diff options
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/busses/Kconfig | 10 | ||||
-rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-octeon.c | 651 |
3 files changed, 662 insertions, 0 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 5f318ce29770..737f05200b1d 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig | |||
@@ -564,6 +564,16 @@ config I2C_VERSATILE | |||
564 | This driver can also be built as a module. If so, the module | 564 | This driver can also be built as a module. If so, the module |
565 | will be called i2c-versatile. | 565 | will be called i2c-versatile. |
566 | 566 | ||
567 | config I2C_OCTEON | ||
568 | tristate "Cavium OCTEON I2C bus support" | ||
569 | depends on CPU_CAVIUM_OCTEON | ||
570 | help | ||
571 | Say yes if you want to support the I2C serial bus on Cavium | ||
572 | OCTEON SOC. | ||
573 | |||
574 | This driver can also be built as a module. If so, the module | ||
575 | will be called i2c-octeon. | ||
576 | |||
567 | comment "External I2C/SMBus adapter drivers" | 577 | comment "External I2C/SMBus adapter drivers" |
568 | 578 | ||
569 | config I2C_PARPORT | 579 | config I2C_PARPORT |
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 302c551977bb..c2c4ea1908d8 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile | |||
@@ -54,6 +54,7 @@ obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o | |||
54 | obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o | 54 | obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o |
55 | obj-$(CONFIG_I2C_STU300) += i2c-stu300.o | 55 | obj-$(CONFIG_I2C_STU300) += i2c-stu300.o |
56 | obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o | 56 | obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o |
57 | obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o | ||
57 | 58 | ||
58 | # External I2C/SMBus adapter drivers | 59 | # External I2C/SMBus adapter drivers |
59 | obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o | 60 | obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o |
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c new file mode 100644 index 000000000000..60375504fa49 --- /dev/null +++ b/drivers/i2c/busses/i2c-octeon.c | |||
@@ -0,0 +1,651 @@ | |||
1 | /* | ||
2 | * (C) Copyright 2009-2010 | ||
3 | * Nokia Siemens Networks, michael.lawnick.ext@nsn.com | ||
4 | * | ||
5 | * Portions Copyright (C) 2010 Cavium Networks, Inc. | ||
6 | * | ||
7 | * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors. | ||
8 | * | ||
9 | * This file is licensed under the terms of the GNU General Public | ||
10 | * License version 2. This program is licensed "as is" without any | ||
11 | * warranty of any kind, whether express or implied. | ||
12 | */ | ||
13 | |||
14 | #include <linux/kernel.h> | ||
15 | #include <linux/module.h> | ||
16 | #include <linux/sched.h> | ||
17 | #include <linux/init.h> | ||
18 | |||
19 | #include <linux/io.h> | ||
20 | #include <linux/i2c.h> | ||
21 | #include <linux/interrupt.h> | ||
22 | #include <linux/delay.h> | ||
23 | #include <linux/platform_device.h> | ||
24 | |||
25 | #include <asm/octeon/octeon.h> | ||
26 | |||
27 | #define DRV_NAME "i2c-octeon" | ||
28 | |||
29 | /* The previous out-of-tree version was implicitly version 1.0. */ | ||
30 | #define DRV_VERSION "2.0" | ||
31 | |||
32 | /* register offsets */ | ||
33 | #define SW_TWSI 0x00 | ||
34 | #define TWSI_INT 0x10 | ||
35 | |||
36 | /* Controller command patterns */ | ||
