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 DRV_NAME "mpc-i2c"
34
35 #define MPC_I2C_CLOCK_LEGACY 0
36 #define MPC_I2C_CLOCK_PRESERVE (~0U)
37
38 #define MPC_I2C_FDR 0x04
39 #define MPC_I2C_CR 0x08
40 #define MPC_I2C_SR 0x0c
41 #define MPC_I2C_DR 0x10
42 #define MPC_I2C_DFSRR 0x14
43
44 #define CCR_MEN 0x80
45 #define CCR_MIEN 0x40
46 #define CCR_MSTA 0x20
47 #define CCR_MTX 0x10
48 #define CCR_TXAK 0x08
49 #define CCR_RSTA 0x04
50 #define CCR_RSVD 0x02
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
60 enum mpc_i2c_action {
61 MPC_I2C_ACTION_START = 1,
62 MPC_I2C_ACTION_RESTART,
63 MPC_I2C_ACTION_READ_BEGIN,
64 MPC_I2C_ACTION_READ_BYTE,
65 MPC_I2C_ACTION_WRITE,
66 MPC_I2C_ACTION_STOP,
67
68 __MPC_I2C_ACTION_CNT
69 };
70
71 static const char * const action_str[] = {
72 "invalid",
73 "start",
74 "restart",
75 "read begin",
76 "read",
77 "write",
78 "stop",
79 };
80
81 static_assert(ARRAY_SIZE(action_str) == __MPC_I2C_ACTION_CNT);
82
83 struct mpc_i2c {
84 struct device *dev;
85 void __iomem *base;
86 u32 interrupt;
87 wait_queue_head_t waitq;
88 spinlock_t lock;
89 struct i2c_adapter adap;
90 int irq;
91 u32 real_clk;
92 u8 fdr, dfsrr;
93 struct clk *clk_per;
94 u32 cntl_bits;
95 enum mpc_i2c_action action;
96 struct i2c_msg *msgs;
97 int num_msgs;
98 int curr_msg;
99 u32 byte_posn;
100 u32 block;
101 int rc;
102 int expect_rxack;
103 bool has_errata_A004447;
104 };
105
106 struct mpc_i2c_divider {
107 u16 divider;
108 u16 fdr; /* including dfsrr */
109 };
110
111 struct mpc_i2c_data {
112 void (*setup)(struct device_node *node, struct mpc_i2c *i2c, u32 clock);
113 };
114
writeccr(struct mpc_i2c * i2c,u32 x)115 static inline void writeccr(struct mpc_i2c *i2c, u32 x)
116 {
117 writeb(x, i2c->base + MPC_I2C_CR);
118 }
119
120 /* Sometimes 9th clock pulse isn't generated, and slave doesn't release
121 * the bus, because it wants to send ACK.
122 * Following sequence of enabling/disabling and sending start/stop generates
123 * the 9 pulses, each with a START then ending with STOP, so it's all OK.
124 */
mpc_i2c_fixup(struct mpc_i2c * i2c)125 static void mpc_i2c_fixup(struct mpc_i2c *i2c)
126 {
127 int k;
128 unsigned long flags;
129
130 for (k = 9; k; k--) {
131 writeccr(i2c, 0);
132 writeb(0, i2c->base + MPC_I2C_SR); /* clear any status bits */
133 writeccr(i2c, CCR_MEN | CCR_MSTA); /* START */
134 readb(i2c->base + MPC_I2C_DR); /* init xfer */
135 udelay(15); /* let it hit the bus */
136 local_irq_save(flags); /* should not be delayed further */
137 writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSTA); /* delay SDA */
138 readb(i2c->base + MPC_I2C_DR);
139 if (k != 1)
140 udelay(5);
141 local_irq_restore(flags);
142 }
143 writeccr(i2c, CCR_MEN); /* Initiate STOP */
144 readb(i2c->base + MPC_I2C_DR);
145 udelay(15); /* Let STOP propagate */
146 writeccr(i2c, 0);
147 }
148
i2c_mpc_wait_sr(struct mpc_i2c * i2c,int mask)149 static int i2c_mpc_wait_sr(struct mpc_i2c *i2c, int mask)
150 {
151 void __iomem *addr = i2c->base + MPC_I2C_SR;
152 u8 val;
153
154 return readb_poll_timeout(addr, val, val & mask, 0, 100);
155 }
156
157 /*
158 * Workaround for Erratum A004447. From the P2040CE Rev Q
159 *
160 * 1. Set up the frequency divider and sampling rate.
