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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_address.h>
15#include <linux/of_irq.h>
16#include <linux/of_platform.h>
17#include <linux/property.h>
18#include <linux/slab.h>
19
20#include <linux/clk.h>
21#include <linux/io.h>
22#include <linux/iopoll.h>
23#include <linux/fsl_devices.h>
24#include <linux/i2c.h>
25#include <linux/interrupt.h>
26#include <linux/delay.h>
27
28#include <asm/mpc52xx.h>
29#include <asm/mpc85xx.h>
30#include <sysdev/fsl_soc.h>
31
32#define DRV_NAME "mpc-i2c"
33
34#define MPC_I2C_CLOCK_LEGACY 0
35#define MPC_I2C_CLOCK_PRESERVE (~0U)
36
37#define MPC_I2C_FDR 0x04
38#define MPC_I2C_CR 0x08
39#define MPC_I2C_SR 0x0c
40#define MPC_I2C_DR 0x10
41#define MPC_I2C_DFSRR 0x14
42
43#define CCR_MEN 0x80
44#define CCR_MIEN 0x40
45#define CCR_MSTA 0x20
46#define CCR_MTX 0x10
47#define CCR_TXAK 0x08
48#define CCR_RSTA 0x04
49#define CCR_RSVD 0x02
50
51#define CSR_MCF 0x80
52#define CSR_MAAS 0x40
53#define CSR_MBB 0x20
54#define CSR_MAL 0x10
55#define CSR_SRW 0x04
56#define CSR_MIF 0x02
57#define CSR_RXAK 0x01
58
59enum mpc_i2c_action {
60 MPC_I2C_ACTION_START = 1,
61 MPC_I2C_ACTION_RESTART,
62 MPC_I2C_ACTION_READ_BEGIN,
63 MPC_I2C_ACTION_READ_BYTE,
64 MPC_I2C_ACTION_WRITE,
65 MPC_I2C_ACTION_STOP,
66
67 __MPC_I2C_ACTION_CNT
68};
69
70static const char * const action_str[] = {
71 "invalid",
72 "start",
73 "restart",
74 "read begin",
75 "read",
76 "write",
77 "stop",
78};
79
80static_assert(ARRAY_SIZE(action_str) == __MPC_I2C_ACTION_CNT);
81
82struct mpc_i2c {
83 struct device *dev;
84 void __iomem *base;
85 u32 interrupt;
86 wait_queue_head_t waitq;
87 spinlock_t lock;
88 struct i2c_adapter adap;
89 int irq;
90 u32 real_clk;
91 u8 fdr, dfsrr;
92 struct clk *clk_per;
93 u32 cntl_bits;
94 enum mpc_i2c_action action;
95 struct i2c_msg *msgs;
96 int num_msgs;
97 int curr_msg;
98 u32 byte_posn;
99 u32 block;
100 int rc;
101 int expect_rxack;
102 bool has_errata_A004447;
103};
104
105struct mpc_i2c_divider {
106 u16 divider;
107 u16 fdr; /* including dfsrr */
108};
109
110struct mpc_i2c_data {
111 void (*setup)(struct device_node *node, struct mpc_i2c *i2c, u32 clock);
112};
113
114static inline void writeccr(struct mpc_i2c *i2c, u32 x)
115{
116 writeb(x, i2c->base + MPC_I2C_CR);
117}
118
119/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
120 * the bus, because it wants to send ACK.
121 * Following sequence of enabling/disabling and sending start/stop generates
122 * the 9 pulses, each with a START then ending with STOP, so it's all OK.
123 */
124static void mpc_i2c_fixup(struct mpc_i2c *i2c)
125{
126 int k;
127 unsigned long flags;
128
129 for (k = 9; k; k--) {
130 writeccr(i2c, 0);
131 writeb(0, i2c->base + MPC_I2C_SR); /* clear any status bits */
132 writeccr(i2c, CCR_MEN | CCR_MSTA); /* START */
133 readb(i2c->base + MPC_I2C_DR); /* init xfer */
134 udelay(15); /* let it hit the bus */
135 local_irq_save(flags); /* should not be delayed further */
136 writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSTA); /* delay SDA */
137 readb(i2c->base + MPC_I2C_DR);
138 if (k != 1)
139 udelay(5);
140 local_irq_restore(flags);
141 }
142 writeccr(i2c, CCR_MEN); /* Initiate STOP */
143 readb(i2c->base + MPC_I2C_DR);
144 udelay(15); /* Let STOP propagate */
145 writeccr(i2c, 0);
146}
147
148static int i2c_mpc_wait_sr(struct mpc_i2c *i2c, int mask)
149{
150 void __iomem *addr = i2c->base + MPC_I2C_SR;
151 u8 val;
152
153 return readb_poll_timeout(addr, val, val & mask, 0, 100);
154}
155
156/*
157 * Workaround for Erratum A004447. From the P2040CE Rev Q
158 *
159 * 1. Set up the frequency divider and sampling rate.
160 * 2. I2CCR - a0h
161 * 3. Poll for I2CSR[MBB] to get set.
162 * 4. If I2CSR[MAL] is set (an indication that SDA is stuck low), then go to
163 * step 5. If MAL is not set, then go to step 13.
164 * 5. I2CCR - 00h
165 * 6. I2CCR - 22h
166 * 7. I2CCR - a2h
167 * 8. Poll for I2CSR[MBB] to get set.
168 * 9. Issue read to I2CDR.
169 * 10. Poll for I2CSR[MIF] to be set.
170 * 11. I2CCR - 82h
171 * 12. Workaround complete. Skip the next steps.
172 * 13. Issue read to I2CDR.
173 * 14. Poll for I2CSR[MIF] to be set.
174 * 15. I2CCR - 80h
175 */
176static void mpc_i2c_fixup_A004447(struct mpc_i2c *i2c)
177{
178 int ret;
179 u32 val;
180
181 writeccr(i2c, CCR_MEN | CCR_MSTA);
182 ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
183 if (ret) {
184 dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
185 return;
186 }
187
188 val = readb(i2c->base + MPC_I2C_SR);
189
190 if (val & CSR_MAL) {
191 writeccr(i2c, 0x00);
192 writeccr(i2c, CCR_MSTA | CCR_RSVD);
193 writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSVD);
194 ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
195 if (ret) {
196 dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
197 return;
198 }
199 val = readb(i2c->base + MPC_I2C_DR);
200 ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
201 if (ret) {
202 dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
203 return;
204 }
205 writeccr(i2c, CCR_MEN | CCR_RSVD);
206 } else {
207 val = readb(i2c->base + MPC_I2C_DR);
208 ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
209 if (ret) {
210 dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
211 return;
212 }
213 writeccr(i2c, CCR_MEN);
214 }
215}
216
217#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
218static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
219 {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
220 {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
221 {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
222 {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
223 {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
224 {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
225 {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
226 {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
227 {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
228 {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
229 {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
230 {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
231 {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
232 {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
233 {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
234 {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
235 {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
236 {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
237};
238
239static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
240 u32 *real_clk)
241{
242 struct fwnode_handle *fwnode = of_fwnode_handle(node);
243 const struct mpc_i2c_divider *div = NULL;
244 unsigned int pvr = mfspr(SPRN_PVR);
245 u32 divider;
246 int i;
247
248 if (clock == MPC_I2C_CLOCK_LEGACY) {
249 /* see below - default fdr = 0x3f -> div = 2048 */
250 *real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / 2048;
251 return -EINVAL;
252 }
253
254 /* Determine divider value */
255 divider = mpc5xxx_fwnode_get_bus_frequency(fwnode) / clock;
256
257 /*
258 * We want to choose an FDR/DFSR that generates an I2C bus speed that
259 * is equal to or lower than the requested speed.
