Commit | Line | Data |
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e1d5b659 RR |
1 | /* |
2 | * i2c-xiic.c | |
3 | * Copyright (c) 2002-2007 Xilinx Inc. | |
4 | * Copyright (c) 2009-2010 Intel Corporation | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
e1d5b659 RR |
15 | * |
16 | * This code was implemented by Mocean Laboratories AB when porting linux | |
17 | * to the automotive development board Russellville. The copyright holder | |
18 | * as seen in the header is Intel corporation. | |
19 | * Mocean Laboratories forked off the GNU/Linux platform work into a | |
25985edc | 20 | * separate company called Pelagicore AB, which committed the code to the |
e1d5b659 RR |
21 | * kernel. |
22 | */ | |
23 | ||
24 | /* Supports: | |
25 | * Xilinx IIC | |
26 | */ | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/module.h> | |
e1d5b659 | 29 | #include <linux/errno.h> |
168e722d | 30 | #include <linux/err.h> |
02ca6c40 | 31 | #include <linux/delay.h> |
e1d5b659 RR |
32 | #include <linux/platform_device.h> |
33 | #include <linux/i2c.h> | |
34 | #include <linux/interrupt.h> | |
35 | #include <linux/wait.h> | |
36 | #include <linux/i2c-xiic.h> | |
37 | #include <linux/io.h> | |
5a0e3ad6 | 38 | #include <linux/slab.h> |
4edd65e6 | 39 | #include <linux/of.h> |
e1d5b659 RR |
40 | |
41 | #define DRIVER_NAME "xiic-i2c" | |
42 | ||
43 | enum xilinx_i2c_state { | |
44 | STATE_DONE, | |
45 | STATE_ERROR, | |
46 | STATE_START | |
47 | }; | |
48 | ||
48ef3ca9 TG |
49 | enum xiic_endian { |
50 | LITTLE, | |
51 | BIG | |
52 | }; | |
53 | ||
e1d5b659 RR |
54 | /** |
55 | * struct xiic_i2c - Internal representation of the XIIC I2C bus | |
56 | * @base: Memory base of the HW registers | |
57 | * @wait: Wait queue for callers | |
58 | * @adap: Kernel adapter representation | |
59 | * @tx_msg: Messages from above to be sent | |
60 | * @lock: Mutual exclusion | |
61 | * @tx_pos: Current pos in TX message | |
62 | * @nmsgs: Number of messages in tx_msg | |
63 | * @state: See STATE_ | |
64 | * @rx_msg: Current RX message | |
65 | * @rx_pos: Position within current RX message | |
bea6ff02 | 66 | * @endianness: big/little-endian byte order |
e1d5b659 RR |
67 | */ |
68 | struct xiic_i2c { | |
69 | void __iomem *base; | |
70 | wait_queue_head_t wait; | |
71 | struct i2c_adapter adap; | |
72 | struct i2c_msg *tx_msg; | |
73 | spinlock_t lock; | |
f1e9f89a | 74 | unsigned int tx_pos; |
e1d5b659 RR |
75 | unsigned int nmsgs; |
76 | enum xilinx_i2c_state state; | |
77 | struct i2c_msg *rx_msg; | |
78 | int rx_pos; | |
48ef3ca9 | 79 | enum xiic_endian endianness; |
e1d5b659 RR |
80 | }; |
81 | ||
82 | ||
83 | #define XIIC_MSB_OFFSET 0 | |
84 | #define XIIC_REG_OFFSET (0x100+XIIC_MSB_OFFSET) | |
85 | ||
86 | /* | |
87 | * Register offsets in bytes from RegisterBase. Three is added to the | |
88 | * base offset to access LSB (IBM style) of the word | |
89 | */ | |
90 | #define XIIC_CR_REG_OFFSET (0x00+XIIC_REG_OFFSET) /* Control Register */ | |
91 | #define XIIC_SR_REG_OFFSET (0x04+XIIC_REG_OFFSET) /* Status Register */ | |
92 | #define XIIC_DTR_REG_OFFSET (0x08+XIIC_REG_OFFSET) /* Data Tx Register */ | |
93 | #define XIIC_DRR_REG_OFFSET (0x0C+XIIC_REG_OFFSET) /* Data Rx Register */ | |
94 | #define XIIC_ADR_REG_OFFSET (0x10+XIIC_REG_OFFSET) /* Address Register */ | |
95 | #define XIIC_TFO_REG_OFFSET (0x14+XIIC_REG_OFFSET) /* Tx FIFO Occupancy */ | |
96 | #define XIIC_RFO_REG_OFFSET (0x18+XIIC_REG_OFFSET) /* Rx FIFO Occupancy */ | |
97 | #define XIIC_TBA_REG_OFFSET (0x1C+XIIC_REG_OFFSET) /* 10 Bit Address reg */ | |
98 | #define XIIC_RFD_REG_OFFSET (0x20+XIIC_REG_OFFSET) /* Rx FIFO Depth reg */ | |
99 | #define XIIC_GPO_REG_OFFSET (0x24+XIIC_REG_OFFSET) /* Output Register */ | |
100 | ||
101 | /* Control Register masks */ | |
102 | #define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */ | |
103 | #define XIIC_CR_TX_FIFO_RESET_MASK 0x02 /* Transmit FIFO reset=1 */ | |
