1// SPDX-License-Identifier: GPL-2.0
2/*
3 * This is a combined i2c adapter and algorithm driver for the
4 * MPC107/Tsi107 PowerPC northbridge and processors that include
5 * the same I2C unit (8240, 8245, 85xx).
6 *
7 * Copyright (C) 2003-2004 Humboldt Solutions Ltd, adrian@humboldt.co.uk
8 * Copyright (C) 2021 Allied Telesis Labs
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/sched/signal.h>
14#include <linux/of.h>
15#include <linux/of_address.h>
16#include <linux/of_irq.h>
17#include <linux/platform_device.h>
18#include <linux/property.h>
19#include <linux/slab.h>
20
21#include <linux/clk.h>
22#include <linux/io.h>
23#include <linux/iopoll.h>
24#include <linux/fsl_devices.h>
25#include <linux/i2c.h>
26#include <linux/interrupt.h>
27#include <linux/delay.h>
28
29#include <asm/mpc52xx.h>
30#include <asm/mpc85xx.h>
31#include <sysdev/fsl_soc.h>
32
33#define MPC_I2C_CLOCK_LEGACY 0
34#define MPC_I2C_CLOCK_PRESERVE (~0U)
35
36#define MPC_I2C_FDR 0x04
37#define MPC_I2C_CR 0x08
38#define MPC_I2C_SR 0x0c
39#define MPC_I2C_DR 0x10
40#define MPC_I2C_DFSRR 0x14
41
42#define CCR_MEN 0x80
43#define CCR_MIEN 0x40
44#define CCR_MSTA 0x20
45#define CCR_MTX 0x10
46#define CCR_TXAK 0x08
47#define CCR_RSTA 0x04
48#define CCR_RSVD 0x02
49
50#define CSR_MCF 0x80
51#define CSR_MAAS 0x40
52#define CSR_MBB 0x20
53#define CSR_MAL 0x10
54#define CSR_SRW 0x04
55#define CSR_MIF 0x02
56#define CSR_RXAK 0x01
57
58enum mpc_i2c_action {
59 MPC_I2C_ACTION_START = 1,
60 MPC_I2C_ACTION_RESTART,
61 MPC_I2C_ACTION_READ_BEGIN,
62 MPC_I2C_ACTION_READ_BYTE,
63 MPC_I2C_ACTION_WRITE,
64 MPC_I2C_ACTION_STOP,
65
66 __MPC_I2C_ACTION_CNT
67};
68
69static const char * const action_str[] = {
70 "invalid",
71 "start",
72 "restart",
73 "read begin",
74 "read",
75 "write",
76 "stop",
77};
78
79static_assert(ARRAY_SIZE(action_str) == __MPC_I2C_ACTION_CNT);
80
81struct mpc_i2c {
82 struct device *dev;
83 void __iomem *base;
84 u32 interrupt;
85 wait_queue_head_t waitq;
86 spinlock_t lock;
87 struct i2c_adapter adap;
88 int irq;
89 u32 real_clk;
90 u8 fdr, dfsrr;
91 struct clk *clk_per;
92 u32 cntl_bits;
93 enum mpc_i2c_action action;
94 struct i2c_msg *msgs;
95 int num_msgs;
96 int curr_msg;
97 u32 byte_posn;
98 u32 block;
99 int rc;
100 int expect_rxack;
101 bool has_errata_A004447;
102};
103
104struct mpc_i2c_divider {
105 u16 divider;
106 u16 fdr; /* including dfsrr */
107};
108
109struct mpc_i2c_data {
110 void (*setup)(struct device_node *node, struct mpc_i2c *i2c, u32 clock);
111};
112
113static inline void writeccr(struct mpc_i2c *i2c, u32 x)
114{
115 writeb(val: x, addr: i2c->base + MPC_I2C_CR);
116}
117
118/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
119 * the bus, because it wants to send ACK.
120 * Following sequence of enabling/disabling and sending start/stop generates
121 * the 9 pulses, each with a START then ending with STOP, so it's all OK.