37 | #define SW_TWSI_V 0x8000000000000000ull | ||
38 | #define SW_TWSI_EOP_TWSI_DATA 0x0C00000100000000ull | ||
39 | #define SW_TWSI_EOP_TWSI_CTL 0x0C00000200000000ull | ||
40 | #define SW_TWSI_EOP_TWSI_CLKCTL 0x0C00000300000000ull | ||
41 | #define SW_TWSI_EOP_TWSI_STAT 0x0C00000300000000ull | ||
42 | #define SW_TWSI_EOP_TWSI_RST 0x0C00000700000000ull | ||
43 | #define SW_TWSI_OP_TWSI_CLK 0x0800000000000000ull | ||
44 | #define SW_TWSI_R 0x0100000000000000ull | ||
45 | |||
46 | /* Controller command and status bits */ | ||
47 | #define TWSI_CTL_CE 0x80 | ||
48 | #define TWSI_CTL_ENAB 0x40 | ||
49 | #define TWSI_CTL_STA 0x20 | ||
50 | #define TWSI_CTL_STP 0x10 | ||
51 | #define TWSI_CTL_IFLG 0x08 | ||
52 | #define TWSI_CTL_AAK 0x04 | ||
53 | |||
54 | /* Some status values */ | ||
55 | #define STAT_START 0x08 | ||
56 | #define STAT_RSTART 0x10 | ||
57 | #define STAT_TXADDR_ACK 0x18 | ||
58 | #define STAT_TXDATA_ACK 0x28 | ||
59 | #define STAT_RXADDR_ACK 0x40 | ||
60 | #define STAT_RXDATA_ACK 0x50 | ||
61 | #define STAT_IDLE 0xF8 | ||
62 | |||
63 | struct octeon_i2c { | ||
64 | wait_queue_head_t queue; | ||
65 | struct i2c_adapter adap; | ||
66 | int irq; | ||
67 | int twsi_freq; | ||
68 | int sys_freq; | ||
69 | resource_size_t twsi_phys; | ||
70 | void __iomem *twsi_base; | ||
71 | resource_size_t regsize; | ||
72 | struct device *dev; | ||
73 | }; | ||
74 | |||
75 | /** | ||
76 | * octeon_i2c_write_sw - write an I2C core register. | ||
77 | * @i2c: The struct octeon_i2c. | ||
78 | * @eop_reg: Register selector. | ||
79 | * @data: Value to be written. | ||
80 | * | ||
81 | * The I2C core registers are accessed indirectly via the SW_TWSI CSR. | ||
82 | */ | ||
83 | static void octeon_i2c_write_sw(struct octeon_i2c *i2c, | ||
84 | u64 eop_reg, | ||
85 | u8 data) | ||
86 | { | ||
87 | u64 tmp; | ||
88 | |||
89 | __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI); | ||
90 | do { | ||
91 | tmp = __raw_readq(i2c->twsi_base + SW_TWSI); | ||
92 | } while ((tmp & SW_TWSI_V) != 0); | ||
93 | } | ||
94 | |||
95 | /** | ||
96 | * octeon_i2c_read_sw - write an I2C core register. | ||
97 | * @i2c: The struct octeon_i2c. | ||
98 | * @eop_reg: Register selector. | ||
99 | * | ||
100 | * Returns the data. | ||
101 | * | ||
102 | * The I2C core registers are accessed indirectly via the SW_TWSI CSR. | ||
103 | */ | ||
104 | static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg) | ||
105 | { | ||
106 | u64 tmp; | ||
107 | |||
108 | __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI); | ||
109 | do { | ||
110 | tmp = __raw_readq(i2c->twsi_base + SW_TWSI); | ||
111 | } while ((tmp & SW_TWSI_V) != 0); | ||
112 | |||
113 | return tmp & 0xFF; | ||
114 | } | ||
115 | |||
116 | /** | ||
117 | * octeon_i2c_write_int - write the TWSI_INT register | ||
118 | * @i2c: The struct octeon_i2c. | ||
119 | * @data: Value to be written. | ||
120 | */ | ||
121 | static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data) | ||
122 | { | ||
123 | u64 tmp; | ||
124 | |||
125 | __raw_writeq(data, i2c->twsi_base + TWSI_INT); | ||
126 | tmp = __raw_readq(i2c->twsi_base + TWSI_INT); | ||
127 | } | ||
128 | |||
129 | /** | ||
130 | * octeon_i2c_int_enable - enable the TS interrupt. | ||
131 | * @i2c: The struct octeon_i2c. | ||
132 | * | ||
133 | * The interrupt will be asserted when there is non-STAT_IDLE state in | ||
134 | * the SW_TWSI_EOP_TWSI_STAT register. | ||