161 * 2. I2CCR - a0h
162 * 3. Poll for I2CSR[MBB] to get set.
163 * 4. If I2CSR[MAL] is set (an indication that SDA is stuck low), then go to
164 * step 5. If MAL is not set, then go to step 13.
165 * 5. I2CCR - 00h
166 * 6. I2CCR - 22h
167 * 7. I2CCR - a2h
168 * 8. Poll for I2CSR[MBB] to get set.
169 * 9. Issue read to I2CDR.
170 * 10. Poll for I2CSR[MIF] to be set.
171 * 11. I2CCR - 82h
172 * 12. Workaround complete. Skip the next steps.
173 * 13. Issue read to I2CDR.
174 * 14. Poll for I2CSR[MIF] to be set.
175 * 15. I2CCR - 80h
176 */
mpc_i2c_fixup_A004447(struct mpc_i2c * i2c)177 static void mpc_i2c_fixup_A004447(struct mpc_i2c *i2c)
178 {
179 int ret;
180 u32 val;
181
182 writeccr(i2c, CCR_MEN | CCR_MSTA);
183 ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
184 if (ret) {
185 dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
186 return;
187 }
188
189 val = readb(i2c->base + MPC_I2C_SR);
190
191 if (val & CSR_MAL) {
192 writeccr(i2c, 0x00);
193 writeccr(i2c, CCR_MSTA | CCR_RSVD);
194 writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSVD);
195 ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
196 if (ret) {
197 dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
198 return;
199 }
200 val = readb(i2c->base + MPC_I2C_DR);
201 ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
202 if (ret) {
203 dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
204 return;
205 }
206 writeccr(i2c, CCR_MEN | CCR_RSVD);
207 } else {
208 val = readb(i2c->base + MPC_I2C_DR);
209 ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
210 if (ret) {
211 dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
212 return;
213 }
214 writeccr(i2c, CCR_MEN);
215 }
216 }
217
218 #if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
219 static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
220 {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
221 {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
222 {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
223 {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
224 {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
225 {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
226 {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
227 {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
228 {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
229 {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
230 {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
231 {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
232 {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
233 {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
234 {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
235 {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
236 {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
237 {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
238 };
239
mpc_i2c_get_fdr_52xx(struct device_node * node,u32 clock,u32 * real_clk)240 static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
241 u32 *real_clk)
242 {
243 struct fwnode_handle *fwnode = of_fwnode_handle(node);
244 const struct mpc_i2c_divider *div = NULL;
245 unsigned int pvr = mfspr(SPRN_PVR);
246 u32 divider;
247 int i;
248
249 if (clock == MPC_I2C_CLOCK_LEGACY) {
250 /* see below - default fdr = 0x3f -> div = 2048 */
251 *real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / 2048;
252 return -EINVAL;
253 }
254
255 /* Determine divider value */
256 divider = mpc5xxx_fwnode_get_bus_frequency(fwnode) / clock;
257
258 /*
259 * We want to choose an FDR/DFSR that generates an I2C bus speed that
260 * is equal to or lower than the requested speed.
