBE_DEFER)
1452 goto clk_notifier_unregister;
1453
1454 /* Add I2C adapter */
1455 ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
1456 if (ret < 0)
1457 goto clk_notifier_unregister;
1458
1459 pm_runtime_mark_last_busy(&pdev->dev);
1460 pm_runtime_put_autosuspend(&pdev->dev);
1461
1462 dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
1463 dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res);
1464 dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
1465 i2c_imx->adapter.name);
1466 dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
1467
1468 /* Init DMA config if supported */
1469 i2c_imx_dma_request(i2c_imx, phy_addr);
1470
1471 return 0; /* Return OK */
1472
1473 clk_notifier_unregister:
1474 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
1475 free_irq(irq, i2c_imx);
1476 rpm_disable:
1477 pm_runtime_put_noidle(&pdev->dev);
1478 pm_runtime_disable(&pdev->dev);
1479 pm_runtime_set_suspended(&pdev->dev);
1480 pm_runtime_dont_use_autosuspend(&pdev->dev);
1481 clk_disable_unprepare(i2c_imx->clk);
1482 return ret;
1483 }
1484
i2c_imx_remove(struct platform_device * pdev)1485 static int i2c_imx_remove(struct platform_device *pdev)
1486 {
1487 struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
1488 int irq, ret;
1489
1490 ret = pm_runtime_resume_and_get(&pdev->dev);
1491 if (ret < 0)
1492 return ret;
1493
1494 /* remove adapter */
1495 dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
1496 i2c_del_adapter(&i2c_imx->adapter);
1497
1498 if (i2c_imx->dma)
1499 i2c_imx_dma_free(i2c_imx);
1500
1501 /* setup chip registers to defaults */
1502 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
1503 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR);
1504 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR);
1505 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
1506
1507 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
1508 irq = platform_get_irq(pdev, 0);
1509 if (irq >= 0)
1510 free_irq(irq, i2c_imx);
1511 clk_disable_unprepare(i2c_imx->clk);
1512
1513 pm_runtime_put_noidle(&pdev->dev);
1514 pm_runtime_disable(&pdev->dev);
1515
1516 return 0;
1517 }
1518
i2c_imx_runtime_suspend(struct device * dev)1519 static int __maybe_unused i2c_imx_runtime_suspend(struct device *dev)
1520 {
1521 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1522
1523 clk_disable(i2c_imx->clk);
1524
1525 return 0;
1526 }
1527
i2c_imx_runtime_resume(struct device * dev)1528 static int __maybe_unused i2c_imx_runtime_resume(struct device *dev)
1529 {
1530 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1531 int ret;
1532
1533 ret = clk_enable(i2c_imx->clk);
1534 if (ret)
1535 dev_err(dev, "can't enable I2C clock, ret=%d\n", ret);
1536
1537 return ret;
1538 }
1539
1540 static const struct dev_pm_ops i2c_imx_pm_ops = {
1541 SET_RUNTIME_PM_OPS(i2c_imx_runtime_suspend,
1542 i2c_imx_runtime_resume, NULL)
1543 };
1544
1545 static struct platform_driver i2c_imx_driver = {
1546 .probe = i2c_imx_probe,
1547 .remove = i2c_imx_remove,
1548 .driver = {
1549 .name = DRIVER_NAME,
1550 .pm = &i2c_imx_pm_ops,
1551 .of_match_table = i2c_imx_dt_ids,
1552 .acpi_match_table = i2c_imx_acpi_ids,
1553 },
1554 .id_table = imx_i2c_devtype,
1555 };
1556
i2c_adap_imx_init(void)1557 static int __init i2c_adap_imx_init(void)
1558 {
1559 return platform_driver_register(&i2c_imx_driver);
1560 }
1561 subsys_initcall(i2c_adap_imx_init);
1562
i2c_adap_imx_exit(void)1563 static void __exit i2c_adap_imx_exit(void)
1564 {
1565 platform_driver_unregister(&i2c_imx_driver);
1566 }
1567 module_exit(i2c_adap_imx_exit);
1568
1569 MODULE_LICENSE("GPL");
1570 MODULE_AUTHOR("Darius Augulis");
1571 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
1572 MODULE_ALIAS("platform:" DRIVER_NAME);
1573