135 | */ | ||
136 | static void octeon_i2c_int_enable(struct octeon_i2c *i2c) | ||
137 | { | ||
138 | octeon_i2c_write_int(i2c, 0x40); | ||
139 | } | ||
140 | |||
141 | /** | ||
142 | * octeon_i2c_int_disable - disable the TS interrupt. | ||
143 | * @i2c: The struct octeon_i2c. | ||
144 | */ | ||
145 | static void octeon_i2c_int_disable(struct octeon_i2c *i2c) | ||
146 | { | ||
147 | octeon_i2c_write_int(i2c, 0); | ||
148 | } | ||
149 | |||
150 | /** | ||
151 | * octeon_i2c_unblock - unblock the bus. | ||
152 | * @i2c: The struct octeon_i2c. | ||
153 | * | ||
154 | * If there was a reset while a device was driving 0 to bus, | ||
155 | * bus is blocked. We toggle it free manually by some clock | ||
156 | * cycles and send a stop. | ||
157 | */ | ||
158 | static void octeon_i2c_unblock(struct octeon_i2c *i2c) | ||
159 | { | ||
160 | int i; | ||
161 | |||
162 | dev_dbg(i2c->dev, "%s\n", __func__); | ||
163 | for (i = 0; i < 9; i++) { | ||
164 | octeon_i2c_write_int(i2c, 0x0); | ||
165 | udelay(5); | ||
166 | octeon_i2c_write_int(i2c, 0x200); | ||
167 | udelay(5); | ||
168 | } | ||
169 | octeon_i2c_write_int(i2c, 0x300); | ||
170 | udelay(5); | ||
171 | octeon_i2c_write_int(i2c, 0x100); | ||
172 | udelay(5); | ||
173 | octeon_i2c_write_int(i2c, 0x0); | ||
174 | } | ||
175 | |||
176 | /** | ||
177 | * octeon_i2c_isr - the interrupt service routine. | ||
178 | * @int: The irq, unused. | ||
179 | * @dev_id: Our struct octeon_i2c. | ||
180 | */ | ||
181 | static irqreturn_t octeon_i2c_isr(int irq, void *dev_id) | ||
182 | { | ||
183 | struct octeon_i2c *i2c = dev_id; | ||
184 | |||
185 | octeon_i2c_int_disable(i2c); | ||
186 | wake_up_interruptible(&i2c->queue); | ||
187 | |||
188 | return IRQ_HANDLED; | ||
189 | } | ||
190 | |||
191 | |||
192 | static int octeon_i2c_test_iflg(struct octeon_i2c *i2c) | ||
193 | { | ||
194 | return (octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_CTL) & TWSI_CTL_IFLG) != 0; | ||
195 | } | ||
196 | |||
197 | /** | ||
198 | * octeon_i2c_wait - wait for the IFLG to be set. | ||
199 | * @i2c: The struct octeon_i2c. | ||
200 | * | ||
201 | * Returns 0 on success, otherwise a negative errno. | ||
202 | */ | ||
203 | static int octeon_i2c_wait(struct octeon_i2c *i2c) | ||
204 | { | ||
205 | int result; | ||
206 | |||
207 | octeon_i2c_int_enable(i2c); | ||
208 | |||
209 | result = wait_event_interruptible_timeout(i2c->queue, | ||
210 | octeon_i2c_test_iflg(i2c), | ||
211 | i2c->adap.timeout); | ||
212 | |||
213 | octeon_i2c_int_disable(i2c); | ||
214 | |||
215 | if (result < 0) { | ||
216 | dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__); | ||
217 | return result; | ||
218 | } else if (result == 0) { | ||
219 | dev_dbg(i2c->dev, "%s: timeout\n", __func__); | ||
220 | result = -ETIMEDOUT; | ||
221 | } | ||
222 | |||
223 | return 0; | ||
224 | } | ||
225 | |||
226 | /** | ||
227 | * octeon_i2c_start - send START to the bus. | ||
228 | * @i2c: The struct octeon_i2c. | ||
229 | * | ||
230 | * Returns 0 on success, otherwise a negative errno. | ||
231 | */ | ||
232 | static int octeon_i2c_start(struct octeon_i2c *i2c) | ||
233 | { | ||
234 | u8 data; | ||
235 | int result; | ||
236 | |||
237 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, | ||
238 | TWSI_CTL_ENAB | TWSI_CTL_STA); | ||
239 | |||
240 | result = octeon_i2c_wait(i2c); | ||
241 | if (result) { | ||
242 | if (octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT) == STAT_IDLE) { | ||