122 */
123static void mpc_i2c_fixup(struct mpc_i2c *i2c)
124{
125 int k;
126 unsigned long flags;
127
128 for (k = 9; k; k--) {
129 writeccr(i2c, x: 0);
130 writeb(val: 0, addr: i2c->base + MPC_I2C_SR); /* clear any status bits */
131 writeccr(i2c, CCR_MEN | CCR_MSTA); /* START */
132 readb(addr: i2c->base + MPC_I2C_DR); /* init xfer */
133 udelay(15); /* let it hit the bus */
134 local_irq_save(flags); /* should not be delayed further */
135 writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSTA); /* delay SDA */
136 readb(addr: i2c->base + MPC_I2C_DR);
137 if (k != 1)
138 udelay(5);
139 local_irq_restore(flags);
140 }
141 writeccr(i2c, CCR_MEN); /* Initiate STOP */
142 readb(addr: i2c->base + MPC_I2C_DR);
143 udelay(15); /* Let STOP propagate */
144 writeccr(i2c, x: 0);
145}
146
147static int i2c_mpc_wait_sr(struct mpc_i2c *i2c, int mask)
148{
149 void __iomem *addr = i2c->base + MPC_I2C_SR;
150 u8 val;
151
152 return readb_poll_timeout(addr, val, val & mask, 0, 100);
153}
154
155/*
156 * Workaround for Erratum A004447. From the P2040CE Rev Q
157 *
158 * 1. Set up the frequency divider and sampling rate.
159 * 2. I2CCR - a0h
160 * 3. Poll for I2CSR[MBB] to get set.
161 * 4. If I2CSR[MAL] is set (an indication that SDA is stuck low), then go to
162 * step 5. If MAL is not set, then go to step 13.
163 * 5. I2CCR - 00h
164 * 6. I2CCR - 22h
165 * 7. I2CCR - a2h
166 * 8. Poll for I2CSR[MBB] to get set.
167 * 9. Issue read to I2CDR.
168 * 10. Poll for I2CSR[MIF] to be set.
169 * 11. I2CCR - 82h
170 * 12. Workaround complete. Skip the next steps.
171 * 13. Issue read to I2CDR.
172 * 14. Poll for I2CSR[MIF] to be set.
173 * 15. I2CCR - 80h
174 */
175static void mpc_i2c_fixup_A004447(struct mpc_i2c *i2c)
176{
177 int ret;
178 u32 val;
179
180 writeccr(i2c, CCR_MEN | CCR_MSTA);
181 ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
182 if (ret) {
183 dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
184 return;
185 }
186
187 val = readb(addr: i2c->base + MPC_I2C_SR);
188
189 if (val & CSR_MAL) {
190 writeccr(i2c, x: 0x00);
191 writeccr(i2c, CCR_MSTA | CCR_RSVD);
192 writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSVD);
193 ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
194 if (ret) {
195 dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
196 return;
197 }
198 val = readb(addr: i2c->base + MPC_I2C_DR);
199 ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
200 if (ret) {
201 dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
202 return;
203 }
204 writeccr(i2c, CCR_MEN | CCR_RSVD);
205 } else {
206 val = readb(addr: i2c->base + MPC_I2C_DR);
207 ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
208 if (ret) {
209 dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
210 return;
211 }
212 writeccr(i2c, CCR_MEN);
213 }
214}
215
216#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
217static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
218 {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
219 {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
220 {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
221 {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
222 {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
223 {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
224 {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
225 {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
226 {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
227 {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
228 {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
229 {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
230 {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
231 {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
232 {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
233 {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
234 {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
235 {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
236};
237
238static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
239 u32 *real_clk)
240{
241 struct fwnode_handle *fwnode = of_fwnode_handle(node);
242 const struct mpc_i2c_divider *div = NULL;
243 unsigned int pvr = mfspr(SPRN_PVR);
244 u32 divider;
245 int i;
246
247 if (clock == MPC_I2C_CLOCK_LEGACY) {
248 /* see below - default fdr = 0x3f -> div = 2048 */
249 *real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / 2048;
250 return -EINVAL;
251 }
252
253 /* Determine divider value */
254 divider = mpc5xxx_fwnode_get_bus_frequency(fwnode) / clock;
255
256 /*
257 * We want to choose an FDR/DFSR that generates an I2C bus speed that
258 * is equal to or lower than the requested speed.
