Commit | Line | Data |
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1802d0be | 1 | // SPDX-License-Identifier: GPL-2.0-only |
e1d5b659 RR |
2 | /* |
3 | * i2c-xiic.c | |
4 | * Copyright (c) 2002-2007 Xilinx Inc. | |
5 | * Copyright (c) 2009-2010 Intel Corporation | |
6 | * | |
e1d5b659 RR |
7 | * This code was implemented by Mocean Laboratories AB when porting linux |
8 | * to the automotive development board Russellville. The copyright holder | |
9 | * as seen in the header is Intel corporation. | |
10 | * Mocean Laboratories forked off the GNU/Linux platform work into a | |
25985edc | 11 | * separate company called Pelagicore AB, which committed the code to the |
e1d5b659 RR |
12 | * kernel. |
13 | */ | |
14 | ||
15 | /* Supports: | |
16 | * Xilinx IIC | |
17 | */ | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
e1d5b659 | 20 | #include <linux/errno.h> |
168e722d | 21 | #include <linux/err.h> |
02ca6c40 | 22 | #include <linux/delay.h> |
e1d5b659 RR |
23 | #include <linux/platform_device.h> |
24 | #include <linux/i2c.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/wait.h> | |
7072b75c | 27 | #include <linux/platform_data/i2c-xiic.h> |
e1d5b659 | 28 | #include <linux/io.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
4edd65e6 | 30 | #include <linux/of.h> |
36ecbcab SD |
31 | #include <linux/clk.h> |
32 | #include <linux/pm_runtime.h> | |
e1d5b659 RR |
33 | |
34 | #define DRIVER_NAME "xiic-i2c" | |
35 | ||
36 | enum xilinx_i2c_state { | |
37 | STATE_DONE, | |
38 | STATE_ERROR, | |
39 | STATE_START | |
40 | }; | |
41 | ||
48ef3ca9 TG |
42 | enum xiic_endian { |
43 | LITTLE, | |
44 | BIG | |
45 | }; | |
46 | ||
e1d5b659 RR |
47 | /** |
48 | * struct xiic_i2c - Internal representation of the XIIC I2C bus | |
49 | * @base: Memory base of the HW registers | |
50 | * @wait: Wait queue for callers | |
51 | * @adap: Kernel adapter representation | |
52 | * @tx_msg: Messages from above to be sent | |
53 | * @lock: Mutual exclusion | |
54 | * @tx_pos: Current pos in TX message | |
55 | * @nmsgs: Number of messages in tx_msg | |
56 | * @state: See STATE_ | |
57 | * @rx_msg: Current RX message | |
58 | * @rx_pos: Position within current RX message | |
bea6ff02 | 59 | * @endianness: big/little-endian byte order |
e1d5b659 RR |
60 | */ |
61 | struct xiic_i2c { | |
36ecbcab | 62 | struct device *dev; |
e1d5b659 RR |
63 | void __iomem *base; |
64 | wait_queue_head_t wait; | |
65 | struct i2c_adapter adap; | |
66 | struct i2c_msg *tx_msg; | |
77c68019 | 67 | struct mutex lock; |
f1e9f89a | 68 | unsigned int tx_pos; |
e1d5b659 RR |
69 | unsigned int nmsgs; |
70 | enum xilinx_i2c_state state; | |
71 | struct i2c_msg *rx_msg; | |
72 | int rx_pos; | |
48ef3ca9 | 73 | enum xiic_endian endianness; |
36ecbcab | 74 | struct clk *clk; |
e1d5b659 RR |
75 | }; |
76 | ||
77 | ||
78 | #define XIIC_MSB_OFFSET 0 | |
79 | #define XIIC_REG_OFFSET (0x100+XIIC_MSB_OFFSET) | |
80 | ||
81 | /* | |
82 | * Register offsets in bytes from RegisterBase. Three is added to the | |
83 | * base offset to access LSB (IBM style) of the word | |
84 | */ | |
85 | #define XIIC_CR_REG_OFFSET (0x00+XIIC_REG_OFFSET) /* Control Register */ | |
86 | #define XIIC_SR_REG_OFFSET (0x04+XIIC_REG_OFFSET) /* Status Register */ | |
87 | #define XIIC_DTR_REG_OFFSET (0x08+XIIC_REG_OFFSET) /* Data Tx Register */ | |