104 | #define XIIC_CR_MSMS_MASK 0x04 /* Master starts Txing=1 */ | |
105 | #define XIIC_CR_DIR_IS_TX_MASK 0x08 /* Dir of tx. Txing=1 */ | |
106 | #define XIIC_CR_NO_ACK_MASK 0x10 /* Tx Ack. NO ack = 1 */ | |
107 | #define XIIC_CR_REPEATED_START_MASK 0x20 /* Repeated start = 1 */ | |
108 | #define XIIC_CR_GENERAL_CALL_MASK 0x40 /* Gen Call enabled = 1 */ | |
109 | ||
110 | /* Status Register masks */ | |
111 | #define XIIC_SR_GEN_CALL_MASK 0x01 /* 1=a mstr issued a GC */ | |
112 | #define XIIC_SR_ADDR_AS_SLAVE_MASK 0x02 /* 1=when addr as slave */ | |
113 | #define XIIC_SR_BUS_BUSY_MASK 0x04 /* 1 = bus is busy */ | |
114 | #define XIIC_SR_MSTR_RDING_SLAVE_MASK 0x08 /* 1=Dir: mstr <-- slave */ | |
115 | #define XIIC_SR_TX_FIFO_FULL_MASK 0x10 /* 1 = Tx FIFO full */ | |
116 | #define XIIC_SR_RX_FIFO_FULL_MASK 0x20 /* 1 = Rx FIFO full */ | |
117 | #define XIIC_SR_RX_FIFO_EMPTY_MASK 0x40 /* 1 = Rx FIFO empty */ | |
118 | #define XIIC_SR_TX_FIFO_EMPTY_MASK 0x80 /* 1 = Tx FIFO empty */ | |
119 | ||
120 | /* Interrupt Status Register masks Interrupt occurs when... */ | |
121 | #define XIIC_INTR_ARB_LOST_MASK 0x01 /* 1 = arbitration lost */ | |
122 | #define XIIC_INTR_TX_ERROR_MASK 0x02 /* 1=Tx error/msg complete */ | |
123 | #define XIIC_INTR_TX_EMPTY_MASK 0x04 /* 1 = Tx FIFO/reg empty */ | |
124 | #define XIIC_INTR_RX_FULL_MASK 0x08 /* 1=Rx FIFO/reg=OCY level */ | |
125 | #define XIIC_INTR_BNB_MASK 0x10 /* 1 = Bus not busy */ | |
126 | #define XIIC_INTR_AAS_MASK 0x20 /* 1 = when addr as slave */ | |
127 | #define XIIC_INTR_NAAS_MASK 0x40 /* 1 = not addr as slave */ | |
128 | #define XIIC_INTR_TX_HALF_MASK 0x80 /* 1 = TX FIFO half empty */ | |
129 | ||
130 | /* The following constants specify the depth of the FIFOs */ | |
131 | #define IIC_RX_FIFO_DEPTH 16 /* Rx fifo capacity */ | |
132 | #define IIC_TX_FIFO_DEPTH 16 /* Tx fifo capacity */ | |
133 | ||
134 | /* The following constants specify groups of interrupts that are typically | |
135 | * enabled or disables at the same time | |
136 | */ | |
137 | #define XIIC_TX_INTERRUPTS \ | |
138 | (XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK) | |
139 | ||
140 | #define XIIC_TX_RX_INTERRUPTS (XIIC_INTR_RX_FULL_MASK | XIIC_TX_INTERRUPTS) | |
141 | ||
142 | /* The following constants are used with the following macros to specify the | |
143 | * operation, a read or write operation. | |
144 | */ | |
145 | #define XIIC_READ_OPERATION 1 | |
146 | #define XIIC_WRITE_OPERATION 0 | |
147 | ||
148 | /* | |
149 | * Tx Fifo upper bit masks. | |
150 | */ | |
151 | #define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */ | |
152 | #define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */ | |
153 | ||
154 | /* | |
155 | * The following constants define the register offsets for the Interrupt | |
156 | * registers. There are some holes in the memory map for reserved addresses | |
157 | * to allow other registers to be added and still match the memory map of the | |
158 | * interrupt controller registers | |
159 | */ | |
160 | #define XIIC_DGIER_OFFSET 0x1C /* Device Global Interrupt Enable Register */ | |
161 | #define XIIC_IISR_OFFSET 0x20 /* Interrupt Status Register */ | |
162 | #define XIIC_IIER_OFFSET 0x28 /* Interrupt Enable Register */ | |
163 | #define XIIC_RESETR_OFFSET 0x40 /* Reset Register */ | |
164 | ||
165 | #define XIIC_RESET_MASK 0xAUL | |
166 | ||
167 | /* | |
168 | * The following constant is used for the device global interrupt enable | |
169 | * register, to enable all interrupts for the device, this is the only bit | |
170 | * in the register | |
171 | */ | |
172 | #define XIIC_GINTR_ENABLE_MASK 0x80000000UL | |
173 | ||
174 | #define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos) | |
175 | #define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos) | |
176 | ||
177 | static void xiic_start_xfer(struct xiic_i2c *i2c); | |