259 */
260 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
261 div = &mpc_i2c_dividers_52xx[i];
262 /* Old MPC5200 rev A CPUs do not support the high bits */
263 if (div->fdr & 0xc0 && pvr == 0x80822011)
264 continue;
265 if (div->divider >= divider)
266 break;
267 }
268
269 *real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / div->divider;
270 return (int)div->fdr;
271}
272
273static void mpc_i2c_setup_52xx(struct device_node *node,
274 struct mpc_i2c *i2c,
275 u32 clock)
276{
277 int ret, fdr;
278
279 if (clock == MPC_I2C_CLOCK_PRESERVE) {
280 dev_dbg(i2c->dev, "using fdr %d\n",
281 readb(i2c->base + MPC_I2C_FDR));
282 return;
283 }
284
285 ret = mpc_i2c_get_fdr_52xx(node, clock, &i2c->real_clk);
286 fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
287
288 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
289
290 if (ret >= 0)
291 dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
292 fdr);
293}
294#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
295static void mpc_i2c_setup_52xx(struct device_node *node,
296 struct mpc_i2c *i2c,
297 u32 clock)
298{
299}
300#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
301
302#ifdef CONFIG_PPC_MPC512x
303static void mpc_i2c_setup_512x(struct device_node *node,
304 struct mpc_i2c *i2c,
305 u32 clock)
306{
307 struct device_node *node_ctrl;
308 void __iomem *ctrl;
309 u32 idx;
310
311 /* Enable I2C interrupts for mpc5121 */
312 node_ctrl = of_find_compatible_node(NULL, NULL,
313 "fsl,mpc5121-i2c-ctrl");
314 if (node_ctrl) {
315 ctrl = of_iomap(node_ctrl, 0);
316 if (ctrl) {
317 u64 addr;
318 /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
319 of_property_read_reg(node, 0, &addr, NULL);
320 idx = (addr & 0xff) / 0x20;
321 setbits32(ctrl, 1 << (24 + idx * 2));
322 iounmap(ctrl);
323 }
324 of_node_put(node_ctrl);
325 }
326
327 /* The clock setup for the 52xx works also fine for the 512x */
328 mpc_i2c_setup_52xx(node, i2c, clock);
329}
330#else /* CONFIG_PPC_MPC512x */
331static void mpc_i2c_setup_512x(struct device_node *node,
332 struct mpc_i2c *i2c,
333 u32 clock)
334{
335}
336#endif /* CONFIG_PPC_MPC512x */
337
338#ifdef CONFIG_FSL_SOC
339static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
340 {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
341 {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
342 {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
343 {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
344 {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
345 {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
346 {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
347 {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
348 {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
349 {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
350 {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
351 {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
352 {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
353 {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
354 {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
355 {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
356 {49152, 0x011e}, {61440, 0x011f}
357};
358
359static u32 mpc_i2c_get_sec_cfg_8xxx(void)
360{
361 struct device_node *node;
362 u32 __iomem *reg;
363 u32 val = 0;
364
365 node = of_find_node_by_name(NULL, "global-utilities");
366 if (node) {
367 const u32 *prop = of_get_property(node, "reg", NULL);
368 if (prop) {
369 /*
370 * Map and check POR Device Status Register 2
371 * (PORDEVSR2) at 0xE0014. Note than while MPC8533
372 * and MPC8544 indicate SEC frequency ratio
373 * configuration as bit 26 in PORDEVSR2, other MPC8xxx
374 * parts may store it differently or may not have it
375 * at all.
376 */
377 reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
378 if (!reg)
379 printk(KERN_ERR
380 "Error: couldn't map PORDEVSR2\n");
381 else
382 val = in_be32(reg) & 0x00000020; /* sec-cfg */
383 iounmap(reg);
384 }
385 }
386 of_node_put(node);
387
388 return val;
389}
390
391static u32 mpc_i2c_get_prescaler_8xxx(void)
392{
393 /*
394 * According to the AN2919 all MPC824x have prescaler 1, while MPC83xx
395 * may have prescaler 1, 2, or 3, depending on the power-on
396 * configuration.