88 | #define XIIC_DRR_REG_OFFSET (0x0C+XIIC_REG_OFFSET) /* Data Rx Register */ | |
89 | #define XIIC_ADR_REG_OFFSET (0x10+XIIC_REG_OFFSET) /* Address Register */ | |
90 | #define XIIC_TFO_REG_OFFSET (0x14+XIIC_REG_OFFSET) /* Tx FIFO Occupancy */ | |
91 | #define XIIC_RFO_REG_OFFSET (0x18+XIIC_REG_OFFSET) /* Rx FIFO Occupancy */ | |
92 | #define XIIC_TBA_REG_OFFSET (0x1C+XIIC_REG_OFFSET) /* 10 Bit Address reg */ | |
93 | #define XIIC_RFD_REG_OFFSET (0x20+XIIC_REG_OFFSET) /* Rx FIFO Depth reg */ | |
94 | #define XIIC_GPO_REG_OFFSET (0x24+XIIC_REG_OFFSET) /* Output Register */ | |
95 | ||
96 | /* Control Register masks */ | |
97 | #define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */ | |
98 | #define XIIC_CR_TX_FIFO_RESET_MASK 0x02 /* Transmit FIFO reset=1 */ | |
99 | #define XIIC_CR_MSMS_MASK 0x04 /* Master starts Txing=1 */ | |
100 | #define XIIC_CR_DIR_IS_TX_MASK 0x08 /* Dir of tx. Txing=1 */ | |
101 | #define XIIC_CR_NO_ACK_MASK 0x10 /* Tx Ack. NO ack = 1 */ | |
102 | #define XIIC_CR_REPEATED_START_MASK 0x20 /* Repeated start = 1 */ | |
103 | #define XIIC_CR_GENERAL_CALL_MASK 0x40 /* Gen Call enabled = 1 */ | |
104 | ||
105 | /* Status Register masks */ | |
106 | #define XIIC_SR_GEN_CALL_MASK 0x01 /* 1=a mstr issued a GC */ | |
107 | #define XIIC_SR_ADDR_AS_SLAVE_MASK 0x02 /* 1=when addr as slave */ | |
108 | #define XIIC_SR_BUS_BUSY_MASK 0x04 /* 1 = bus is busy */ | |
109 | #define XIIC_SR_MSTR_RDING_SLAVE_MASK 0x08 /* 1=Dir: mstr <-- slave */ | |
110 | #define XIIC_SR_TX_FIFO_FULL_MASK 0x10 /* 1 = Tx FIFO full */ | |
111 | #define XIIC_SR_RX_FIFO_FULL_MASK 0x20 /* 1 = Rx FIFO full */ | |
112 | #define XIIC_SR_RX_FIFO_EMPTY_MASK 0x40 /* 1 = Rx FIFO empty */ | |
113 | #define XIIC_SR_TX_FIFO_EMPTY_MASK 0x80 /* 1 = Tx FIFO empty */ | |
114 | ||
115 | /* Interrupt Status Register masks Interrupt occurs when... */ | |
116 | #define XIIC_INTR_ARB_LOST_MASK 0x01 /* 1 = arbitration lost */ | |
117 | #define XIIC_INTR_TX_ERROR_MASK 0x02 /* 1=Tx error/msg complete */ | |
118 | #define XIIC_INTR_TX_EMPTY_MASK 0x04 /* 1 = Tx FIFO/reg empty */ | |
119 | #define XIIC_INTR_RX_FULL_MASK 0x08 /* 1=Rx FIFO/reg=OCY level */ | |
120 | #define XIIC_INTR_BNB_MASK 0x10 /* 1 = Bus not busy */ | |
121 | #define XIIC_INTR_AAS_MASK 0x20 /* 1 = when addr as slave */ | |
122 | #define XIIC_INTR_NAAS_MASK 0x40 /* 1 = not addr as slave */ | |
123 | #define XIIC_INTR_TX_HALF_MASK 0x80 /* 1 = TX FIFO half empty */ | |
124 | ||
125 | /* The following constants specify the depth of the FIFOs */ | |
126 | #define IIC_RX_FIFO_DEPTH 16 /* Rx fifo capacity */ | |
127 | #define IIC_TX_FIFO_DEPTH 16 /* Tx fifo capacity */ | |
128 | ||
129 | /* The following constants specify groups of interrupts that are typically | |
130 | * enabled or disables at the same time | |
131 | */ | |
132 | #define XIIC_TX_INTERRUPTS \ | |
133 | (XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK) | |
134 | ||
135 | #define XIIC_TX_RX_INTERRUPTS (XIIC_INTR_RX_FULL_MASK | XIIC_TX_INTERRUPTS) | |
136 | ||
e1d5b659 RR |
137 | /* |
138 | * Tx Fifo upper bit masks. | |
139 | */ | |
140 | #define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */ | |
141 | #define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */ | |
142 | ||
143 | /* | |
144 | * The following constants define the register offsets for the Interrupt | |
145 | * registers. There are some holes in the memory map for reserved addresses | |