178 | static void __xiic_start_xfer(struct xiic_i2c *i2c); | |
179 | ||
48ef3ca9 TG |
180 | /* |
181 | * For the register read and write functions, a little-endian and big-endian | |
182 | * version are necessary. Endianness is detected during the probe function. | |
183 | * Only the least significant byte [doublet] of the register are ever | |
184 | * accessed. This requires an offset of 3 [2] from the base address for | |
185 | * big-endian systems. | |
186 | */ | |
187 | ||
e1d5b659 RR |
188 | static inline void xiic_setreg8(struct xiic_i2c *i2c, int reg, u8 value) |
189 | { | |
48ef3ca9 TG |
190 | if (i2c->endianness == LITTLE) |
191 | iowrite8(value, i2c->base + reg); | |
192 | else | |
193 | iowrite8(value, i2c->base + reg + 3); | |
e1d5b659 RR |
194 | } |
195 | ||
196 | static inline u8 xiic_getreg8(struct xiic_i2c *i2c, int reg) | |
197 | { | |
48ef3ca9 TG |
198 | u8 ret; |
199 | ||
200 | if (i2c->endianness == LITTLE) | |
201 | ret = ioread8(i2c->base + reg); | |
202 | else | |
203 | ret = ioread8(i2c->base + reg + 3); | |
204 | return ret; | |
e1d5b659 RR |
205 | } |
206 | ||
207 | static inline void xiic_setreg16(struct xiic_i2c *i2c, int reg, u16 value) | |
208 | { | |
48ef3ca9 TG |
209 | if (i2c->endianness == LITTLE) |
210 | iowrite16(value, i2c->base + reg); | |
211 | else | |
212 | iowrite16be(value, i2c->base + reg + 2); | |
e1d5b659 RR |
213 | } |
214 | ||
215 | static inline void xiic_setreg32(struct xiic_i2c *i2c, int reg, int value) | |
216 | { | |
48ef3ca9 TG |
217 | if (i2c->endianness == LITTLE) |
218 | iowrite32(value, i2c->base + reg); | |
219 | else | |
220 | iowrite32be(value, i2c->base + reg); | |
e1d5b659 RR |
221 | } |
222 | ||
223 | static inline int xiic_getreg32(struct xiic_i2c *i2c, int reg) | |
224 | { | |
48ef3ca9 TG |
225 | u32 ret; |
226 | ||
227 | if (i2c->endianness == LITTLE) | |
228 | ret = ioread32(i2c->base + reg); | |
229 | else | |
230 | ret = ioread32be(i2c->base + reg); | |
231 | return ret; | |
e1d5b659 RR |
232 | } |
233 | ||
234 | static inline void xiic_irq_dis(struct xiic_i2c *i2c, u32 mask) | |
235 | { | |
236 | u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
237 | xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier & ~mask); | |
238 | } | |
239 | ||
240 | static inline void xiic_irq_en(struct xiic_i2c *i2c, u32 mask) | |
241 | { | |
242 | u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
243 | xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier | mask); | |
244 | } | |
245 | ||
246 | static inline void xiic_irq_clr(struct xiic_i2c *i2c, u32 mask) | |
247 | { | |
248 | u32 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); | |
249 | xiic_setreg32(i2c, XIIC_IISR_OFFSET, isr & mask); | |
250 | } | |
251 | ||
252 | static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask) | |
253 | { | |
254 | xiic_irq_clr(i2c, mask); | |
255 | xiic_irq_en(i2c, mask); | |
256 | } | |
257 | ||
258 | static void xiic_clear_rx_fifo(struct xiic_i2c *i2c) | |
259 | { | |
260 | u8 sr; | |
261 | for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET); | |
262 | !(sr & XIIC_SR_RX_FIFO_EMPTY_MASK); | |
263 | sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)) | |
264 | xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); | |
265 | } | |
266 | ||
267 | static void xiic_reinit(struct xiic_i2c *i2c) | |
268 | { | |
269 | xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK); | |
270 | ||
271 | /* Set receive Fifo depth to maximum (zero based). */ | |
272 | xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1); | |
273 | ||
274 | /* Reset Tx Fifo. */ | |
275 | xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK); | |
276 | ||
277 | /* Enable IIC Device, remove Tx Fifo reset & disable general call. */ | |
278 | xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK); | |
279 | ||
280 | /* make sure RX fifo is empty */ | |
281 | xiic_clear_rx_fifo(i2c); | |
282 | ||
283 | /* Enable interrupts */ | |