397 */
398 u32 prescaler = 1;
399
400 /* mpc85xx */
401 if (pvr_version_is(PVR_VER_E500V1) || pvr_version_is(PVR_VER_E500V2)
402 || pvr_version_is(PVR_VER_E500MC)
403 || pvr_version_is(PVR_VER_E5500)
404 || pvr_version_is(PVR_VER_E6500)) {
405 unsigned int svr = mfspr(SPRN_SVR);
406
407 if ((SVR_SOC_VER(svr) == SVR_8540)
408 || (SVR_SOC_VER(svr) == SVR_8541)
409 || (SVR_SOC_VER(svr) == SVR_8560)
410 || (SVR_SOC_VER(svr) == SVR_8555)
411 || (SVR_SOC_VER(svr) == SVR_8610))
412 /* the above 85xx SoCs have prescaler 1 */
413 prescaler = 1;
414 else if ((SVR_SOC_VER(svr) == SVR_8533)
415 || (SVR_SOC_VER(svr) == SVR_8544))
416 /* the above 85xx SoCs have prescaler 3 or 2 */
417 prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
418 else
419 /* all the other 85xx have prescaler 2 */
420 prescaler = 2;
421 }
422
423 return prescaler;
424}
425
426static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
427 u32 *real_clk)
428{
429 const struct mpc_i2c_divider *div = NULL;
430 u32 prescaler = mpc_i2c_get_prescaler_8xxx();
431 u32 divider;
432 int i;
433
434 if (clock == MPC_I2C_CLOCK_LEGACY) {
435 /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
436 *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
437 return -EINVAL;
438 }
439
440 divider = fsl_get_sys_freq() / clock / prescaler;
441
442 pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
443 fsl_get_sys_freq(), clock, divider);
444
445 /*
446 * We want to choose an FDR/DFSR that generates an I2C bus speed that
447 * is equal to or lower than the requested speed.
448 */
449 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
450 div = &mpc_i2c_dividers_8xxx[i];
451 if (div->divider >= divider)
452 break;
453 }
454
455 *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
456 return (int)div->fdr;
457}
458
459static void mpc_i2c_setup_8xxx(struct device_node *node,
460 struct mpc_i2c *i2c,
461 u32 clock)
462{
463 int ret, fdr;
464
465 if (clock == MPC_I2C_CLOCK_PRESERVE) {
466 dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
467 readb(i2c->base + MPC_I2C_DFSRR),
468 readb(i2c->base + MPC_I2C_FDR));
469 return;
470 }
471
472 ret = mpc_i2c_get_fdr_8xxx(node, clock, &i2c->real_clk);
473 fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
474
475 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
476 writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
477
478 if (ret >= 0)
479 dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
480 i2c->real_clk, fdr >> 8, fdr & 0xff);
481}
482
483#else /* !CONFIG_FSL_SOC */
484static void mpc_i2c_setup_8xxx(struct device_node *node,
485 struct mpc_i2c *i2c,
486 u32 clock)
487{
488}
489#endif /* CONFIG_FSL_SOC */
490
491static void mpc_i2c_finish(struct mpc_i2c *i2c, int rc)
492{
493 i2c->rc = rc;
494 i2c->block = 0;
495 i2c->cntl_bits = CCR_MEN;
496 writeccr(i2c, x: i2c->cntl_bits);
497 wake_up(&i2c->waitq);
498}
499
500static void mpc_i2c_do_action(struct mpc_i2c *i2c)
501{
502 struct i2c_msg *msg = NULL;
503 int dir = 0;
504 int recv_len = 0;
505 u8 byte;
506
507 dev_dbg(i2c->dev, "action = %s\n", action_str[i2c->action]);
508
509 i2c->cntl_bits &= ~(CCR_RSTA | CCR_MTX | CCR_TXAK);
510