261 */
262 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
263 div = &mpc_i2c_dividers_52xx[i];
264 /* Old MPC5200 rev A CPUs do not support the high bits */
265 if (div->fdr & 0xc0 && pvr == 0x80822011)
266 continue;
267 if (div->divider >= divider)
268 break;
269 }
270
271 *real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / div->divider;
272 return (int)div->fdr;
273 }
274
mpc_i2c_setup_52xx(struct device_node * node,struct mpc_i2c * i2c,u32 clock)275 static void mpc_i2c_setup_52xx(struct device_node *node,
276 struct mpc_i2c *i2c,
277 u32 clock)
278 {
279 int ret, fdr;
280
281 if (clock == MPC_I2C_CLOCK_PRESERVE) {
282 dev_dbg(i2c->dev, "using fdr %d\n",
283 readb(i2c->base + MPC_I2C_FDR));
284 return;
285 }
286
287 ret = mpc_i2c_get_fdr_52xx(node, clock, &i2c->real_clk);
288 fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
289
290 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
291
292 if (ret >= 0)
293 dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
294 fdr);
295 }
296 #else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
mpc_i2c_setup_52xx(struct device_node * node,struct mpc_i2c * i2c,u32 clock)297 static void mpc_i2c_setup_52xx(struct device_node *node,
298 struct mpc_i2c *i2c,
299 u32 clock)
300 {
301 }
302 #endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
303
304 #ifdef CONFIG_PPC_MPC512x
mpc_i2c_setup_512x(struct device_node * node,struct mpc_i2c * i2c,u32 clock)305 static void mpc_i2c_setup_512x(struct device_node *node,
306 struct mpc_i2c *i2c,
307 u32 clock)
308 {
309 struct device_node *node_ctrl;
310 void __iomem *ctrl;
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 u64 addr;
320 /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
321 of_property_read_reg(node, 0, &addr, NULL);
322 idx = (addr & 0xff) / 0x20;
323 setbits32(ctrl, 1 << (24 + idx * 2));
324 iounmap(ctrl);
325 }
326 of_node_put(node_ctrl);
327 }
328
329 /* The clock setup for the 52xx works also fine for the 512x */
330 mpc_i2c_setup_52xx(node, i2c, clock);
331 }
332 #else /* CONFIG_PPC_MPC512x */
mpc_i2c_setup_512x(struct device_node * node,struct mpc_i2c * i2c,u32 clock)333 static void mpc_i2c_setup_512x(struct device_node *node,
334 struct mpc_i2c *i2c,
335 u32 clock)
336 {
337 }
338 #endif /* CONFIG_PPC_MPC512x */
339
340 #ifdef CONFIG_FSL_SOC
341 static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
342 {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
343 {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
344 {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
345 {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
346 {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
347 {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
348 {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
349 {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
350 {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
351 {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
352 {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
353 {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
354 {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
355 {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
356 {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
357 {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
358 {49152, 0x011e}, {61440, 0x011f}
359 };
360
mpc_i2c_get_sec_cfg_8xxx(void)361 static u32 mpc_i2c_get_sec_cfg_8xxx(void)
362 {
363 struct device_node *node;
364 u32 __iomem *reg;
365 u32 val = 0;
366
367 node = of_find_node_by_name(NULL, "global-utilities");
368 if (node) {
369 const u32 *prop = of_get_property(node, "reg", NULL);
370 if (prop) {
371 /*
372 * Map and check POR Device Status Register 2
373 * (PORDEVSR2) at 0xE0014. Note than while MPC8533
374 * and MPC8544 indicate SEC frequency ratio
375 * configuration as bit 26 in PORDEVSR2, other MPC8xxx
376 * parts may store it differently or may not have it
377 * at all.
378 */
379 reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
380 if (!reg)
381 printk(KERN_ERR
382 "Error: couldn't map PORDEVSR2\n");
383 else
384 val = in_be32(reg) & 0x00000020; /* sec-cfg */
385 iounmap(reg);
386 }
387 }
388 of_node_put(node);
389
390 return val;
391 }
392
mpc_i2c_get_prescaler_8xxx(void)393 static u32 mpc_i2c_get_prescaler_8xxx(void)
394 {
395 /*
396 * According to the AN2919 all MPC824x have prescaler 1, while MPC83xx
397 * may have prescaler 1, 2, or 3, depending on the power-on
398 * configuration.