284 | xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); | |
285 | ||
542e2a9b | 286 | xiic_irq_clr_en(i2c, XIIC_INTR_ARB_LOST_MASK); |
e1d5b659 RR |
287 | } |
288 | ||
289 | static void xiic_deinit(struct xiic_i2c *i2c) | |
290 | { | |
291 | u8 cr; | |
292 | ||
293 | xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK); | |
294 | ||
295 | /* Disable IIC Device. */ | |
296 | cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); | |
297 | xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK); | |
298 | } | |
299 | ||
300 | static void xiic_read_rx(struct xiic_i2c *i2c) | |
301 | { | |
302 | u8 bytes_in_fifo; | |
303 | int i; | |
304 | ||
305 | bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1; | |
306 | ||
f1e9f89a KA |
307 | dev_dbg(i2c->adap.dev.parent, |
308 | "%s entry, bytes in fifo: %d, msg: %d, SR: 0x%x, CR: 0x%x\n", | |
e1d5b659 RR |
309 | __func__, bytes_in_fifo, xiic_rx_space(i2c), |
310 | xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), | |
311 | xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); | |
312 | ||
313 | if (bytes_in_fifo > xiic_rx_space(i2c)) | |
314 | bytes_in_fifo = xiic_rx_space(i2c); | |
315 | ||
316 | for (i = 0; i < bytes_in_fifo; i++) | |
317 | i2c->rx_msg->buf[i2c->rx_pos++] = | |
318 | xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); | |
319 | ||
320 | xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, | |
321 | (xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ? | |
322 | IIC_RX_FIFO_DEPTH - 1 : xiic_rx_space(i2c) - 1); | |
323 | } | |
324 | ||
325 | static int xiic_tx_fifo_space(struct xiic_i2c *i2c) | |
326 | { | |
327 | /* return the actual space left in the FIFO */ | |
328 | return IIC_TX_FIFO_DEPTH - xiic_getreg8(i2c, XIIC_TFO_REG_OFFSET) - 1; | |
329 | } | |
330 | ||
331 | static void xiic_fill_tx_fifo(struct xiic_i2c *i2c) | |
332 | { | |
333 | u8 fifo_space = xiic_tx_fifo_space(i2c); | |
334 | int len = xiic_tx_space(i2c); | |
335 | ||
336 | len = (len > fifo_space) ? fifo_space : len; | |
337 | ||
338 | dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n", | |
339 | __func__, len, fifo_space); | |
340 | ||
341 | while (len--) { | |
342 | u16 data = i2c->tx_msg->buf[i2c->tx_pos++]; | |
343 | if ((xiic_tx_space(i2c) == 0) && (i2c->nmsgs == 1)) { | |
344 | /* last message in transfer -> STOP */ | |
345 | data |= XIIC_TX_DYN_STOP_MASK; | |
346 | dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__); | |
c39e8e43 SF |
347 | } |
348 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); | |
e1d5b659 RR |
349 | } |
350 | } | |
351 | ||
352 | static void xiic_wakeup(struct xiic_i2c *i2c, int code) | |
353 | { | |
354 | i2c->tx_msg = NULL; | |
355 | i2c->rx_msg = NULL; | |
356 | i2c->nmsgs = 0; | |
357 | i2c->state = code; | |
358 | wake_up(&i2c->wait); | |
359 | } | |
360 | ||
fcc2fac6 | 361 | static irqreturn_t xiic_process(int irq, void *dev_id) |
e1d5b659 | 362 | { |
fcc2fac6 | 363 | struct xiic_i2c *i2c = dev_id; |
e1d5b659 RR |
364 | u32 pend, isr, ier; |
365 | u32 clr = 0; | |
366 | ||
367 | /* Get the interrupt Status from the IPIF. There is no clearing of | |
368 | * interrupts in the IPIF. Interrupts must be cleared at the source. | |
369 | * To find which interrupts are pending; AND interrupts pending with | |
370 | * interrupts masked. | |
371 | */ | |
fcc2fac6 | 372 | spin_lock(&i2c->lock); |
e1d5b659 RR |
373 | isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); |
374 | ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
375 | pend = isr & ier; | |
376 | ||
f1e9f89a KA |
377 | dev_dbg(i2c->adap.dev.parent, "%s: IER: 0x%x, ISR: 0x%x, pend: 0x%x\n", |
378 | __func__, ier, isr, pend); | |
379 | dev_dbg(i2c->adap.dev.parent, "%s: SR: 0x%x, msg: %p, nmsgs: %d\n", | |
380 | __func__, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), | |
e1d5b659 RR |
381 | i2c->tx_msg, i2c->nmsgs); |
382 | ||
e1d5b659 RR |
383 | |