511 if (i2c->action != MPC_I2C_ACTION_STOP) {
512 msg = &i2c->msgs[i2c->curr_msg];
513 if (msg->flags & I2C_M_RD)
514 dir = 1;
515 if (msg->flags & I2C_M_RECV_LEN)
516 recv_len = 1;
517 }
518
519 switch (i2c->action) {
520 case MPC_I2C_ACTION_RESTART:
521 i2c->cntl_bits |= CCR_RSTA;
522 fallthrough;
523
524 case MPC_I2C_ACTION_START:
525 i2c->cntl_bits |= CCR_MSTA | CCR_MTX;
526 writeccr(i2c, x: i2c->cntl_bits);
527 writeb(val: (msg->addr << 1) | dir, addr: i2c->base + MPC_I2C_DR);
528 i2c->expect_rxack = 1;
529 i2c->action = dir ? MPC_I2C_ACTION_READ_BEGIN : MPC_I2C_ACTION_WRITE;
530 break;
531
532 case MPC_I2C_ACTION_READ_BEGIN:
533 if (msg->len) {
534 if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN))
535 i2c->cntl_bits |= CCR_TXAK;
536
537 writeccr(i2c, x: i2c->cntl_bits);
538 /* Dummy read */
539 readb(addr: i2c->base + MPC_I2C_DR);
540 }
541 i2c->action = MPC_I2C_ACTION_READ_BYTE;
542 break;
543
544 case MPC_I2C_ACTION_READ_BYTE:
545 if (i2c->byte_posn || !recv_len) {
546 /* Generate Tx ACK on next to last byte */
547 if (i2c->byte_posn == msg->len - 2)
548 i2c->cntl_bits |= CCR_TXAK;
549 /* Do not generate stop on last byte */
550 if (i2c->byte_posn == msg->len - 1)
551 i2c->cntl_bits |= CCR_MTX;
552
553 writeccr(i2c, x: i2c->cntl_bits);
554 }
555
556 byte = readb(addr: i2c->base + MPC_I2C_DR);
557
558 if (i2c->byte_posn == 0 && recv_len) {
559 if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX) {
560 mpc_i2c_finish(i2c, rc: -EPROTO);
561 return;
562 }
563 msg->len += byte;
564 /*
565 * For block reads, generate Tx ACK here if data length
566 * is 1 byte (total length is 2 bytes).
567 */
568 if (msg->len == 2) {
569 i2c->cntl_bits |= CCR_TXAK;
570 writeccr(i2c, x: i2c->cntl_bits);
571 }
572 }
573
574 dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action], byte);
575 msg->buf[i2c->byte_posn++] = byte;
576 break;
577
578 case MPC_I2C_ACTION_WRITE:
579 dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action],
580 msg->buf[i2c->byte_posn]);
581 writeb(val: msg->buf[i2c->byte_posn++], addr: i2c->base + MPC_I2C_DR);
582 i2c->expect_rxack = 1;
583 break;
584
585 case MPC_I2C_ACTION_STOP:
586 mpc_i2c_finish(i2c, rc: 0);
587 break;
588
589 default:
590 WARN(1, "Unexpected action %d\n", i2c->action);
591 break;
592 }
593
594 if (msg && msg->len == i2c->byte_posn) {
595 i2c->curr_msg++;
596 i2c->byte_posn = 0;
597
598 if (i2c->curr_msg == i2c->num_msgs) {
599 i2c->action = MPC_I2C_ACTION_STOP;
600 /*
601 * We don't get another interrupt on read so
602 * finish the transfer now
603 */
604 if (dir)
605 mpc_i2c_finish(i2c, rc: 0);
606 } else {
607 i2c->action = MPC_I2C_ACTION_RESTART;
608 }
609 }
610}
611
612static void mpc_i2c_do_intr(struct mpc_i2c *i2c, u8 status)
613{
614 spin_lock(lock: &i2c->lock);
615
616 if (!(status & CSR_MCF)) {
617 dev_dbg(i2c->dev, "unfinished\n");
618 mpc_i2c_finish(i2c, rc: -EIO);
619 goto out;
620 }
621
622 if (status & CSR_MAL) {
623 dev_dbg(i2c->dev, "arbitration lost\n");
624 mpc_i2c_finish(i2c, rc: -EAGAIN);
625 goto out;
626 }
627
628 if (i2c->expect_rxack && (status & CSR_RXAK)) {
629 dev_dbg(i2c->dev, "no Rx ACK\n");
630 mpc_i2c_finish(i2c, rc: -ENXIO);
631 goto out;