260 */
261 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
262 div = &mpc_i2c_dividers_52xx[i];
263 /* Old MPC5200 rev A CPUs do not support the high bits */
264 if (div->fdr & 0xc0 && pvr == 0x80822011)
265 continue;
266 if (div->divider >= divider)
267 break;
268 }
269
270 *real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / div->divider;
271 return (int)div->fdr;
272}
273
274static void mpc_i2c_setup_52xx(struct device_node *node,
275 struct mpc_i2c *i2c,
276 u32 clock)
277{
278 int ret, fdr;
279
280 if (clock == MPC_I2C_CLOCK_PRESERVE) {
281 dev_dbg(i2c->dev, "using fdr %d\n",
282 readb(i2c->base + MPC_I2C_FDR));
283 return;
284 }
285
286 ret = mpc_i2c_get_fdr_52xx(node, clock, &i2c->real_clk);
287 fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
288
289 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
290
291 if (ret >= 0)
292 dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
293 fdr);
294}
295#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
296static void mpc_i2c_setup_52xx(struct device_node *node,
297 struct mpc_i2c *i2c,
298 u32 clock)
299{
300}
301#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
302
303#ifdef CONFIG_PPC_MPC512x
304static void mpc_i2c_setup_512x(struct device_node *node,
305 struct mpc_i2c *i2c,
306 u32 clock)
307{
308 struct device_node *node_ctrl;
309 void __iomem *ctrl;
310 const u32 *pval;
311 u32 idx;
312
313 /* Enable I2C interrupts for mpc5121 */
314 node_ctrl = of_find_compatible_node(NULL, NULL,
315 "fsl,mpc5121-i2c-ctrl");
316 if (node_ctrl) {
317 ctrl = of_iomap(node_ctrl, 0);
318 if (ctrl) {
319 /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
320 pval = of_get_property(node, "reg", NULL);
321 idx = (*pval & 0xff) / 0x20;
322 setbits32(ctrl, 1 << (24 + idx * 2));
323 iounmap(ctrl);
324 }
325 of_node_put(node_ctrl);
326 }
327
328 /* The clock setup for the 52xx works also fine for the 512x */
329 mpc_i2c_setup_52xx(node, i2c, clock);
330}
331#else /* CONFIG_PPC_MPC512x */
332static void mpc_i2c_setup_512x(struct device_node *node,
333 struct mpc_i2c *i2c,
334 u32 clock)
335{
336}
337#endif /* CONFIG_PPC_MPC512x */
338
339#ifdef CONFIG_FSL_SOC
340static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
341 {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
342 {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
343 {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
344 {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
345 {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
346 {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
347 {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
348 {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
349 {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
350 {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
351 {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
352 {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
353 {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
354 {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
355 {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
356 {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
357 {49152, 0x011e}, {61440, 0x011f}
358};
359
360static u32 mpc_i2c_get_sec_cfg_8xxx(void)
361{
362 struct device_node *node;
363 u32 __iomem *reg;
364 u32 val = 0;
365
366 node = of_find_node_by_name(NULL, "global-utilities");
367 if (node) {
368 const u32 *prop = of_get_property(node, "reg", NULL);
369 if (prop) {
370 /*
371 * Map and check POR Device Status Register 2
372 * (PORDEVSR2) at 0xE0014. Note than while MPC8533
373 * and MPC8544 indicate SEC frequency ratio
374 * configuration as bit 26 in PORDEVSR2, other MPC8xxx
375 * parts may store it differently or may not have it
376 * at all.
377 */
378 reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
379 if (!reg)
380 printk(KERN_ERR
381 "Error: couldn't map PORDEVSR2\n");
382 else
383 val = in_be32(reg) & 0x00000020; /* sec-cfg */
384 iounmap(reg);
385 }
386 }
387 of_node_put(node);
388
389 return val;
390}
391
392static u32 mpc_i2c_get_prescaler_8xxx(void)
393{
394 /*
395 * According to the AN2919 all MPC824x have prescaler 1, while MPC83xx
396 * may have prescaler 1, 2, or 3, depending on the power-on
397 * configuration.
398 */
399 u32 prescaler = 1;
400
401 /* mpc85xx */
402 if (pvr_version_is(PVR_VER_E500V1) || pvr_version_is(PVR_VER_E500V2)
403 || pvr_version_is(PVR_VER_E500MC)
404 || pvr_version_is(PVR_VER_E5500)
405 || pvr_version_is(PVR_VER_E6500)) {
406 unsigned int svr = mfspr(SPRN_SVR);
407
408 if ((SVR_SOC_VER(svr) == SVR_8540)
409 || (SVR_SOC_VER(svr) == SVR_8541)
410 || (SVR_SOC_VER(svr) == SVR_8560)
411 || (SVR_SOC_VER(svr) == SVR_8555)
412 || (SVR_SOC_VER(svr) == SVR_8610))
413 /* the above 85xx SoCs have prescaler 1 */
414 prescaler = 1;
415 else if ((SVR_SOC_VER(svr) == SVR_8533)
416 || (SVR_SOC_VER(svr) == SVR_8544))
417 /* the above 85xx SoCs have prescaler 3 or 2 */
418 prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
419 else
420 /* all the other 85xx have prescaler 2 */
421 prescaler = 2;
422 }
423
424 return prescaler;
425}
426
427static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
428 u32 *real_clk)
429{
430 const struct mpc_i2c_divider *div = NULL;
431 u32 prescaler = mpc_i2c_get_prescaler_8xxx();
432 u32 divider;
433 int i;
434
435 if (clock == MPC_I2C_CLOCK_LEGACY) {
436 /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
437 *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
438 return -EINVAL;
439 }
440
441 divider = fsl_get_sys_freq() / clock / prescaler;
442
443 pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
444 fsl_get_sys_freq(), clock, divider);
445
446 /*
447 * We want to choose an FDR/DFSR that generates an I2C bus speed that
448 * is equal to or lower than the requested speed.