399 */
400 u32 prescaler = 1;
401
402 /* mpc85xx */
403 if (pvr_version_is(PVR_VER_E500V1) || pvr_version_is(PVR_VER_E500V2)
404 || pvr_version_is(PVR_VER_E500MC)
405 || pvr_version_is(PVR_VER_E5500)
406 || pvr_version_is(PVR_VER_E6500)) {
407 unsigned int svr = mfspr(SPRN_SVR);
408
409 if ((SVR_SOC_VER(svr) == SVR_8540)
410 || (SVR_SOC_VER(svr) == SVR_8541)
411 || (SVR_SOC_VER(svr) == SVR_8560)
412 || (SVR_SOC_VER(svr) == SVR_8555)
413 || (SVR_SOC_VER(svr) == SVR_8610))
414 /* the above 85xx SoCs have prescaler 1 */
415 prescaler = 1;
416 else if ((SVR_SOC_VER(svr) == SVR_8533)
417 || (SVR_SOC_VER(svr) == SVR_8544))
418 /* the above 85xx SoCs have prescaler 3 or 2 */
419 prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
420 else
421 /* all the other 85xx have prescaler 2 */
422 prescaler = 2;
423 }
424
425 return prescaler;
426 }
427
mpc_i2c_get_fdr_8xxx(struct device_node * node,u32 clock,u32 * real_clk)428 static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
429 u32 *real_clk)
430 {
431 const struct mpc_i2c_divider *div = NULL;
432 u32 prescaler = mpc_i2c_get_prescaler_8xxx();
433 u32 divider;
434 int i;
435
436 if (clock == MPC_I2C_CLOCK_LEGACY) {
437 /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
438 *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
439 return -EINVAL;
440 }
441
442 divider = fsl_get_sys_freq() / clock / prescaler;
443
444 pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
445 fsl_get_sys_freq(), clock, divider);
446
447 /*
448 * We want to choose an FDR/DFSR that generates an I2C bus speed that
449 * is equal to or lower than the requested speed.
450 */
451 for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
452 div = &mpc_i2c_dividers_8xxx[i];
453 if (div->divider >= divider)
454 break;
455 }
456
457 *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
458 return (int)div->fdr;
459 }
460
mpc_i2c_setup_8xxx(struct device_node * node,struct mpc_i2c * i2c,u32 clock)461 static void mpc_i2c_setup_8xxx(struct device_node *node,
462 struct mpc_i2c *i2c,
463 u32 clock)
464 {
465 int ret, fdr;
466
467 if (clock == MPC_I2C_CLOCK_PRESERVE) {
468 dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
469 readb(i2c->base + MPC_I2C_DFSRR),
470 readb(i2c->base + MPC_I2C_FDR));
471 return;
472 }
473
474 ret = mpc_i2c_get_fdr_8xxx(node, clock, &i2c->real_clk);
475 fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
476
477 writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
478 writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
479
480 if (ret >= 0)
481 dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
482 i2c->real_clk, fdr >> 8, fdr & 0xff);
483 }
484
485 #else /* !CONFIG_FSL_SOC */
mpc_i2c_setup_8xxx(struct device_node * node,struct mpc_i2c * i2c,u32 clock)486 static void mpc_i2c_setup_8xxx(struct device_node *node,
487 struct mpc_i2c *i2c,
488 u32 clock)
489 {
490 }
491 #endif /* CONFIG_FSL_SOC */
492
mpc_i2c_finish(struct mpc_i2c * i2c,int rc)493 static void mpc_i2c_finish(struct mpc_i2c *i2c, int rc)
494 {
495 i2c->rc = rc;
496 i2c->block = 0;
497 i2c->cntl_bits = CCR_MEN;