243 | /* | ||
244 | * Controller refused to send start flag May | ||
245 | * be a client is holding SDA low - let's try | ||
246 | * to free it. | ||
247 | */ | ||
248 | octeon_i2c_unblock(i2c); | ||
249 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, | ||
250 | TWSI_CTL_ENAB | TWSI_CTL_STA); | ||
251 | |||
252 | result = octeon_i2c_wait(i2c); | ||
253 | } | ||
254 | if (result) | ||
255 | return result; | ||
256 | } | ||
257 | |||
258 | data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); | ||
259 | if ((data != STAT_START) && (data != STAT_RSTART)) { | ||
260 | dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data); | ||
261 | return -EIO; | ||
262 | } | ||
263 | |||
264 | return 0; | ||
265 | } | ||
266 | |||
267 | /** | ||
268 | * octeon_i2c_stop - send STOP to the bus. | ||
269 | * @i2c: The struct octeon_i2c. | ||
270 | * | ||
271 | * Returns 0 on success, otherwise a negative errno. | ||
272 | */ | ||
273 | static int octeon_i2c_stop(struct octeon_i2c *i2c) | ||
274 | { | ||
275 | u8 data; | ||
276 | |||
277 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, | ||
278 | TWSI_CTL_ENAB | TWSI_CTL_STP); | ||
279 | |||
280 | data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); | ||
281 | |||
282 | if (data != STAT_IDLE) { | ||
283 | dev_err(i2c->dev, "%s: bad status(0x%x)\n", __func__, data); | ||
284 | return -EIO; | ||
285 | } | ||
286 | return 0; | ||
287 | } | ||
288 | |||
289 | /** | ||
290 | * octeon_i2c_write - send data to the bus. | ||
291 | * @i2c: The struct octeon_i2c. | ||
292 | * @target: Target address. | ||
293 | * @data: Pointer to the data to be sent. | ||
294 | * @length: Length of the data. | ||
295 | * | ||
296 | * The address is sent over the bus, then the data. | ||
297 | * | ||
298 | * Returns 0 on success, otherwise a negative errno. | ||
299 | */ | ||
300 | static int octeon_i2c_write(struct octeon_i2c *i2c, int target, | ||
301 | const u8 *data, int length) | ||
302 | { | ||
303 | int i, result; | ||
304 | u8 tmp; | ||
305 | |||
306 | result = octeon_i2c_start(i2c); | ||
307 | if (result) | ||
308 | return result; | ||
309 | |||
310 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1); | ||
311 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); | ||
312 | |||
313 | result = octeon_i2c_wait(i2c); | ||
314 | if (result) | ||
315 | return result; | ||
316 | |||
317 | for (i = 0; i < length; i++) { | ||
318 | tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); | ||
319 | if ((tmp != STAT_TXADDR_ACK) && (tmp != STAT_TXDATA_ACK)) { | ||
320 | dev_err(i2c->dev, | ||
321 | "%s: bad status before write (0x%x)\n", | ||
322 | __func__, tmp); | ||
323 | return -EIO; | ||
324 | } | ||
325 | |||
326 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]); | ||
327 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); | ||
328 | |||
329 | result = octeon_i2c_wait(i2c); | ||
330 | if (result) | ||
331 | return result; | ||
332 | } | ||
333 | |||
334 | return 0; | ||
335 | } | ||
336 | |||
337 | /** | ||
338 | * octeon_i2c_read - receive data from the bus. | ||
339 | * @i2c: The struct octeon_i2c. | ||
340 | * @target: Target address. | ||
341 | * @data: Pointer to the location to store the datae . | ||
342 | * @length: Length of the data. | ||
343 | * | ||
344 | * The address is sent over the bus, then the data is read. | ||
345 | * | ||
346 | * Returns 0 on success, otherwise a negative errno. | ||