449 */
450 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
451 div = &mpc_i2c_dividers_8xxx[i];
452 if (div->divider >= divider)
453 break;
454 }
455
456 *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
457 return (int)div->fdr;
458}
459
460static void mpc_i2c_setup_8xxx(struct device_node *node,
461 struct mpc_i2c *i2c,
462 u32 clock)
463{
464 int ret, fdr;
465
466 if (clock == MPC_I2C_CLOCK_PRESERVE) {
467 dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
468 readb(i2c->base + MPC_I2C_DFSRR),
469 readb(i2c->base + MPC_I2C_FDR));
470 return;
471 }
472
473 ret = mpc_i2c_get_fdr_8xxx(node, clock, &i2c->real_clk);
474 fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
475
476 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
477 writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
478
479 if (ret >= 0)
480 dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
481 i2c->real_clk, fdr >> 8, fdr & 0xff);
482}
483
484#else /* !CONFIG_FSL_SOC */
485static void mpc_i2c_setup_8xxx(struct device_node *node,
486 struct mpc_i2c *i2c,
487 u32 clock)
488{
489}
490#endif /* CONFIG_FSL_SOC */
491
492static void mpc_i2c_finish(struct mpc_i2c *i2c, int rc)
493{
494 i2c->rc = rc;
495 i2c->block = 0;
496 i2c->cntl_bits = CCR_MEN;
497 writeccr(i2c, i2c->cntl_bits);
498 wake_up(&i2c->waitq);
499}
500
501static void mpc_i2c_do_action(struct mpc_i2c *i2c)
502{
503 struct i2c_msg *msg = NULL;
504 int dir = 0;
505 int recv_len = 0;
506 u8 byte;
507
508 dev_dbg(i2c->dev, "action = %s\n", action_str[i2c->action]);
509
510 i2c->cntl_bits &= ~(CCR_RSTA | CCR_MTX | CCR_TXAK);
511
512 if (i2c->action != MPC_I2C_ACTION_STOP) {
513 msg = &i2c->msgs[i2c->curr_msg];
514 if (msg->flags & I2C_M_RD)
515 dir = 1;
516 if (msg->flags & I2C_M_RECV_LEN)
517 recv_len = 1;
518 }
519
520 switch (i2c->action) {
521 case MPC_I2C_ACTION_RESTART:
522 i2c->cntl_bits |= CCR_RSTA;
523 fallthrough;
524
525 case MPC_I2C_ACTION_START:
526 i2c->cntl_bits |= CCR_MSTA | CCR_MTX;
527 writeccr(i2c, i2c->cntl_bits);
528 writeb((msg->addr << 1) | dir, i2c->base + MPC_I2C_DR);
529 i2c->expect_rxack = 1;
530 i2c->action = dir ? MPC_I2C_ACTION_READ_BEGIN : MPC_I2C_ACTION_WRITE;
531 break;
532
533 case MPC_I2C_ACTION_READ_BEGIN:
534 if (msg->len) {
535 if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN))
536 i2c->cntl_bits |= CCR_TXAK;
537
538 writeccr(i2c, i2c->cntl_bits);
539 /* Dummy read */
540 readb(i2c->base + MPC_I2C_DR);
541 }
542 i2c->action = MPC_I2C_ACTION_READ_BYTE;
543 break;
544
545 case MPC_I2C_ACTION_READ_BYTE:
546 if (i2c->byte_posn || !recv_len) {
547 /* Generate Tx ACK on next to last byte */
548 if (i2c->byte_posn == msg->len - 2)
549 i2c->cntl_bits |= CCR_TXAK;
550 /* Do not generate stop on last byte */
551 if (i2c->byte_posn == msg->len - 1)
552 i2c->cntl_bits |= CCR_MTX;
553
554 writeccr(i2c, i2c->cntl_bits);
555 }
556
557 byte = readb(i2c->base + MPC_I2C_DR);
558
559 if (i2c->byte_posn == 0 && recv_len) {
560 if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX) {
561 mpc_i2c_finish(i2c, -EPROTO);
562 return;
563 }
564 msg->len += byte;
565 /*
566 * For block reads, generate Tx ACK here if data length
567 * is 1 byte (total length is 2 bytes).
568 */
569 if (msg->len == 2) {
570 i2c->cntl_bits |= CCR_TXAK;
571 writeccr(i2c, i2c->cntl_bits);
572 }
573 }
574
575 dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action], byte);
576 msg->buf[i2c->byte_posn++] = byte;
577 break;
578
579 case MPC_I2C_ACTION_WRITE:
580 dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action],
581 msg->buf[i2c->byte_posn]);
582 writeb(msg->buf[i2c->byte_posn++], i2c->base + MPC_I2C_DR);
583 i2c->expect_rxack = 1;
584 break;
585
586 case MPC_I2C_ACTION_STOP:
587 mpc_i2c_finish(i2c, 0);
588 break;
589
590 default:
591 WARN(1, "Unexpected action %d\n", i2c->action);
592 break;
593 }
594
595 if (msg && msg->len == i2c->byte_posn) {
596 i2c->curr_msg++;
597 i2c->byte_posn = 0;
598
599 if (i2c->curr_msg == i2c->num_msgs) {
600 i2c->action = MPC_I2C_ACTION_STOP;
601 /*
602 * We don't get another interrupt on read so
603 * finish the transfer now
604 */
605 if (dir)
606 mpc_i2c_finish(i2c, 0);
607 } else {
608 i2c->action = MPC_I2C_ACTION_RESTART;
609 }
610 }
611}
612
613static void mpc_i2c_do_intr(struct mpc_i2c *i2c, u8 status)
614{
615 spin_lock(&i2c->lock);
616
617 if (!(status & CSR_MCF)) {
618 dev_dbg(i2c->dev, "unfinished\n");
619 mpc_i2c_finish(i2c, -EIO);
620 goto out;
621 }
622
623 if (status & CSR_MAL) {
624 dev_dbg(i2c->dev, "arbitration lost\n");
625 mpc_i2c_finish(i2c, -EAGAIN);
626 goto out;
627 }
628
629 if (i2c->expect_rxack && (status & CSR_RXAK)) {
630 dev_dbg(i2c->dev, "no Rx ACK\n");
631 mpc_i2c_finish(i2c, -ENXIO);
632 goto out;
633 }
634 i2c->expect_rxack = 0;
635
636 mpc_i2c_do_action(i2c);
637
638out:
639 spin_unlock(&i2c->lock);
640}
641
642static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
643{
644 struct mpc_i2c *i2c = dev_id;
645 u8 status;
646
647 status = readb(i2c->base + MPC_I2C_SR);
648 if (status & CSR_MIF) {
649 /* Wait up to 100us for transfer to properly complete */
650 readb_poll_timeout_atomic(i2c->base + MPC_I2C_SR, status, status & CSR_MCF, 0, 100);
651 writeb(0, i2c->base + MPC_I2C_SR);
652 mpc_i2c_do_intr(i2c, status);
653 return IRQ_HANDLED;
654 }
655 return IRQ_NONE;
656}
657
658static int mpc_i2c_wait_for_completion(struct mpc_i2c *i2c)
659{