632 }
633 i2c->expect_rxack = 0;
634
635 mpc_i2c_do_action(i2c);
636
637out:
638 spin_unlock(lock: &i2c->lock);
639}
640
641static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
642{
643 struct mpc_i2c *i2c = dev_id;
644 u8 status;
645
646 status = readb(addr: i2c->base + MPC_I2C_SR);
647 if (status & CSR_MIF) {
648 /* Wait up to 100us for transfer to properly complete */
649 readb_poll_timeout_atomic(i2c->base + MPC_I2C_SR, status, status & CSR_MCF, 0, 100);
650 writeb(val: 0, addr: i2c->base + MPC_I2C_SR);
651 mpc_i2c_do_intr(i2c, status);
652 return IRQ_HANDLED;
653 }
654 return IRQ_NONE;
655}
656
657static int mpc_i2c_wait_for_completion(struct mpc_i2c *i2c)
658{
659 long time_left;
660
661 time_left = wait_event_timeout(i2c->waitq, !i2c->block, i2c->adap.timeout);
662 if (!time_left)
663 return -ETIMEDOUT;
664 if (time_left < 0)
665 return time_left;
666
667 return 0;
668}
669
670static int mpc_i2c_execute_msg(struct mpc_i2c *i2c)
671{
672 unsigned long orig_jiffies;
673 unsigned long flags;
674 int ret;
675
676 spin_lock_irqsave(&i2c->lock, flags);
677
678 i2c->curr_msg = 0;
679 i2c->rc = 0;
680 i2c->byte_posn = 0;
681 i2c->block = 1;
682 i2c->action = MPC_I2C_ACTION_START;
683
684 i2c->cntl_bits = CCR_MEN | CCR_MIEN;
685 writeb(val: 0, addr: i2c->base + MPC_I2C_SR);
686 writeccr(i2c, x: i2c->cntl_bits);
687
688 mpc_i2c_do_action(i2c);
689
690 spin_unlock_irqrestore(lock: &i2c->lock, flags);
691
692 ret = mpc_i2c_wait_for_completion(i2c);
693 if (ret)
694 i2c->rc = ret;
695
696 if (i2c->rc == -EIO || i2c->rc == -EAGAIN || i2c->rc == -ETIMEDOUT)
697 i2c_recover_bus(adap: &i2c->adap);
698
699 orig_jiffies = jiffies;
700 /* Wait until STOP is seen, allow up to 1 s */
701 while (readb(addr: i2c->base + MPC_I2C_SR) & CSR_MBB) {
702 if (time_after(jiffies, orig_jiffies + HZ)) {
703 u8 status = readb(addr: i2c->base + MPC_I2C_SR);
704
705 dev_dbg(i2c->dev, "timeout\n");
706 if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
707 writeb(val: status & ~CSR_MAL,
708 addr: i2c->base + MPC_I2C_SR);
709 i2c_recover_bus(adap: &i2c->adap);
710 }
711 return -EIO;
712 }
713 cond_resched();
714 }
715
716 return i2c->rc;
717}
718
719static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
720{
721 int rc, ret = num;
722 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
723 int i;
724
725 dev_dbg(i2c->dev, "num = %d\n", num);
726 for (i = 0; i < num; i++)
727 dev_dbg(i2c->dev, " addr = %02x, flags = %02x, len = %d, %*ph\n",
728 msgs[i].addr, msgs[i].flags, msgs[i].len,
729 msgs[i].flags & I2C_M_RD ? 0 : msgs[i].len,
730 msgs[i].buf);
731
732 WARN_ON(i2c->msgs != NULL);
733 i2c->msgs = msgs;
734 i2c->num_msgs = num;
735
736 rc = mpc_i2c_execute_msg(i2c);
737 if (rc < 0)
738 ret = rc;
739
740 i2c->num_msgs = 0;
741 i2c->msgs = NULL;
742
743 return ret;
744}
745
746static u32 mpc_functionality(struct i2c_adapter *adap)
747{
748 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
749 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
750}
751
752static int fsl_i2c_bus_recovery(struct i2c_adapter *adap)
753{
754 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
755
756 if (i2c->has_errata_A004447)