384 | /* Service requesting interrupt */ | |
385 | if ((pend & XIIC_INTR_ARB_LOST_MASK) || | |
386 | ((pend & XIIC_INTR_TX_ERROR_MASK) && | |
387 | !(pend & XIIC_INTR_RX_FULL_MASK))) { | |
388 | /* bus arbritration lost, or... | |
389 | * Transmit error _OR_ RX completed | |
390 | * if this happens when RX_FULL is not set | |
391 | * this is probably a TX error | |
392 | */ | |
393 | ||
394 | dev_dbg(i2c->adap.dev.parent, "%s error\n", __func__); | |
395 | ||
396 | /* dynamic mode seem to suffer from problems if we just flushes | |
397 | * fifos and the next message is a TX with len 0 (only addr) | |
398 | * reset the IP instead of just flush fifos | |
399 | */ | |
400 | xiic_reinit(i2c); | |
401 | ||
6b0c8dc3 SD |
402 | if (i2c->rx_msg) |
403 | xiic_wakeup(i2c, STATE_ERROR); | |
e1d5b659 RR |
404 | if (i2c->tx_msg) |
405 | xiic_wakeup(i2c, STATE_ERROR); | |
7f9906bd SD |
406 | } |
407 | if (pend & XIIC_INTR_RX_FULL_MASK) { | |
e1d5b659 RR |
408 | /* Receive register/FIFO is full */ |
409 | ||
7f9906bd | 410 | clr |= XIIC_INTR_RX_FULL_MASK; |
e1d5b659 RR |
411 | if (!i2c->rx_msg) { |
412 | dev_dbg(i2c->adap.dev.parent, | |
413 | "%s unexpexted RX IRQ\n", __func__); | |
414 | xiic_clear_rx_fifo(i2c); | |
415 | goto out; | |
416 | } | |
417 | ||
418 | xiic_read_rx(i2c); | |
419 | if (xiic_rx_space(i2c) == 0) { | |
420 | /* this is the last part of the message */ | |
421 | i2c->rx_msg = NULL; | |
422 | ||
423 | /* also clear TX error if there (RX complete) */ | |
424 | clr |= (isr & XIIC_INTR_TX_ERROR_MASK); | |
425 | ||
426 | dev_dbg(i2c->adap.dev.parent, | |
427 | "%s end of message, nmsgs: %d\n", | |
428 | __func__, i2c->nmsgs); | |
429 | ||
430 | /* send next message if this wasn't the last, | |
431 | * otherwise the transfer will be finialise when | |
432 | * receiving the bus not busy interrupt | |
433 | */ | |
434 | if (i2c->nmsgs > 1) { | |
435 | i2c->nmsgs--; | |
436 | i2c->tx_msg++; | |
437 | dev_dbg(i2c->adap.dev.parent, | |
438 | "%s will start next...\n", __func__); | |
439 | ||
440 | __xiic_start_xfer(i2c); | |
441 | } | |
442 | } | |
7f9906bd SD |
443 | } |
444 | if (pend & XIIC_INTR_BNB_MASK) { | |
e1d5b659 | 445 | /* IIC bus has transitioned to not busy */ |
7f9906bd | 446 | clr |= XIIC_INTR_BNB_MASK; |
e1d5b659 RR |
447 | |
448 | /* The bus is not busy, disable BusNotBusy interrupt */ | |
449 | xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK); | |
450 | ||
451 | if (!i2c->tx_msg) | |
452 | goto out; | |
453 | ||
454 | if ((i2c->nmsgs == 1) && !i2c->rx_msg && | |
455 | xiic_tx_space(i2c) == 0) | |
456 | xiic_wakeup(i2c, STATE_DONE); | |
457 | else | |
458 | xiic_wakeup(i2c, STATE_ERROR); | |
7f9906bd SD |
459 | } |
460 | if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) { | |
d36b6910 | 461 | /* Transmit register/FIFO is empty or ½ empty */ |
e1d5b659 | 462 | |
7f9906bd SD |
463 | clr |= (pend & |
464 | (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)); | |
e1d5b659 RR |
465 | |
466 | if (!i2c->tx_msg) { | |
467 | dev_dbg(i2c->adap.dev.parent, | |
468 | "%s unexpexted TX IRQ\n", __func__); | |
469 | goto out; | |
470 | } | |
471 | ||
472 | xiic_fill_tx_fifo(i2c); | |
473 | ||
474 | /* current message sent and there is space in the fifo */ | |
475 | if (!xiic_tx_space(i2c) && xiic_tx_fifo_space(i2c) >= 2) { | |
476 | dev_dbg(i2c->adap.dev.parent, | |
477 | "%s end of message sent, nmsgs: %d\n", | |
478 | __func__, i2c->nmsgs); | |
479 | if (i2c->nmsgs > 1) { | |
480 | i2c->nmsgs--; | |
481 | i2c->tx_msg++; | |
482 | __xiic_start_xfer(i2c); | |
483 | } else { | |
484 | xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK); | |
485 | ||
486 | dev_dbg(i2c->adap.dev.parent, | |
487 | "%s Got TX IRQ but no more to do...\n", | |
488 | __func__); | |
489 | } | |
490 | } else if (!xiic_tx_space(i2c) && (i2c->nmsgs == 1)) | |
491 | /* current frame is sent and is last, | |
492 | * make sure to disable tx half | |