660 long time_left;
661
662 time_left = wait_event_timeout(i2c->waitq, !i2c->block, i2c->adap.timeout);
663 if (!time_left)
664 return -ETIMEDOUT;
665 if (time_left < 0)
666 return time_left;
667
668 return 0;
669}
670
671static int mpc_i2c_execute_msg(struct mpc_i2c *i2c)
672{
673 unsigned long orig_jiffies;
674 unsigned long flags;
675 int ret;
676
677 spin_lock_irqsave(&i2c->lock, flags);
678
679 i2c->curr_msg = 0;
680 i2c->rc = 0;
681 i2c->byte_posn = 0;
682 i2c->block = 1;
683 i2c->action = MPC_I2C_ACTION_START;
684
685 i2c->cntl_bits = CCR_MEN | CCR_MIEN;
686 writeb(0, i2c->base + MPC_I2C_SR);
687 writeccr(i2c, i2c->cntl_bits);
688
689 mpc_i2c_do_action(i2c);
690
691 spin_unlock_irqrestore(&i2c->lock, flags);
692
693 ret = mpc_i2c_wait_for_completion(i2c);
694 if (ret)
695 i2c->rc = ret;
696
697 if (i2c->rc == -EIO || i2c->rc == -EAGAIN || i2c->rc == -ETIMEDOUT)
698 i2c_recover_bus(&i2c->adap);
699
700 orig_jiffies = jiffies;
701 /* Wait until STOP is seen, allow up to 1 s */
702 while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
703 if (time_after(jiffies, orig_jiffies + HZ)) {
704 u8 status = readb(i2c->base + MPC_I2C_SR);
705
706 dev_dbg(i2c->dev, "timeout\n");
707 if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
708 writeb(status & ~CSR_MAL,
709 i2c->base + MPC_I2C_SR);
710 i2c_recover_bus(&i2c->adap);
711 }
712 return -EIO;
713 }
714 cond_resched();
715 }
716
717 return i2c->rc;
718}
719
720static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
721{
722 int rc, ret = num;
723 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
724 int i;
725
726 dev_dbg(i2c->dev, "num = %d\n", num);
727 for (i = 0; i < num; i++)
728 dev_dbg(i2c->dev, " addr = %02x, flags = %02x, len = %d, %*ph\n",
729 msgs[i].addr, msgs[i].flags, msgs[i].len,
730 msgs[i].flags & I2C_M_RD ? 0 : msgs[i].len,
731 msgs[i].buf);
732
733 WARN_ON(i2c->msgs != NULL);
734 i2c->msgs = msgs;
735 i2c->num_msgs = num;
736
737 rc = mpc_i2c_execute_msg(i2c);
738 if (rc < 0)
739 ret = rc;
740
741 i2c->num_msgs = 0;
742 i2c->msgs = NULL;
743
744 return ret;
745}
746
747static u32 mpc_functionality(struct i2c_adapter *adap)
748{
749 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
750 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
751}
752
753static int fsl_i2c_bus_recovery(struct i2c_adapter *adap)
754{
755 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
756
757 if (i2c->has_errata_A004447)
758 mpc_i2c_fixup_A004447(i2c);
759 else
760 mpc_i2c_fixup(i2c);
761
762 return 0;
763}
764
765static const struct i2c_algorithm mpc_algo = {
766 .master_xfer = mpc_xfer,
767 .functionality = mpc_functionality,
768};
769
770static struct i2c_adapter mpc_ops = {
771 .owner = THIS_MODULE,
772 .algo = &mpc_algo,
773 .timeout = HZ,
774};
775
776static struct i2c_bus_recovery_info fsl_i2c_recovery_info = {
777 .recover_bus = fsl_i2c_bus_recovery,
778};
779
780static int fsl_i2c_probe(struct platform_device *op)
781{
782 const struct mpc_i2c_data *data;
783 struct mpc_i2c *i2c;
784 const u32 *prop;
785 u32 clock = MPC_I2C_CLOCK_LEGACY;
786 int result = 0;
787 int plen;
788 struct clk *clk;
789 int err;
790
791 i2c = devm_kzalloc(&op->dev, sizeof(*i2c), GFP_KERNEL);
792 if (!i2c)
793 return -ENOMEM;
794
795 i2c->dev = &op->dev; /* for debug and error output */
796
797 init_waitqueue_head(&i2c->waitq);
798 spin_lock_init(&i2c->lock);
799
800 i2c->base = devm_platform_ioremap_resource(op, 0);
801 if (IS_ERR(i2c->base))
802 return PTR_ERR(i2c->base);
803
804 i2c->irq = platform_get_irq(op, 0);
805 if (i2c->irq < 0)
806 return i2c->irq;
807
808 result = devm_request_irq(&op->dev, i2c->irq, mpc_i2c_isr,
809 IRQF_SHARED, "i2c-mpc", i2c);
810 if (result < 0) {
811 dev_err(i2c->dev, "failed to attach interrupt\n");
812 return result;
813 }
814
815 /*
816 * enable clock for the I2C peripheral (non fatal),
817 * keep a reference upon successful allocation
818 */
819 clk = devm_clk_get_optional(&op->dev, NULL);
820 if (IS_ERR(clk))
821 return PTR_ERR(clk);
822
823 err = clk_prepare_enable(clk);
824 if (err) {
825 dev_err(&op->dev, "failed to enable clock\n");
826 return err;
827 }
828
829 i2c->clk_per = clk;
830
831 if (of_property_read_bool(op->dev.of_node, "fsl,preserve-clocking")) {
832 clock = MPC_I2C_CLOCK_PRESERVE;
833 } else {
834 prop = of_get_property(op->dev.of_node, "clock-frequency",
835 &plen);
836 if (prop && plen == sizeof(u32))
837 clock = *prop;
838 }
839
840 data = device_get_match_data(&op->dev);
841 if (data) {
842 data->setup(op->dev.of_node, i2c, clock);
843 } else {
844 /* Backwards compatibility */
845 if (of_get_property(op->dev.of_node, "dfsrr", NULL))
846 mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock);
847 }
848
849 prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
850 if (prop && plen == sizeof(u32)) {
851 mpc_ops.timeout = *prop * HZ / 1000000;
852 if (mpc_ops.timeout < 5)
853 mpc_ops.timeout = 5;
854 }
855 dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
856
857 if (of_property_read_bool(op->dev.of_node, "fsl,i2c-erratum-a004447"))
858 i2c->has_errata_A004447 = true;
859
860 i2c->adap = mpc_ops;
861 scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
862 "MPC adapter (%s)", of_node_full_name(op->dev.of_node));
863 i2c->adap.dev.parent = &op->dev;
864 i2c->adap.nr = op->id;
865 i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
866 i2c->adap.bus_recovery_info = &fsl_i2c_recovery_info;