498 writeccr(i2c, i2c->cntl_bits);
499 wake_up(&i2c->waitq);
500 }
501
mpc_i2c_do_action(struct mpc_i2c * i2c)502 static void mpc_i2c_do_action(struct mpc_i2c *i2c)
503 {
504 struct i2c_msg *msg = NULL;
505 int dir = 0;
506 int recv_len = 0;
507 u8 byte;
508
509 dev_dbg(i2c->dev, "action = %s\n", action_str[i2c->action]);
510
511 i2c->cntl_bits &= ~(CCR_RSTA | CCR_MTX | CCR_TXAK);
512
513 if (i2c->action != MPC_I2C_ACTION_STOP) {
514 msg = &i2c->msgs[i2c->curr_msg];
515 if (msg->flags & I2C_M_RD)
516 dir = 1;
517 if (msg->flags & I2C_M_RECV_LEN)
518 recv_len = 1;
519 }
520
521 switch (i2c->action) {
522 case MPC_I2C_ACTION_RESTART:
523 i2c->cntl_bits |= CCR_RSTA;
524 fallthrough;
525
526 case MPC_I2C_ACTION_START:
527 i2c->cntl_bits |= CCR_MSTA | CCR_MTX;
528 writeccr(i2c, i2c->cntl_bits);
529 writeb((msg->addr << 1) | dir, i2c->base + MPC_I2C_DR);
530 i2c->expect_rxack = 1;
531 i2c->action = dir ? MPC_I2C_ACTION_READ_BEGIN : MPC_I2C_ACTION_WRITE;
532 break;
533
534 case MPC_I2C_ACTION_READ_BEGIN:
535 if (msg->len) {
536 if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN))
537 i2c->cntl_bits |= CCR_TXAK;
538
539 writeccr(i2c, i2c->cntl_bits);
540 /* Dummy read */
541 readb(i2c->base + MPC_I2C_DR);
542 }
543 i2c->action = MPC_I2C_ACTION_READ_BYTE;
544 break;
545
546 case MPC_I2C_ACTION_READ_BYTE:
547 if (i2c->byte_posn || !recv_len) {
548 /* Generate Tx ACK on next to last byte */
549 if (i2c->byte_posn == msg->len - 2)
550 i2c->cntl_bits |= CCR_TXAK;
551 /* Do not generate stop on last byte */
552 if (i2c->byte_posn == msg->len - 1)
553 i2c->cntl_bits |= CCR_MTX;
554
555 writeccr(i2c, i2c->cntl_bits);
556 }
557
558 byte = readb(i2c->base + MPC_I2C_DR);
559
560 if (i2c->byte_posn == 0 && recv_len) {
561 if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX) {
562 mpc_i2c_finish(i2c, -EPROTO);
563 return;
564 }
565 msg->len += byte;
566 /*
567 * For block reads, generate Tx ACK here if data length
568 * is 1 byte (total length is 2 bytes).
569 */
570 if (msg->len == 2) {
571 i2c->cntl_bits |= CCR_TXAK;
572 writeccr(i2c, i2c->cntl_bits);
573 }
574 }
575
576 dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action], byte);
577 msg->buf[i2c->byte_posn++] = byte;
578 break;
579
580 case MPC_I2C_ACTION_WRITE:
581 dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action],
582 msg->buf[i2c->byte_posn]);
583 writeb(msg->buf[i2c->byte_posn++], i2c->base + MPC_I2C_DR);
584 i2c->expect_rxack = 1;
585 break;
586
587 case MPC_I2C_ACTION_STOP:
588 mpc_i2c_finish(i2c, 0);
589 break;
590
591 default:
592 WARN(1, "Unexpected action %d\n", i2c->action);
593 break;
594 }
595
596 if (msg && msg->len == i2c->byte_posn) {
597 i2c->curr_msg++;
598 i2c->byte_posn = 0;
599
600 if (i2c->curr_msg == i2c->num_msgs) {
601 i2c->action = MPC_I2C_ACTION_STOP;
602 /*
603 * We don't get another interrupt on read so
604 * finish the transfer now
605 */
606 if (dir)
607 mpc_i2c_finish(i2c, 0);
608 } else {
609 i2c->action = MPC_I2C_ACTION_RESTART;
610 }
611 }
612 }
613
mpc_i2c_do_intr(struct mpc_i2c * i2c,u8 status)614 static void mpc_i2c_do_intr(struct mpc_i2c *i2c, u8 status)
615 {