493 | */ | |
494 | xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK); | |
e1d5b659 RR |
495 | } |
496 | out: | |
497 | dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr); | |
498 | ||
499 | xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr); | |
fcc2fac6 SD |
500 | spin_unlock(&i2c->lock); |
501 | return IRQ_HANDLED; | |
e1d5b659 RR |
502 | } |
503 | ||
504 | static int xiic_bus_busy(struct xiic_i2c *i2c) | |
505 | { | |
506 | u8 sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET); | |
507 | ||
508 | return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0; | |
509 | } | |
510 | ||
511 | static int xiic_busy(struct xiic_i2c *i2c) | |
512 | { | |
513 | int tries = 3; | |
514 | int err; | |
515 | ||
516 | if (i2c->tx_msg) | |
517 | return -EBUSY; | |
518 | ||
519 | /* for instance if previous transfer was terminated due to TX error | |
520 | * it might be that the bus is on it's way to become available | |
521 | * give it at most 3 ms to wake | |
522 | */ | |
523 | err = xiic_bus_busy(i2c); | |
524 | while (err && tries--) { | |
b33aa252 | 525 | msleep(1); |
e1d5b659 RR |
526 | err = xiic_bus_busy(i2c); |
527 | } | |
528 | ||
529 | return err; | |
530 | } | |
531 | ||
532 | static void xiic_start_recv(struct xiic_i2c *i2c) | |
533 | { | |
534 | u8 rx_watermark; | |
535 | struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg; | |
536 | ||
537 | /* Clear and enable Rx full interrupt. */ | |
538 | xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK); | |
539 | ||
540 | /* we want to get all but last byte, because the TX_ERROR IRQ is used | |
541 | * to inidicate error ACK on the address, and negative ack on the last | |
542 | * received byte, so to not mix them receive all but last. | |
543 | * In the case where there is only one byte to receive | |
544 | * we can check if ERROR and RX full is set at the same time | |
545 | */ | |
546 | rx_watermark = msg->len; | |
547 | if (rx_watermark > IIC_RX_FIFO_DEPTH) | |
548 | rx_watermark = IIC_RX_FIFO_DEPTH; | |
549 | xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rx_watermark - 1); | |
550 | ||
551 | if (!(msg->flags & I2C_M_NOSTART)) | |
552 | /* write the address */ | |
553 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, | |
554 | (msg->addr << 1) | XIIC_READ_OPERATION | | |
555 | XIIC_TX_DYN_START_MASK); | |
556 | ||
557 | xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); | |
558 | ||
559 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, | |
560 | msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0)); | |
561 | if (i2c->nmsgs == 1) | |
562 | /* very last, enable bus not busy as well */ | |
563 | xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); | |
564 | ||
565 | /* the message is tx:ed */ | |
566 | i2c->tx_pos = msg->len; | |
567 | } | |
568 | ||
569 | static void xiic_start_send(struct xiic_i2c *i2c) | |
570 | { | |
571 | struct i2c_msg *msg = i2c->tx_msg; | |
572 | ||
573 | xiic_irq_clr(i2c, XIIC_INTR_TX_ERROR_MASK); | |
574 | ||
f1e9f89a KA |
575 | dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d", |
576 | __func__, msg, msg->len); | |
577 | dev_dbg(i2c->adap.dev.parent, "%s entry, ISR: 0x%x, CR: 0x%x\n", | |
578 | __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), | |
e1d5b659 RR |
579 | xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); |
580 | ||
581 | if (!(msg->flags & I2C_M_NOSTART)) { | |
582 | /* write the address */ | |
583 | u16 data = ((msg->addr << 1) & 0xfe) | XIIC_WRITE_OPERATION | | |
584 | XIIC_TX_DYN_START_MASK; | |
585 | if ((i2c->nmsgs == 1) && msg->len == 0) | |
586 | /* no data and last message -> add STOP */ | |
587 | data |= XIIC_TX_DYN_STOP_MASK; | |
588 | ||
589 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); | |
590 | } | |
591 | ||
592 | xiic_fill_tx_fifo(i2c); | |
593 | ||
594 | /* Clear any pending Tx empty, Tx Error and then enable them. */ | |