867 platform_set_drvdata(op, i2c);
868 i2c_set_adapdata(&i2c->adap, i2c);
869
870 result = i2c_add_numbered_adapter(&i2c->adap);
871 if (result)
872 goto fail_add;
873
874 return 0;
875
876 fail_add:
877 clk_disable_unprepare(i2c->clk_per);
878
879 return result;
880};
881
882static int fsl_i2c_remove(struct platform_device *op)
883{
884 struct mpc_i2c *i2c = platform_get_drvdata(op);
885
886 i2c_del_adapter(&i2c->adap);
887
888 clk_disable_unprepare(i2c->clk_per);
889
890 return 0;
891};
892
893static int __maybe_unused mpc_i2c_suspend(struct device *dev)
894{
895 struct mpc_i2c *i2c = dev_get_drvdata(dev);
896
897 i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
898 i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
899
900 return 0;
901}
902
903static int __maybe_unused mpc_i2c_resume(struct device *dev)
904{
905 struct mpc_i2c *i2c = dev_get_drvdata(dev);
906
907 writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
908 writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
909
910 return 0;
911}
912static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
913
914static const struct mpc_i2c_data mpc_i2c_data_512x = {
915 .setup = mpc_i2c_setup_512x,
916};
917
918static const struct mpc_i2c_data mpc_i2c_data_52xx = {
919 .setup = mpc_i2c_setup_52xx,
920};
921
922static const struct mpc_i2c_data mpc_i2c_data_8313 = {
923 .setup = mpc_i2c_setup_8xxx,
924};
925
926static const struct mpc_i2c_data mpc_i2c_data_8543 = {
927 .setup = mpc_i2c_setup_8xxx,
928};
929
930static const struct mpc_i2c_data mpc_i2c_data_8544 = {
931 .setup = mpc_i2c_setup_8xxx,
932};
933
934static const struct of_device_id mpc_i2c_of_match[] = {
935 {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
936 {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
937 {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
938 {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
939 {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
940 {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
941 {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
942 /* Backward compatibility */
943 {.compatible = "fsl-i2c", },
944 {},
945};
946MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
947
948/* Structure for a device driver */
949static struct platform_driver mpc_i2c_driver = {
950 .probe = fsl_i2c_probe,
951 .remove = fsl_i2c_remove,
952 .driver = {
953 .name = DRV_NAME,
954 .of_match_table = mpc_i2c_of_match,
955 .pm = &mpc_i2c_pm_ops,
956 },
957};
958
959module_platform_driver(mpc_i2c_driver);
960
961MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
962MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
963 "MPC824x/83xx/85xx/86xx/512x/52xx processors");
964MODULE_LICENSE("GPL");
1/*
2 * (C) Copyright 2003-2004
3 * Humboldt Solutions Ltd, adrian@humboldt.co.uk.
4
5 * This is a combined i2c adapter and algorithm driver for the
6 * MPC107/Tsi107 PowerPC northbridge and processors that include
7 * the same I2C unit (8240, 8245, 85xx).
8 *
9 * Release 0.8
10 *
11 * This file is licensed under the terms of the GNU General Public
12 * License version 2. This program is licensed "as is" without any
13 * warranty of any kind, whether express or implied.
14 */
15
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/sched.h>
19#include <linux/of_address.h>
20#include <linux/of_irq.h>
21#include <linux/of_platform.h>
22#include <linux/slab.h>
23
24#include <linux/clk.h>
25#include <linux/io.h>
26#include <linux/fsl_devices.h>
27#include <linux/i2c.h>
28#include <linux/interrupt.h>
29#include <linux/delay.h>
30
31#include <asm/mpc52xx.h>
32#include <sysdev/fsl_soc.h>
33
34#define DRV_NAME "mpc-i2c"
35
36#define MPC_I2C_CLOCK_LEGACY 0
37#define MPC_I2C_CLOCK_PRESERVE (~0U)
38
39#define MPC_I2C_FDR 0x04
40#define MPC_I2C_CR 0x08
41#define MPC_I2C_SR 0x0c
42#define MPC_I2C_DR 0x10
43#define MPC_I2C_DFSRR 0x14
44
45#define CCR_MEN 0x80
46#define CCR_MIEN 0x40
47#define CCR_MSTA 0x20
48#define CCR_MTX 0x10
49#define CCR_TXAK 0x08
50#define CCR_RSTA 0x04
51
52#define CSR_MCF 0x80
53#define CSR_MAAS 0x40
54#define CSR_MBB 0x20
55#define CSR_MAL 0x10
56#define CSR_SRW 0x04
57#define CSR_MIF 0x02
58#define CSR_RXAK 0x01
59
60struct mpc_i2c {
61 struct device *dev;
62 void __iomem *base;
63 u32 interrupt;
64 wait_queue_head_t queue;
65 struct i2c_adapter adap;
66 int irq;
67 u32 real_clk;
68#ifdef CONFIG_PM_SLEEP
69 u8 fdr, dfsrr;
70#endif
71 struct clk *clk_per;
72};
73
74struct mpc_i2c_divider {
75 u16 divider;
76 u16 fdr; /* including dfsrr */
77};
78
79struct mpc_i2c_data {
80 void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
81 u32 clock, u32 prescaler);
82 u32 prescaler;
83};
84
85static inline void writeccr(struct mpc_i2c *i2c, u32 x)
86{
87 writeb(x, i2c->base + MPC_I2C_CR);
88}
89
90static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
91{
92 struct mpc_i2c *i2c = dev_id;
93 if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
94 /* Read again to allow register to stabilise */
95 i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
96 writeb(0, i2c->base + MPC_I2C_SR);
97 wake_up(&i2c->queue);
98 }
99 return IRQ_HANDLED;
100}
101
102/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
103 * the bus, because it wants to send ACK.
104 * Following sequence of enabling/disabling and sending start/stop generates
105 * the 9 pulses, so it's all OK.