757 mpc_i2c_fixup_A004447(i2c);
758 else
759 mpc_i2c_fixup(i2c);
760
761 return 0;
762}
763
764static const struct i2c_algorithm mpc_algo = {
765 .master_xfer = mpc_xfer,
766 .functionality = mpc_functionality,
767};
768
769static struct i2c_adapter mpc_ops = {
770 .owner = THIS_MODULE,
771 .algo = &mpc_algo,
772};
773
774static struct i2c_bus_recovery_info fsl_i2c_recovery_info = {
775 .recover_bus = fsl_i2c_bus_recovery,
776};
777
778static int fsl_i2c_probe(struct platform_device *op)
779{
780 const struct mpc_i2c_data *data;
781 struct mpc_i2c *i2c;
782 struct clk *clk;
783 int result;
784 u32 clock;
785 int err;
786
787 i2c = devm_kzalloc(dev: &op->dev, size: sizeof(*i2c), GFP_KERNEL);
788 if (!i2c)
789 return -ENOMEM;
790
791 i2c->dev = &op->dev; /* for debug and error output */
792
793 init_waitqueue_head(&i2c->waitq);
794 spin_lock_init(&i2c->lock);
795
796 i2c->base = devm_platform_ioremap_resource(pdev: op, index: 0);
797 if (IS_ERR(ptr: i2c->base))
798 return PTR_ERR(ptr: i2c->base);
799
800 i2c->irq = platform_get_irq(op, 0);
801 if (i2c->irq < 0)
802 return i2c->irq;
803
804 result = devm_request_irq(dev: &op->dev, irq: i2c->irq, handler: mpc_i2c_isr,
805 IRQF_SHARED, devname: "i2c-mpc", dev_id: i2c);
806 if (result < 0) {
807 dev_err(i2c->dev, "failed to attach interrupt\n");
808 return result;
809 }
810
811 /*
812 * enable clock for the I2C peripheral (non fatal),
813 * keep a reference upon successful allocation
814 */
815 clk = devm_clk_get_optional(dev: &op->dev, NULL);
816 if (IS_ERR(ptr: clk))
817 return PTR_ERR(ptr: clk);
818
819 err = clk_prepare_enable(clk);
820 if (err) {
821 dev_err(&op->dev, "failed to enable clock\n");
822 return err;
823 }
824
825 i2c->clk_per = clk;
826
827 if (of_property_read_bool(np: op->dev.of_node, propname: "fsl,preserve-clocking")) {
828 clock = MPC_I2C_CLOCK_PRESERVE;
829 } else {
830 result = of_property_read_u32(np: op->dev.of_node,
831 propname: "clock-frequency", out_value: &clock);
832 if (result)
833 clock = MPC_I2C_CLOCK_LEGACY;
834 }
835
836 data = device_get_match_data(dev: &op->dev);
837 if (data) {
838 data->setup(op->dev.of_node, i2c, clock);
839 } else {
840 /* Backwards compatibility */
841 if (of_property_read_bool(np: op->dev.of_node, propname: "dfsrr"))
842 mpc_i2c_setup_8xxx(node: op->dev.of_node, i2c, clock);
843 }
844
845 /* Sadly, we have to support two deprecated bindings here */
846 result = of_property_read_u32(np: op->dev.of_node,
847 propname: "i2c-transfer-timeout-us",
848 out_value: &mpc_ops.timeout);
849 if (result == -EINVAL)
850 result = of_property_read_u32(np: op->dev.of_node,
851 propname: "i2c-scl-clk-low-timeout-us",
852 out_value: &mpc_ops.timeout);
853 if (result == -EINVAL)
854 result = of_property_read_u32(np: op->dev.of_node,
855 propname: "fsl,timeout", out_value: &mpc_ops.timeout);
856
857 if (!result) {
858 mpc_ops.timeout *= HZ / 1000000;
859 if (mpc_ops.timeout < 5)
860 mpc_ops.timeout = 5;
861 } else {
862 mpc_ops.timeout = HZ;
863 }
864
865 dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
866
867 if (of_property_read_bool(np: op->dev.of_node, propname: "fsl,i2c-erratum-a004447"))
868 i2c->has_errata_A004447 = true;