347 | */ | ||
348 | static int octeon_i2c_read(struct octeon_i2c *i2c, int target, | ||
349 | u8 *data, int length) | ||
350 | { | ||
351 | int i, result; | ||
352 | u8 tmp; | ||
353 | |||
354 | if (length < 1) | ||
355 | return -EINVAL; | ||
356 | |||
357 | result = octeon_i2c_start(i2c); | ||
358 | if (result) | ||
359 | return result; | ||
360 | |||
361 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target<<1) | 1); | ||
362 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); | ||
363 | |||
364 | result = octeon_i2c_wait(i2c); | ||
365 | if (result) | ||
366 | return result; | ||
367 | |||
368 | for (i = 0; i < length; i++) { | ||
369 | tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); | ||
370 | if ((tmp != STAT_RXDATA_ACK) && (tmp != STAT_RXADDR_ACK)) { | ||
371 | dev_err(i2c->dev, | ||
372 | "%s: bad status before read (0x%x)\n", | ||
373 | __func__, tmp); | ||
374 | return -EIO; | ||
375 | } | ||
376 | |||
377 | if (i+1 < length) | ||
378 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, | ||
379 | TWSI_CTL_ENAB | TWSI_CTL_AAK); | ||
380 | else | ||
381 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, | ||
382 | TWSI_CTL_ENAB); | ||
383 | |||
384 | result = octeon_i2c_wait(i2c); | ||
385 | if (result) | ||
386 | return result; | ||
387 | |||
388 | data[i] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA); | ||
389 | } | ||
390 | return 0; | ||
391 | } | ||
392 | |||
393 | /** | ||
394 | * octeon_i2c_xfer - The driver's master_xfer function. | ||
395 | * @adap: Pointer to the i2c_adapter structure. | ||
396 | * @msgs: Pointer to the messages to be processed. | ||
397 | * @num: Length of the MSGS array. | ||
398 | * | ||
399 | * Returns the number of messages processed, or a negative errno on | ||
400 | * failure. | ||
401 | */ | ||
402 | static int octeon_i2c_xfer(struct i2c_adapter *adap, | ||
403 | struct i2c_msg *msgs, | ||
404 | int num) | ||
405 | { | ||
406 | struct i2c_msg *pmsg; | ||
407 | int i; | ||
408 | int ret = 0; | ||
409 | struct octeon_i2c *i2c = i2c_get_adapdata(adap); | ||
410 | |||
411 | for (i = 0; ret == 0 && i < num; i++) { | ||
412 | pmsg = &msgs[i]; | ||
413 | dev_dbg(i2c->dev, | ||
414 | "Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n", | ||
415 | pmsg->flags & I2C_M_RD ? "read" : "write", | ||
416 | pmsg->len, pmsg->addr, i + 1, num); | ||
417 | if (pmsg->flags & I2C_M_RD) | ||
418 | ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf, | ||
419 | pmsg->len); | ||
420 | else | ||
421 | ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf, | ||
422 | pmsg->len); | ||
423 | } | ||
424 | octeon_i2c_stop(i2c); | ||
425 | |||
426 | return (ret != 0) ? ret : num; | ||
427 | } | ||
428 | |||
429 | static u32 octeon_i2c_functionality(struct i2c_adapter *adap) | ||
430 | { | ||
431 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; | ||
432 | } | ||
433 | |||
434 | static const struct i2c_algorithm octeon_i2c_algo = { | ||
435 | .master_xfer = octeon_i2c_xfer, | ||
436 | .functionality = octeon_i2c_functionality, | ||
437 | }; | ||
438 | |||
439 | static struct i2c_adapter octeon_i2c_ops = { | ||
440 | .owner = THIS_MODULE, | ||
441 | .name = "OCTEON adapter", | ||
442 | .algo = &octeon_i2c_algo, | ||
443 | .timeout = 2, | ||
444 | }; | ||
445 | |||
446 | /** | ||
447 | * octeon_i2c_setclock - Calculate and set clock divisors. | ||
448 | */ | ||