595 | xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK | | |
596 | XIIC_INTR_BNB_MASK); | |
597 | } | |
598 | ||
599 | static irqreturn_t xiic_isr(int irq, void *dev_id) | |
600 | { | |
601 | struct xiic_i2c *i2c = dev_id; | |
fcc2fac6 SD |
602 | u32 pend, isr, ier; |
603 | irqreturn_t ret = IRQ_NONE; | |
604 | /* Do not processes a devices interrupts if the device has no | |
605 | * interrupts pending | |
606 | */ | |
e1d5b659 RR |
607 | |
608 | dev_dbg(i2c->adap.dev.parent, "%s entry\n", __func__); | |
609 | ||
fcc2fac6 SD |
610 | isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); |
611 | ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
612 | pend = isr & ier; | |
613 | if (pend) | |
614 | ret = IRQ_WAKE_THREAD; | |
e1d5b659 | 615 | |
fcc2fac6 | 616 | return ret; |
e1d5b659 RR |
617 | } |
618 | ||
619 | static void __xiic_start_xfer(struct xiic_i2c *i2c) | |
620 | { | |
621 | int first = 1; | |
622 | int fifo_space = xiic_tx_fifo_space(i2c); | |
623 | dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n", | |
624 | __func__, i2c->tx_msg, fifo_space); | |
625 | ||
626 | if (!i2c->tx_msg) | |
627 | return; | |
628 | ||
629 | i2c->rx_pos = 0; | |
630 | i2c->tx_pos = 0; | |
631 | i2c->state = STATE_START; | |
632 | while ((fifo_space >= 2) && (first || (i2c->nmsgs > 1))) { | |
633 | if (!first) { | |
634 | i2c->nmsgs--; | |
635 | i2c->tx_msg++; | |
636 | i2c->tx_pos = 0; | |
637 | } else | |
638 | first = 0; | |
639 | ||
640 | if (i2c->tx_msg->flags & I2C_M_RD) { | |
641 | /* we dont date putting several reads in the FIFO */ | |
642 | xiic_start_recv(i2c); | |
643 | return; | |
644 | } else { | |
645 | xiic_start_send(i2c); | |
646 | if (xiic_tx_space(i2c) != 0) { | |
647 | /* the message could not be completely sent */ | |
648 | break; | |
649 | } | |
650 | } | |
651 | ||
652 | fifo_space = xiic_tx_fifo_space(i2c); | |
653 | } | |
654 | ||
655 | /* there are more messages or the current one could not be completely | |
656 | * put into the FIFO, also enable the half empty interrupt | |
657 | */ | |
658 | if (i2c->nmsgs > 1 || xiic_tx_space(i2c)) | |
659 | xiic_irq_clr_en(i2c, XIIC_INTR_TX_HALF_MASK); | |
660 | ||
661 | } | |
662 | ||
663 | static void xiic_start_xfer(struct xiic_i2c *i2c) | |
664 | { | |
9656eeeb LPC |
665 | spin_lock(&i2c->lock); |
666 | xiic_reinit(i2c); | |
e1d5b659 | 667 | __xiic_start_xfer(i2c); |
d0fe5258 | 668 | spin_unlock(&i2c->lock); |
e1d5b659 RR |
669 | } |
670 | ||
671 | static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
672 | { | |
673 | struct xiic_i2c *i2c = i2c_get_adapdata(adap); | |
674 | int err; | |
675 | ||
676 | dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__, | |
677 | xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)); | |
678 | ||
679 | err = xiic_busy(i2c); | |
680 | if (err) | |
681 | return err; | |
682 | ||
683 | i2c->tx_msg = msgs; | |
684 | i2c->nmsgs = num; | |
685 | ||
686 | xiic_start_xfer(i2c); | |
687 | ||
688 | if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) || | |
689 | (i2c->state == STATE_DONE), HZ)) | |
690 | return (i2c->state == STATE_DONE) ? num : -EIO; | |
691 | else { | |
692 | i2c->tx_msg = NULL; | |
693 | i2c->rx_msg = NULL; | |
694 | i2c->nmsgs = 0; | |
695 | return -ETIMEDOUT; | |
696 | } | |
697 | } | |
698 | ||
699 | static u32 xiic_func(struct i2c_adapter *adap) | |
700 | { | |
701 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; | |
702 | } | |
703 | ||
704 | static const struct i2c_algorithm xiic_algorithm = { | |
4db5beed WS |
705 | .master_xfer = xiic_xfer, |
706 | .functionality = xiic_func, | |
e1d5b659 RR |
707 | }; |
708 | ||
709 | static struct i2c_adapter xiic_adapter = { | |
4db5beed WS |
710 | .owner = THIS_MODULE, |
711 | .name = DRIVER_NAME, | |
712 | .class = I2C_CLASS_DEPRECATED, | |
713 | .algo = &xiic_algorithm, | |
e1d5b659 RR |
714 | }; |
715 | ||
716 | ||
0b255e92 | 717 | static int xiic_i2c_probe(struct platform_device *pdev) |