869
870 i2c->adap = mpc_ops;
871 scnprintf(buf: i2c->adap.name, size: sizeof(i2c->adap.name),
872 fmt: "MPC adapter (%s)", of_node_full_name(np: op->dev.of_node));
873 i2c->adap.dev.parent = &op->dev;
874 i2c->adap.nr = op->id;
875 i2c->adap.dev.of_node = of_node_get(node: op->dev.of_node);
876 i2c->adap.bus_recovery_info = &fsl_i2c_recovery_info;
877 platform_set_drvdata(pdev: op, data: i2c);
878 i2c_set_adapdata(adap: &i2c->adap, data: i2c);
879
880 result = i2c_add_numbered_adapter(adap: &i2c->adap);
881 if (result)
882 goto fail_add;
883
884 return 0;
885
886 fail_add:
887 clk_disable_unprepare(clk: i2c->clk_per);
888
889 return result;
890};
891
892static void fsl_i2c_remove(struct platform_device *op)
893{
894 struct mpc_i2c *i2c = platform_get_drvdata(pdev: op);
895
896 i2c_del_adapter(adap: &i2c->adap);
897
898 clk_disable_unprepare(clk: i2c->clk_per);
899};
900
901static int __maybe_unused mpc_i2c_suspend(struct device *dev)
902{
903 struct mpc_i2c *i2c = dev_get_drvdata(dev);
904
905 i2c->fdr = readb(addr: i2c->base + MPC_I2C_FDR);
906 i2c->dfsrr = readb(addr: i2c->base + MPC_I2C_DFSRR);
907
908 return 0;
909}
910
911static int __maybe_unused mpc_i2c_resume(struct device *dev)
912{
913 struct mpc_i2c *i2c = dev_get_drvdata(dev);
914
915 writeb(val: i2c->fdr, addr: i2c->base + MPC_I2C_FDR);
916 writeb(val: i2c->dfsrr, addr: i2c->base + MPC_I2C_DFSRR);
917
918 return 0;
919}
920static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
921
922static const struct mpc_i2c_data mpc_i2c_data_512x = {
923 .setup = mpc_i2c_setup_512x,
924};
925
926static const struct mpc_i2c_data mpc_i2c_data_52xx = {
927 .setup = mpc_i2c_setup_52xx,
928};
929
930static const struct mpc_i2c_data mpc_i2c_data_8313 = {
931 .setup = mpc_i2c_setup_8xxx,
932};
933
934static const struct mpc_i2c_data mpc_i2c_data_8543 = {
935 .setup = mpc_i2c_setup_8xxx,
936};
937
938static const struct mpc_i2c_data mpc_i2c_data_8544 = {
939 .setup = mpc_i2c_setup_8xxx,
940};
941
942static const struct of_device_id mpc_i2c_of_match[] = {
943 {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
944 {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
945 {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
946 {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
947 {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
948 {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
949 {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
950 /* Backward compatibility */
951 {.compatible = "fsl-i2c", },
952 {},
953};
954MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
955
956/* Structure for a device driver */
957static struct platform_driver mpc_i2c_driver = {
958 .probe = fsl_i2c_probe,
959 .remove_new = fsl_i2c_remove,
960 .driver = {
961 .name = "mpc-i2c",
962 .of_match_table = mpc_i2c_of_match,
963 .pm = &mpc_i2c_pm_ops,
964 },
965};
966
967module_platform_driver(mpc_i2c_driver);
968
969MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
970MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
971 "MPC824x/83xx/85xx/86xx/512x/52xx processors");
972MODULE_LICENSE("GPL");
973

source code of linux/drivers/i2c/busses/i2c-mpc.c