449 | static int __init octeon_i2c_setclock(struct octeon_i2c *i2c) | ||
450 | { | ||
451 | int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff; | ||
452 | int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000; | ||
453 | |||
454 | for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) { | ||
455 | /* | ||
456 | * An mdiv value of less than 2 seems to not work well | ||
457 | * with ds1337 RTCs, so we constrain it to larger | ||
458 | * values. | ||
459 | */ | ||
460 | for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) { | ||
461 | /* | ||
462 | * For given ndiv and mdiv values check the | ||
463 | * two closest thp values. | ||
464 | */ | ||
465 | tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10; | ||
466 | tclk *= (1 << ndiv_idx); | ||
467 | thp_base = (i2c->sys_freq / (tclk * 2)) - 1; | ||
468 | for (inc = 0; inc <= 1; inc++) { | ||
469 | thp_idx = thp_base + inc; | ||
470 | if (thp_idx < 5 || thp_idx > 0xff) | ||
471 | continue; | ||
472 | |||
473 | foscl = i2c->sys_freq / (2 * (thp_idx + 1)); | ||
474 | foscl = foscl / (1 << ndiv_idx); | ||
475 | foscl = foscl / (mdiv_idx + 1) / 10; | ||
476 | diff = abs(foscl - i2c->twsi_freq); | ||
477 | if (diff < delta_hz) { | ||
478 | delta_hz = diff; | ||
479 | thp = thp_idx; | ||
480 | mdiv = mdiv_idx; | ||
481 | ndiv = ndiv_idx; | ||
482 | } | ||
483 | } | ||
484 | } | ||
485 | } | ||
486 | octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp); | ||
487 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv); | ||
488 | |||
489 | return 0; | ||
490 | } | ||
491 | |||
492 | static int __init octeon_i2c_initlowlevel(struct octeon_i2c *i2c) | ||
493 | { | ||
494 | u8 status; | ||
495 | int tries; | ||
496 | |||
497 | /* disable high level controller, enable bus access */ | ||
498 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); | ||
499 | |||
500 | /* reset controller */ | ||
501 | octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0); | ||
502 | |||
503 | for (tries = 10; tries; tries--) { | ||
504 | udelay(1); | ||
505 | status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); | ||
506 | if (status == STAT_IDLE) | ||
507 | return 0; | ||
508 | } | ||
509 | dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status); | ||
510 | return -EIO; | ||
511 | } | ||
512 | |||
513 | static int __devinit octeon_i2c_probe(struct platform_device *pdev) | ||
514 | { | ||
515 | int irq, result = 0; | ||
516 | struct octeon_i2c *i2c; | ||
517 | struct octeon_i2c_data *i2c_data; | ||
518 | struct resource *res_mem; | ||
519 | |||
520 | /* All adaptors have an irq. */ | ||
521 | irq = platform_get_irq(pdev, 0); | ||
522 | if (irq < 0) | ||
523 | return irq; | ||
524 | |||
525 | i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); | ||
526 | if (!i2c) { | ||
527 | dev_err(&pdev->dev, "kzalloc failed\n"); | ||
528 | result = -ENOMEM; | ||
529 | goto out; | ||
530 | } | ||
531 | i2c->dev = &pdev->dev; | ||
532 | i2c_data = pdev->dev.platform_data; | ||
533 | |||
534 | res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
535 | |||
536 | if (res_mem == NULL) { | ||
537 | dev_err(i2c->dev, "found no memory resource\n"); | ||
538 | result = -ENXIO; | ||
539 | goto fail_region; | ||
540 | } | ||
541 | |||
542 | if (i2c_data == NULL) { | ||
543 | dev_err(i2c->dev, "no I2C frequency data\n"); | ||
544 | result = -ENXIO; | ||
545 | goto fail_region; | ||
546 | } | ||
547 | |||