e1d5b659 RR |
718 | { |
719 | struct xiic_i2c *i2c; | |
720 | struct xiic_i2c_platform_data *pdata; | |
721 | struct resource *res; | |
722 | int ret, irq; | |
723 | u8 i; | |
48ef3ca9 | 724 | u32 sr; |
e1d5b659 | 725 | |
168e722d KA |
726 | i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); |
727 | if (!i2c) | |
728 | return -ENOMEM; | |
729 | ||
e1d5b659 | 730 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
168e722d KA |
731 | i2c->base = devm_ioremap_resource(&pdev->dev, res); |
732 | if (IS_ERR(i2c->base)) | |
733 | return PTR_ERR(i2c->base); | |
e1d5b659 RR |
734 | |
735 | irq = platform_get_irq(pdev, 0); | |
736 | if (irq < 0) | |
168e722d | 737 | return irq; |
e1d5b659 | 738 | |
ab0dc7a8 | 739 | pdata = dev_get_platdata(&pdev->dev); |
e1d5b659 | 740 | |
e1d5b659 RR |
741 | /* hook up driver to tree */ |
742 | platform_set_drvdata(pdev, i2c); | |
743 | i2c->adap = xiic_adapter; | |
744 | i2c_set_adapdata(&i2c->adap, i2c); | |
745 | i2c->adap.dev.parent = &pdev->dev; | |
3ac0b337 | 746 | i2c->adap.dev.of_node = pdev->dev.of_node; |
e1d5b659 | 747 | |
e1d5b659 RR |
748 | spin_lock_init(&i2c->lock); |
749 | init_waitqueue_head(&i2c->wait); | |
168e722d | 750 | |
fcc2fac6 SD |
751 | ret = devm_request_threaded_irq(&pdev->dev, irq, xiic_isr, |
752 | xiic_process, IRQF_ONESHOT, | |
753 | pdev->name, i2c); | |
754 | ||
168e722d | 755 | if (ret < 0) { |
e1d5b659 | 756 | dev_err(&pdev->dev, "Cannot claim IRQ\n"); |
168e722d | 757 | return ret; |
e1d5b659 RR |
758 | } |
759 | ||
48ef3ca9 TG |
760 | /* |
761 | * Detect endianness | |
762 | * Try to reset the TX FIFO. Then check the EMPTY flag. If it is not | |
763 | * set, assume that the endianness was wrong and swap. | |
764 | */ | |
765 | i2c->endianness = LITTLE; | |
766 | xiic_setreg32(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK); | |
767 | /* Reset is cleared in xiic_reinit */ | |
768 | sr = xiic_getreg32(i2c, XIIC_SR_REG_OFFSET); | |
769 | if (!(sr & XIIC_SR_TX_FIFO_EMPTY_MASK)) | |
770 | i2c->endianness = BIG; | |
771 | ||
617bdcbc MS |
772 | xiic_reinit(i2c); |
773 | ||
e1d5b659 RR |
774 | /* add i2c adapter to i2c tree */ |
775 | ret = i2c_add_adapter(&i2c->adap); | |
776 | if (ret) { | |
777 | dev_err(&pdev->dev, "Failed to add adapter\n"); | |
168e722d KA |
778 | xiic_deinit(i2c); |
779 | return ret; | |
e1d5b659 RR |
780 | } |
781 | ||
3ac0b337 LPC |
782 | if (pdata) { |
783 | /* add in known devices to the bus */ | |
784 | for (i = 0; i < pdata->num_devices; i++) | |
785 | i2c_new_device(&i2c->adap, pdata->devices + i); | |
786 | } | |
787 | ||
e1d5b659 | 788 | return 0; |
e1d5b659 RR |
789 | } |
790 | ||
0b255e92 | 791 | static int xiic_i2c_remove(struct platform_device *pdev) |
e1d5b659 RR |
792 | { |
793 | struct xiic_i2c *i2c = platform_get_drvdata(pdev); | |
e1d5b659 RR |
794 | |
795 | /* remove adapter & data */ | |
796 | i2c_del_adapter(&i2c->adap); | |
797 | ||
798 | xiic_deinit(i2c); | |
799 | ||
e1d5b659 RR |
800 | return 0; |
801 | } | |
802 | ||
3ac0b337 | 803 | #if defined(CONFIG_OF) |
0b255e92 | 804 | static const struct of_device_id xiic_of_match[] = { |
3ac0b337 LPC |
805 | { .compatible = "xlnx,xps-iic-2.00.a", }, |
806 | {}, | |
807 | }; | |
808 | MODULE_DEVICE_TABLE(of, xiic_of_match); | |
809 | #endif | |
810 | ||
e1d5b659 RR |
811 | static struct platform_driver xiic_i2c_driver = { |
812 | .probe = xiic_i2c_probe, | |
0b255e92 | 813 | .remove = xiic_i2c_remove, |
e1d5b659 | 814 | .driver = { |
e1d5b659 | 815 | .name = DRIVER_NAME, |
3ac0b337 | 816 | .of_match_table = of_match_ptr(xiic_of_match), |
e1d5b659 RR |
817 | }, |
818 | }; | |
819 | ||
a3664b51 | 820 | module_platform_driver(xiic_i2c_driver); |
e1d5b659 RR |
821 | |
822 | MODULE_AUTHOR("info@mocean-labs.com"); | |
823 | MODULE_DESCRIPTION("Xilinx I2C bus driver"); | |
824 | MODULE_LICENSE("GPL v2"); | |
a3664b51 | 825 | MODULE_ALIAS("platform:"DRIVER_NAME); |