616 spin_lock(&i2c->lock);
617
618 if (!(status & CSR_MCF)) {
619 dev_dbg(i2c->dev, "unfinished\n");
620 mpc_i2c_finish(i2c, -EIO);
621 goto out;
622 }
623
624 if (status & CSR_MAL) {
625 dev_dbg(i2c->dev, "arbitration lost\n");
626 mpc_i2c_finish(i2c, -EAGAIN);
627 goto out;
628 }
629
630 if (i2c->expect_rxack && (status & CSR_RXAK)) {
631 dev_dbg(i2c->dev, "no Rx ACK\n");
632 mpc_i2c_finish(i2c, -ENXIO);
633 goto out;
634 }
635 i2c->expect_rxack = 0;
636
637 mpc_i2c_do_action(i2c);
638
639 out:
640 spin_unlock(&i2c->lock);
641 }
642
mpc_i2c_isr(int irq,void * dev_id)643 static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
644 {
645 struct mpc_i2c *i2c = dev_id;
646 u8 status;
647
648 status = readb(i2c->base + MPC_I2C_SR);
649 if (status & CSR_MIF) {
650 /* Wait up to 100us for transfer to properly complete */
651 readb_poll_timeout_atomic(i2c->base + MPC_I2C_SR, status, status & CSR_MCF, 0, 100);
652 writeb(0, i2c->base + MPC_I2C_SR);
653 mpc_i2c_do_intr(i2c, status);
654 return IRQ_HANDLED;
655 }
656 return IRQ_NONE;
657 }
658
mpc_i2c_wait_for_completion(struct mpc_i2c * i2c)659 static int mpc_i2c_wait_for_completion(struct mpc_i2c *i2c)
660 {
661 long time_left;
662
663 time_left = wait_event_timeout(i2c->waitq, !i2c->block, i2c->adap.timeout);
664 if (!time_left)
665 return -ETIMEDOUT;
666 if (time_left < 0)
667 return time_left;
668
669 return 0;
670 }
671
mpc_i2c_execute_msg(struct mpc_i2c * i2c)672 static int mpc_i2c_execute_msg(struct mpc_i2c *i2c)
673 {
674 unsigned long orig_jiffies;
675 unsigned long flags;
676 int ret;
677
678 spin_lock_irqsave(&i2c->lock, flags);
679
680 i2c->curr_msg = 0;
681 i2c->rc = 0;
682 i2c->byte_posn = 0;
683 i2c->block = 1;
684 i2c->action = MPC_I2C_ACTION_START;
685
686 i2c->cntl_bits = CCR_MEN | CCR_MIEN;
687 writeb(0, i2c->base + MPC_I2C_SR);
688 writeccr(i2c, i2c->cntl_bits);
689
690 mpc_i2c_do_action(i2c);
691
692 spin_unlock_irqrestore(&i2c->lock, flags);
693
694 ret = mpc_i2c_wait_for_completion(i2c);
695 if (ret)
696 i2c->rc = ret;
697
698 if (i2c->rc == -EIO || i2c->rc == -EAGAIN || i2c->rc == -ETIMEDOUT)
699 i2c_recover_bus(&i2c->adap);
700
701 orig_jiffies = jiffies;
702 /* Wait until STOP is seen, allow up to 1 s */
703 while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
704 if (time_after(jiffies, orig_jiffies + HZ)) {
705 u8 status = readb(i2c->base + MPC_I2C_SR);
706
707 dev_dbg(i2c->dev, "timeout\n");
708 if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
709 writeb(status & ~CSR_MAL,
710 i2c->base + MPC_I2C_SR);
711 i2c_recover_bus(&i2c->adap);
712 }
713 return -EIO;
714 }
715 cond_resched();
716 }
717
718 return i2c->rc;
719 }
720
mpc_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)721 static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
722 {
723 int rc, ret = num;
724 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
725 int i;
726
727 dev_dbg(i2c->dev, "num = %d\n", num);
728 for (i = 0; i < num; i++)
729 dev_dbg(i2c->dev, " addr = %02x, flags = %02x, len = %d, %*ph\n",
730 msgs[i].addr, msgs[i].flags, msgs[i].len,
731 msgs[i].flags & I2C_M_RD ? 0 : msgs[i].len,