548 | i2c->twsi_phys = res_mem->start; | ||
549 | i2c->regsize = resource_size(res_mem); | ||
550 | i2c->twsi_freq = i2c_data->i2c_freq; | ||
551 | i2c->sys_freq = i2c_data->sys_freq; | ||
552 | |||
553 | if (!request_mem_region(i2c->twsi_phys, i2c->regsize, res_mem->name)) { | ||
554 | dev_err(i2c->dev, "request_mem_region failed\n"); | ||
555 | goto fail_region; | ||
556 | } | ||
557 | i2c->twsi_base = ioremap(i2c->twsi_phys, i2c->regsize); | ||
558 | |||
559 | init_waitqueue_head(&i2c->queue); | ||
560 | |||
561 | i2c->irq = irq; | ||
562 | |||
563 | result = request_irq(i2c->irq, octeon_i2c_isr, 0, DRV_NAME, i2c); | ||
564 | if (result < 0) { | ||
565 | dev_err(i2c->dev, "failed to attach interrupt\n"); | ||
566 | goto fail_irq; | ||
567 | } | ||
568 | |||
569 | result = octeon_i2c_initlowlevel(i2c); | ||
570 | if (result) { | ||
571 | dev_err(i2c->dev, "init low level failed\n"); | ||
572 | goto fail_add; | ||
573 | } | ||
574 | |||
575 | result = octeon_i2c_setclock(i2c); | ||
576 | if (result) { | ||
577 | dev_err(i2c->dev, "clock init failed\n"); | ||
578 | goto fail_add; | ||
579 | } | ||
580 | |||
581 | i2c->adap = octeon_i2c_ops; | ||
582 | i2c->adap.dev.parent = &pdev->dev; | ||
583 | i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0; | ||
584 | i2c_set_adapdata(&i2c->adap, i2c); | ||
585 | platform_set_drvdata(pdev, i2c); | ||
586 | |||
587 | result = i2c_add_numbered_adapter(&i2c->adap); | ||
588 | if (result < 0) { | ||
589 | dev_err(i2c->dev, "failed to add adapter\n"); | ||
590 | goto fail_add; | ||
591 | } | ||
592 | |||
593 | dev_info(i2c->dev, "version %s\n", DRV_VERSION); | ||
594 | |||
595 | return result; | ||
596 | |||
597 | fail_add: | ||
598 | platform_set_drvdata(pdev, NULL); | ||
599 | free_irq(i2c->irq, i2c); | ||
600 | fail_irq: | ||
601 | iounmap(i2c->twsi_base); | ||
602 | release_mem_region(i2c->twsi_phys, i2c->regsize); | ||
603 | fail_region: | ||
604 | kfree(i2c); | ||
605 | out: | ||
606 | return result; | ||
607 | }; | ||
608 | |||
609 | static int __devexit octeon_i2c_remove(struct platform_device *pdev) | ||
610 | { | ||
611 | struct octeon_i2c *i2c = platform_get_drvdata(pdev); | ||
612 | |||
613 | i2c_del_adapter(&i2c->adap); | ||
614 | platform_set_drvdata(pdev, NULL); | ||
615 | free_irq(i2c->irq, i2c); | ||
616 | iounmap(i2c->twsi_base); | ||
617 | release_mem_region(i2c->twsi_phys, i2c->regsize); | ||
618 | kfree(i2c); | ||
619 | return 0; | ||
620 | }; | ||
621 | |||
622 | static struct platform_driver octeon_i2c_driver = { | ||
623 | .probe = octeon_i2c_probe, | ||
624 | .remove = __devexit_p(octeon_i2c_remove), | ||
625 | .driver = { | ||
626 | .owner = THIS_MODULE, | ||
627 | .name = DRV_NAME, | ||
628 | }, | ||
629 | }; | ||
630 | |||
631 | static int __init octeon_i2c_init(void) | ||
632 | { | ||
633 | int rv; | ||
634 | |||
635 | rv = platform_driver_register(&octeon_i2c_driver); | ||
636 | return rv; | ||
637 | } | ||
638 | |||
639 | static void __exit octeon_i2c_exit(void) | ||
640 | { | ||
641 | platform_driver_unregister(&octeon_i2c_driver); | ||
642 | } | ||
643 | |||
644 | MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>"); | ||
645 | MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors"); | ||
646 | MODULE_LICENSE("GPL"); | ||
647 | MODULE_VERSION(DRV_VERSION); | ||
648 | MODULE_ALIAS("platform:" DRV_NAME); | ||
649 | |||
650 | module_init(octeon_i2c_init); | ||
651 | module_exit(octeon_i2c_exit); | ||