106 */
107static void mpc_i2c_fixup(struct mpc_i2c *i2c)
108{
109 int k;
110 u32 delay_val = 1000000 / i2c->real_clk + 1;
111
112 if (delay_val < 2)
113 delay_val = 2;
114
115 for (k = 9; k; k--) {
116 writeccr(i2c, 0);
117 writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
118 udelay(delay_val);
119 writeccr(i2c, CCR_MEN);
120 udelay(delay_val << 1);
121 }
122}
123
124static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
125{
126 unsigned long orig_jiffies = jiffies;
127 u32 x;
128 int result = 0;
129
130 if (!i2c->irq) {
131 while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
132 schedule();
133 if (time_after(jiffies, orig_jiffies + timeout)) {
134 dev_dbg(i2c->dev, "timeout\n");
135 writeccr(i2c, 0);
136 result = -EIO;
137 break;
138 }
139 }
140 x = readb(i2c->base + MPC_I2C_SR);
141 writeb(0, i2c->base + MPC_I2C_SR);
142 } else {
143 /* Interrupt mode */
144 result = wait_event_timeout(i2c->queue,
145 (i2c->interrupt & CSR_MIF), timeout);
146
147 if (unlikely(!(i2c->interrupt & CSR_MIF))) {
148 dev_dbg(i2c->dev, "wait timeout\n");
149 writeccr(i2c, 0);
150 result = -ETIMEDOUT;
151 }
152
153 x = i2c->interrupt;
154 i2c->interrupt = 0;
155 }
156
157 if (result < 0)
158 return result;
159
160 if (!(x & CSR_MCF)) {
161 dev_dbg(i2c->dev, "unfinished\n");
162 return -EIO;
163 }
164
165 if (x & CSR_MAL) {
166 dev_dbg(i2c->dev, "MAL\n");
167 return -EIO;
168 }
169
170 if (writing && (x & CSR_RXAK)) {
171 dev_dbg(i2c->dev, "No RXAK\n");
172 /* generate stop */
173 writeccr(i2c, CCR_MEN);
174 return -EIO;
175 }
176 return 0;
177}
178
179#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
180static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
181 {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
182 {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
183 {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
184 {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
185 {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
186 {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
187 {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
188 {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
189 {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
190 {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
191 {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
192 {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
193 {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
194 {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
195 {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
196 {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
197 {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
198 {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
199};
200
201static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
202 int prescaler, u32 *real_clk)
203{
204 const struct mpc_i2c_divider *div = NULL;
205 unsigned int pvr = mfspr(SPRN_PVR);
206 u32 divider;
207 int i;
208
209 if (clock == MPC_I2C_CLOCK_LEGACY) {
210 /* see below - default fdr = 0x3f -> div = 2048 */
211 *real_clk = mpc5xxx_get_bus_frequency(node) / 2048;
212 return -EINVAL;
213 }
214
215 /* Determine divider value */
216 divider = mpc5xxx_get_bus_frequency(node) / clock;
217
218 /*
219 * We want to choose an FDR/DFSR that generates an I2C bus speed that
220 * is equal to or lower than the requested speed.
221 */
222 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
223 div = &mpc_i2c_dividers_52xx[i];
224 /* Old MPC5200 rev A CPUs do not support the high bits */
225 if (div->fdr & 0xc0 && pvr == 0x80822011)
226 continue;
227 if (div->divider >= divider)
228 break;
229 }
230
231 *real_clk = mpc5xxx_get_bus_frequency(node) / div->divider;
232 return (int)div->fdr;
233}
234
235static void mpc_i2c_setup_52xx(struct device_node *node,
236 struct mpc_i2c *i2c,
237 u32 clock, u32 prescaler)
238{
239 int ret, fdr;
240
241 if (clock == MPC_I2C_CLOCK_PRESERVE) {
242 dev_dbg(i2c->dev, "using fdr %d\n",
243 readb(i2c->base + MPC_I2C_FDR));
244 return;
245 }
246
247 ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk);
248 fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
249
250 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
251
252 if (ret >= 0)
253 dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
254 fdr);
255}
256#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
257static void mpc_i2c_setup_52xx(struct device_node *node,
258 struct mpc_i2c *i2c,
259 u32 clock, u32 prescaler)
260{
261}
262#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
263
264#ifdef CONFIG_PPC_MPC512x
265static void mpc_i2c_setup_512x(struct device_node *node,
266 struct mpc_i2c *i2c,
267 u32 clock, u32 prescaler)
268{
269 struct device_node *node_ctrl;
270 void __iomem *ctrl;
271 const u32 *pval;
272 u32 idx;
273
274 /* Enable I2C interrupts for mpc5121 */
275 node_ctrl = of_find_compatible_node(NULL, NULL,
276 "fsl,mpc5121-i2c-ctrl");
277 if (node_ctrl) {
278 ctrl = of_iomap(node_ctrl, 0);
279 if (ctrl) {
280 /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
281 pval = of_get_property(node, "reg", NULL);
282 idx = (*pval & 0xff) / 0x20;
283 setbits32(ctrl, 1 << (24 + idx * 2));
284 iounmap(ctrl);
285 }
286 of_node_put(node_ctrl);
287 }
288
289 /* The clock setup for the 52xx works also fine for the 512x */
290 mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
291}
292#else /* CONFIG_PPC_MPC512x */
293static void mpc_i2c_setup_512x(struct device_node *node,
294 struct mpc_i2c *i2c,
295 u32 clock, u32 prescaler)
296{
297}
298#endif /* CONFIG_PPC_MPC512x */
299
300#ifdef CONFIG_FSL_SOC
301static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
302 {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
303 {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
304 {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
305 {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
306 {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
307 {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
308 {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
309 {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
310 {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
311 {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
312 {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
313 {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
314 {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
315 {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
316 {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
317 {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
318 {49152, 0x011e}, {61440, 0x011f}
319};
320
321static u32 mpc_i2c_get_sec_cfg_8xxx(void)
322{
323 struct device_node *node = NULL;
324 u32 __iomem *reg;
325 u32 val = 0;
326
327 node = of_find_node_by_name(NULL, "global-utilities");
328 if (node) {
329 const u32 *prop = of_get_property(node, "reg", NULL);
330 if (prop) {
331 /*
332 * Map and check POR Device Status Register 2
333 * (PORDEVSR2) at 0xE0014
334 */
335 reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
336 if (!reg)
337 printk(KERN_ERR
338 "Error: couldn't map PORDEVSR2\n");
339 else
340 val = in_be32(reg) & 0x00000080; /* sec-cfg */
341 iounmap(reg);
342 }
343 }
344 if (node)
345 of_node_put(node);
346
347 return val;
348}
349
350static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
351 u32 prescaler, u32 *real_clk)
352{
353 const struct mpc_i2c_divider *div = NULL;
354 u32 divider;
355 int i;
356
357 if (clock == MPC_I2C_CLOCK_LEGACY) {
358 /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
359 *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
360 return -EINVAL;
361 }
362
363 /* Determine proper divider value */
364 if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
365 prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
366 if (!prescaler)
367 prescaler = 1;
368
369 divider = fsl_get_sys_freq() / clock / prescaler;
370
371 pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
372 fsl_get_sys_freq(), clock, divider);
373
374 /*
375 * We want to choose an FDR/DFSR that generates an I2C bus speed that
376 * is equal to or lower than the requested speed.