732 msgs[i].buf);
733
734 WARN_ON(i2c->msgs != NULL);
735 i2c->msgs = msgs;
736 i2c->num_msgs = num;
737
738 rc = mpc_i2c_execute_msg(i2c);
739 if (rc < 0)
740 ret = rc;
741
742 i2c->num_msgs = 0;
743 i2c->msgs = NULL;
744
745 return ret;
746 }
747
mpc_functionality(struct i2c_adapter * adap)748 static u32 mpc_functionality(struct i2c_adapter *adap)
749 {
750 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
751 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
752 }
753
fsl_i2c_bus_recovery(struct i2c_adapter * adap)754 static int fsl_i2c_bus_recovery(struct i2c_adapter *adap)
755 {
756 struct mpc_i2c *i2c = i2c_get_adapdata(adap);
757
758 if (i2c->has_errata_A004447)
759 mpc_i2c_fixup_A004447(i2c);
760 else
761 mpc_i2c_fixup(i2c);
762
763 return 0;
764 }
765
766 static const struct i2c_algorithm mpc_algo = {
767 .master_xfer = mpc_xfer,
768 .functionality = mpc_functionality,
769 };
770
771 static struct i2c_adapter mpc_ops = {
772 .owner = THIS_MODULE,
773 .algo = &mpc_algo,
774 };
775
776 static struct i2c_bus_recovery_info fsl_i2c_recovery_info = {
777 .recover_bus = fsl_i2c_bus_recovery,
778 };
779
fsl_i2c_probe(struct platform_device * op)780 static int fsl_i2c_probe(struct platform_device *op)
781 {
782 const struct mpc_i2c_data *data;
783 struct mpc_i2c *i2c;
784 struct clk *clk;
785 int result;
786 u32 clock;
787 int err;
788
789 i2c = devm_kzalloc(&op->dev, sizeof(*i2c), GFP_KERNEL);
790 if (!i2c)
791 return -ENOMEM;
792
793 i2c->dev = &op->dev; /* for debug and error output */
794
795 init_waitqueue_head(&i2c->waitq);
796 spin_lock_init(&i2c->lock);
797
798 i2c->base = devm_platform_ioremap_resource(op, 0);
799 if (IS_ERR(i2c->base))
800 return PTR_ERR(i2c->base);
801
802 i2c->irq = platform_get_irq(op, 0);
803 if (i2c->irq < 0)
804 return i2c->irq;
805
806 result = devm_request_irq(&op->dev, i2c->irq, mpc_i2c_isr,
807 IRQF_SHARED, "i2c-mpc", i2c);
808 if (result < 0) {
809 dev_err(i2c->dev, "failed to attach interrupt\n");
810 return result;
811 }
812
813 /*
814 * enable clock for the I2C peripheral (non fatal),
815 * keep a reference upon successful allocation
816 */
817 clk = devm_clk_get_optional(&op->dev, NULL);
818 if (IS_ERR(clk))
819 return PTR_ERR(clk);
820
821 err = clk_prepare_enable(clk);
822 if (err) {
823 dev_err(&op->dev, "failed to enable clock\n");
824 return err;
825 }
826
827 i2c->clk_per = clk;
828
829 if (of_property_read_bool(op->dev.of_node, "fsl,preserve-clocking")) {
830 clock = MPC_I2C_CLOCK_PRESERVE;
831 } else {
832 result = of_property_read_u32(op->dev.of_node,
833 "clock-frequency", &clock);
834 if (result)
835 clock = MPC_I2C_CLOCK_LEGACY;
836 }
837
838 data = device_get_match_data(&op->dev);
839 if (data) {
840 data->setup(op->dev.of_node, i2c, clock);
841 } else {
842 /* Backwards compatibility */
843 if (of_property_read_bool(op->dev.of_node, "dfsrr"))
844 mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock);
845 }
846
847 /*
848 * "fsl,timeout" has been marked as deprecated and, to maintain
849 * backward compatibility, we will only look for it if
850 * "i2c-scl-clk-low-timeout-us" is not present.