377 */
378 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
379 div = &mpc_i2c_dividers_8xxx[i];
380 if (div->divider >= divider)
381 break;
382 }
383
384 *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
385 return div ? (int)div->fdr : -EINVAL;
386}
387
388static void mpc_i2c_setup_8xxx(struct device_node *node,
389 struct mpc_i2c *i2c,
390 u32 clock, u32 prescaler)
391{
392 int ret, fdr;
393
394 if (clock == MPC_I2C_CLOCK_PRESERVE) {
395 dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
396 readb(i2c->base + MPC_I2C_DFSRR),
397 readb(i2c->base + MPC_I2C_FDR));
398 return;
399 }
400
401 ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk);
402 fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
403
404 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
405 writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
406
407 if (ret >= 0)
408 dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
409 i2c->real_clk, fdr >> 8, fdr & 0xff);
410}
411
412#else /* !CONFIG_FSL_SOC */
413static void mpc_i2c_setup_8xxx(struct device_node *node,
414 struct mpc_i2c *i2c,
415 u32 clock, u32 prescaler)
416{
417}
418#endif /* CONFIG_FSL_SOC */
419
420static void mpc_i2c_start(struct mpc_i2c *i2c)
421{
422 /* Clear arbitration */
423 writeb(0, i2c->base + MPC_I2C_SR);
424 /* Start with MEN */
425 writeccr(i2c, CCR_MEN);
426}
427
428static void mpc_i2c_stop(struct mpc_i2c *i2c)
429{
430 writeccr(i2c, CCR_MEN);
431}
432
433static int mpc_write(struct mpc_i2c *i2c, int target,
434 const u8 *data, int length, int restart)
435{
436 int i, result;
437 unsigned timeout = i2c->adap.timeout;
438 u32 flags = restart ? CCR_RSTA : 0;
439
440 /* Start as master */
441 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
442 /* Write target byte */
443 writeb((target << 1), i2c->base + MPC_I2C_DR);
444
445 result = i2c_wait(i2c, timeout, 1);
446 if (result < 0)
447 return result;
448
449 for (i = 0; i < length; i++) {
450 /* Write data byte */
451 writeb(data[i], i2c->base + MPC_I2C_DR);
452
453 result = i2c_wait(i2c, timeout, 1);
454 if (result < 0)
455 return result;
456 }
457
458 return 0;
459}
460
461static int mpc_read(struct mpc_i2c *i2c, int target,
462 u8 *data, int length, int restart, bool recv_len)
463{
464 unsigned timeout = i2c->adap.timeout;
465 int i, result;
466 u32 flags = restart ? CCR_RSTA : 0;
467
468 /* Switch to read - restart */
469 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
470 /* Write target address byte - this time with the read flag set */
471 writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
472
473 result = i2c_wait(i2c, timeout, 1);
474 if (result < 0)
475 return result;
476
477 if (length) {
478 if (length == 1 && !recv_len)
479 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
480 else
481 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
482 /* Dummy read */
483 readb(i2c->base + MPC_I2C_DR);
484 }
485
486 for (i = 0; i < length; i++) {
487 u8 byte;
488
489 result = i2c_wait(i2c, timeout, 0);
490 if (result < 0)
491 return result;
492
493 /*
494 * For block reads, we have to know the total length (1st byte)
495 * before we can determine if we are done.
496 */
497 if (i || !recv_len) {
498 /* Generate txack on next to last byte */
499 if (i == length - 2)
500 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
501 | CCR_TXAK);
502 /* Do not generate stop on last byte */
503 if (i == length - 1)
504 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
505 | CCR_MTX);
506 }
507
508 byte = readb(i2c->base + MPC_I2C_DR);
509
510 /*
511 * Adjust length if first received byte is length.
512 * The length is 1 length byte plus actually data length
513 */
514 if (i == 0 && recv_len) {
515 if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
516 return -EPROTO;
517 length += byte;
518 /*
519 * For block reads, generate txack here if data length
520 * is 1 byte (total length is 2 bytes).
521 */
522 if (length == 2)
523 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
524 | CCR_TXAK);
525 }
526 data[i] = byte;
527 }
528
529 return length;
530}
531
532static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
533{
534 struct i2c_msg *pmsg;
535 int i;
536 int ret = 0;
537 unsigned long orig_jiffies = jiffies;
538 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
539
540 mpc_i2c_start(i2c);
541
542 /* Allow bus up to 1s to become not busy */
543 while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
544 if (signal_pending(current)) {
545 dev_dbg(i2c->dev, "Interrupted\n");
546 writeccr(i2c, 0);
547 return -EINTR;
548 }
549 if (time_after(jiffies, orig_jiffies + HZ)) {
550 u8 status = readb(i2c->base + MPC_I2C_SR);
551
552 dev_dbg(i2c->dev, "timeout\n");
553 if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
554 writeb(status & ~CSR_MAL,
555 i2c->base + MPC_I2C_SR);
556 mpc_i2c_fixup(i2c);
557 }
558 return -EIO;
559 }
560 schedule();
561 }
562
563 for (i = 0; ret >= 0 && i < num; i++) {
564 pmsg = &msgs[i];
565 dev_dbg(i2c->dev,
566 "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
567 pmsg->flags & I2C_M_RD ? "read" : "write",
568 pmsg->len, pmsg->addr, i + 1, num);
569 if (pmsg->flags & I2C_M_RD) {
570 bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
571
572 ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
573 recv_len);
574 if (recv_len && ret > 0)
575 pmsg->len = ret;
576 } else {
577 ret =
578 mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
579 }
580 }
581 mpc_i2c_stop(i2c); /* Initiate STOP */
582 orig_jiffies = jiffies;
583 /* Wait until STOP is seen, allow up to 1 s */
584 while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
585 if (time_after(jiffies, orig_jiffies + HZ)) {
586 u8 status = readb(i2c->base + MPC_I2C_SR);
587
588 dev_dbg(i2c->dev, "timeout\n");
589 if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
590 writeb(status & ~CSR_MAL,
591 i2c->base + MPC_I2C_SR);
592 mpc_i2c_fixup(i2c);
593 }
594 return -EIO;
595 }
596 cond_resched();
597 }
598 return (ret < 0) ? ret : num;
599}
600
601static u32 mpc_functionality(struct i2c_adapter *adap)
602{
603 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
604 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
605}
606
607static const struct i2c_algorithm mpc_algo = {
608 .master_xfer = mpc_xfer,
609 .functionality = mpc_functionality,
610};
611
612static struct i2c_adapter mpc_ops = {
613 .owner = THIS_MODULE,
614 .algo = &mpc_algo,
615 .timeout = HZ,
616};
617
618static const struct of_device_id mpc_i2c_of_match[];
619static int fsl_i2c_probe(struct platform_device *op)
620{
621 const struct of_device_id *match;
622 struct mpc_i2c *i2c;
623 const u32 *prop;
624 u32 clock = MPC_I2C_CLOCK_LEGACY;
625 int result = 0;
626 int plen;
627 struct resource res;
628 struct clk *clk;
629 int err;
630
631 match = of_match_device(mpc_i2c_of_match, &op->dev);
632 if (!match)
633 return -EINVAL;
634
635 i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
636 if (!i2c)
637 return -ENOMEM;
638
639 i2c->dev = &op->dev; /* for debug and error output */
640
641 init_waitqueue_head(&i2c->queue);
642
643 i2c->base = of_iomap(op->dev.of_node, 0);
644 if (!i2c->base) {
645 dev_err(i2c->dev, "failed to map controller\n");
646 result = -ENOMEM;
647 goto fail_map;
648 }
649
650 i2c->irq = irq_of_parse_and_map(op->dev.of_node, 0);
651 if (i2c->irq) { /* no i2c->irq implies polling */
652 result = request_irq(i2c->irq, mpc_i2c_isr,
653 IRQF_SHARED, "i2c-mpc", i2c);
654 if (result < 0) {
655 dev_err(i2c->dev, "failed to attach interrupt\n");
656 goto fail_request;
657 }
658 }
659
660 /*
661 * enable clock for the I2C peripheral (non fatal),
662 * keep a reference upon successful allocation
663 */
664 clk = devm_clk_get(&op->dev, NULL);
665 if (!IS_ERR(clk)) {
666 err = clk_prepare_enable(clk);
667 if (err) {
668 dev_err(&op->dev, "failed to enable clock\n");
669 goto fail_request;
670 } else {
671 i2c->clk_per = clk;
672 }
673 }
674
675 if (of_get_property(op->dev.of_node, "fsl,preserve-clocking", NULL)) {
676 clock = MPC_I2C_CLOCK_PRESERVE;
677 } else {
678 prop = of_get_property(op->dev.of_node, "clock-frequency",
679 &plen);
680 if (prop && plen == sizeof(u32))
681 clock = *prop;
682 }
683
684 if (match->data) {
685 const struct mpc_i2c_data *data = match->data;
686 data->setup(op->dev.of_node, i2c, clock, data->prescaler);
687 } else {
688 /* Backwards compatibility */
689 if (of_get_property(op->dev.of_node, "dfsrr", NULL))
690 mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0);
691 }
692
693 prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
694 if (prop && plen == sizeof(u32)) {
695 mpc_ops.timeout = *prop * HZ / 1000000;
696 if (mpc_ops.timeout < 5)
697 mpc_ops.timeout = 5;
698 }
699 dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
700
701 platform_set_drvdata(op, i2c);
702
703 i2c->adap = mpc_ops;
704 of_address_to_resource(op->dev.of_node, 0, &res);
705 scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
706 "MPC adapter at 0x%llx", (unsigned long long)res.start);
707 i2c_set_adapdata(&i2c->adap, i2c);
708 i2c->adap.dev.parent = &op->dev;
709 i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
710
711 result = i2c_add_adapter(&i2c->adap);
712 if (result < 0) {
713 dev_err(i2c->dev, "failed to add adapter\n");
714 goto fail_add;
715 }
716
717 return result;
718
719 fail_add:
720 if (i2c->clk_per)
721 clk_disable_unprepare(i2c->clk_per);
722 free_irq(i2c->irq, i2c);
723 fail_request:
724 irq_dispose_mapping(i2c->irq);
725 iounmap(i2c->base);
726 fail_map:
727 kfree(i2c);
728 return result;
729};
730
731static int fsl_i2c_remove(struct platform_device *op)
732{
733 struct mpc_i2c *i2c = platform_get_drvdata(op);
734
735 i2c_del_adapter(&i2c->adap);
736
737 if (i2c->clk_per)
738 clk_disable_unprepare(i2c->clk_per);
739
740 if (i2c->irq)
741 free_irq(i2c->irq, i2c);
742
743 irq_dispose_mapping(i2c->irq);
744 iounmap(i2c->base);
745 kfree(i2c);
746 return 0;
747};
748
749#ifdef CONFIG_PM_SLEEP
750static int mpc_i2c_suspend(struct device *dev)
751{
752 struct mpc_i2c *i2c = dev_get_drvdata(dev);
753
754 i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
755 i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
756
757 return 0;
758}
759
760static int mpc_i2c_resume(struct device *dev)
761{
762 struct mpc_i2c *i2c = dev_get_drvdata(dev);
763
764 writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
765 writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
766
767 return 0;
768}
769
770static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
771#define MPC_I2C_PM_OPS (&mpc_i2c_pm_ops)
772#else
773#define MPC_I2C_PM_OPS NULL
774#endif
775
776static const struct mpc_i2c_data mpc_i2c_data_512x = {
777 .setup = mpc_i2c_setup_512x,
778};
779
780static const struct mpc_i2c_data mpc_i2c_data_52xx = {
781 .setup = mpc_i2c_setup_52xx,
782};
783
784static const struct mpc_i2c_data mpc_i2c_data_8313 = {
785 .setup = mpc_i2c_setup_8xxx,
786};
787
788static const struct mpc_i2c_data mpc_i2c_data_8543 = {
789 .setup = mpc_i2c_setup_8xxx,
790 .prescaler = 2,
791};
792
793static const struct mpc_i2c_data mpc_i2c_data_8544 = {
794 .setup = mpc_i2c_setup_8xxx,
795 .prescaler = 3,
796};
797
798static const struct of_device_id mpc_i2c_of_match[] = {
799 {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
800 {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
801 {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
802 {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
803 {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
804 {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
805 {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
806 /* Backward compatibility */
807 {.compatible = "fsl-i2c", },
808 {},
809};
810MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
811
812/* Structure for a device driver */
813static struct platform_driver mpc_i2c_driver = {
814 .probe = fsl_i2c_probe,
815 .remove = fsl_i2c_remove,
816 .driver = {
817 .owner = THIS_MODULE,
818 .name = DRV_NAME,
819 .of_match_table = mpc_i2c_of_match,
820 .pm = MPC_I2C_PM_OPS,
821 },
822};
823
824module_platform_driver(mpc_i2c_driver);
825
826MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
827MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
828 "MPC824x/83xx/85xx/86xx/512x/52xx processors");
829MODULE_LICENSE("GPL");