851 */
852 result = of_property_read_u32(op->dev.of_node,
853 "i2c-scl-clk-low-timeout-us",
854 &mpc_ops.timeout);
855 if (result == -EINVAL)
856 result = of_property_read_u32(op->dev.of_node,
857 "fsl,timeout", &mpc_ops.timeout);
858
859 if (!result) {
860 mpc_ops.timeout *= HZ / 1000000;
861 if (mpc_ops.timeout < 5)
862 mpc_ops.timeout = 5;
863 } else {
864 mpc_ops.timeout = HZ;
865 }
866
867 dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
868
869 if (of_property_read_bool(op->dev.of_node, "fsl,i2c-erratum-a004447"))
870 i2c->has_errata_A004447 = true;
871
872 i2c->adap = mpc_ops;
873 scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
874 "MPC adapter (%s)", of_node_full_name(op->dev.of_node));
875 i2c->adap.dev.parent = &op->dev;
876 i2c->adap.nr = op->id;
877 i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
878 i2c->adap.bus_recovery_info = &fsl_i2c_recovery_info;
879 platform_set_drvdata(op, i2c);
880 i2c_set_adapdata(&i2c->adap, i2c);
881
882 result = i2c_add_numbered_adapter(&i2c->adap);
883 if (result)
884 goto fail_add;
885
886 return 0;
887
888 fail_add:
889 clk_disable_unprepare(i2c->clk_per);
890
891 return result;
892 };
893
fsl_i2c_remove(struct platform_device * op)894 static void fsl_i2c_remove(struct platform_device *op)
895 {
896 struct mpc_i2c *i2c = platform_get_drvdata(op);
897
898 i2c_del_adapter(&i2c->adap);
899
900 clk_disable_unprepare(i2c->clk_per);
901 };
902
mpc_i2c_suspend(struct device * dev)903 static int __maybe_unused mpc_i2c_suspend(struct device *dev)
904 {
905 struct mpc_i2c *i2c = dev_get_drvdata(dev);
906
907 i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
908 i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
909
910 return 0;
911 }
912
mpc_i2c_resume(struct device * dev)913 static int __maybe_unused mpc_i2c_resume(struct device *dev)
914 {
915 struct mpc_i2c *i2c = dev_get_drvdata(dev);
916
917 writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
918 writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
919
920 return 0;
921 }
922 static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
923
924 static const struct mpc_i2c_data mpc_i2c_data_512x = {
925 .setup = mpc_i2c_setup_512x,
926 };
927
928 static const struct mpc_i2c_data mpc_i2c_data_52xx = {
929 .setup = mpc_i2c_setup_52xx,
930 };
931
932 static const struct mpc_i2c_data mpc_i2c_data_8313 = {
933 .setup = mpc_i2c_setup_8xxx,
934 };
935
936 static const struct mpc_i2c_data mpc_i2c_data_8543 = {
937 .setup = mpc_i2c_setup_8xxx,
938 };
939
940 static const struct mpc_i2c_data mpc_i2c_data_8544 = {
941 .setup = mpc_i2c_setup_8xxx,
942 };
943
944 static const struct of_device_id mpc_i2c_of_match[] = {
945 {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
946 {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
947 {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
948 {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
949 {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
950 {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
951 {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
952 /* Backward compatibility */
953 {.compatible = "fsl-i2c", },
954 {},
955 };
956 MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
957
958 /* Structure for a device driver */
959 static struct platform_driver mpc_i2c_driver = {
960 .probe = fsl_i2c_probe,
961 .remove_new = fsl_i2c_remove,
962 .driver = {
963 .name = DRV_NAME,
964 .of_match_table = mpc_i2c_of_match,
965 .pm = &mpc_i2c_pm_ops,
966 },
967 };
968
969 module_platform_driver(mpc_i2c_driver);
970
971 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
972 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
973 "MPC824x/83xx/85xx/86xx/512x/52xx processors");
974 MODULE_LICENSE("GPL");
975