146 | * to allow other registers to be added and still match the memory map of the | |
147 | * interrupt controller registers | |
148 | */ | |
149 | #define XIIC_DGIER_OFFSET 0x1C /* Device Global Interrupt Enable Register */ | |
150 | #define XIIC_IISR_OFFSET 0x20 /* Interrupt Status Register */ | |
151 | #define XIIC_IIER_OFFSET 0x28 /* Interrupt Enable Register */ | |
152 | #define XIIC_RESETR_OFFSET 0x40 /* Reset Register */ | |
153 | ||
154 | #define XIIC_RESET_MASK 0xAUL | |
155 | ||
36ecbcab | 156 | #define XIIC_PM_TIMEOUT 1000 /* ms */ |
e1d5b659 RR |
157 | /* |
158 | * The following constant is used for the device global interrupt enable | |
159 | * register, to enable all interrupts for the device, this is the only bit | |
160 | * in the register | |
161 | */ | |
162 | #define XIIC_GINTR_ENABLE_MASK 0x80000000UL | |
163 | ||
164 | #define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos) | |
165 | #define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos) | |
166 | ||
167 | static void xiic_start_xfer(struct xiic_i2c *i2c); | |
168 | static void __xiic_start_xfer(struct xiic_i2c *i2c); | |
169 | ||
48ef3ca9 TG |
170 | /* |
171 | * For the register read and write functions, a little-endian and big-endian | |
172 | * version are necessary. Endianness is detected during the probe function. | |
173 | * Only the least significant byte [doublet] of the register are ever | |
174 | * accessed. This requires an offset of 3 [2] from the base address for | |
175 | * big-endian systems. | |
176 | */ | |
177 | ||
e1d5b659 RR |
178 | static inline void xiic_setreg8(struct xiic_i2c *i2c, int reg, u8 value) |
179 | { | |
48ef3ca9 TG |
180 | if (i2c->endianness == LITTLE) |
181 | iowrite8(value, i2c->base + reg); | |
182 | else | |
183 | iowrite8(value, i2c->base + reg + 3); | |
e1d5b659 RR |
184 | } |
185 | ||
186 | static inline u8 xiic_getreg8(struct xiic_i2c *i2c, int reg) | |
187 | { | |
48ef3ca9 TG |
188 | u8 ret; |
189 | ||
190 | if (i2c->endianness == LITTLE) | |
191 | ret = ioread8(i2c->base + reg); | |
192 | else | |
193 | ret = ioread8(i2c->base + reg + 3); | |
194 | return ret; | |
e1d5b659 RR |
195 | } |
196 | ||
197 | static inline void xiic_setreg16(struct xiic_i2c *i2c, int reg, u16 value) | |
198 | { | |
48ef3ca9 TG |
199 | if (i2c->endianness == LITTLE) |
200 | iowrite16(value, i2c->base + reg); | |
201 | else | |
202 | iowrite16be(value, i2c->base + reg + 2); | |
e1d5b659 RR |
203 | } |
204 | ||
205 | static inline void xiic_setreg32(struct xiic_i2c *i2c, int reg, int value) | |
206 | { | |
48ef3ca9 TG |
207 | if (i2c->endianness == LITTLE) |
208 | iowrite32(value, i2c->base + reg); | |
209 | else | |
210 | iowrite32be(value, i2c->base + reg); | |
e1d5b659 RR |
211 | } |
212 | ||
213 | static inline int xiic_getreg32(struct xiic_i2c *i2c, int reg) | |
214 | { | |
48ef3ca9 TG |
215 | u32 ret; |
216 | ||
217 | if (i2c->endianness == LITTLE) | |
218 | ret = ioread32(i2c->base + reg); | |
219 | else | |
220 | ret = ioread32be(i2c->base + reg); | |
221 | return ret; | |
e1d5b659 RR |
222 | } |
223 | ||
224 | static inline void xiic_irq_dis(struct xiic_i2c *i2c, u32 mask) | |
225 | { | |
226 | u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
227 | xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier & ~mask); | |
228 | } | |
229 | ||
230 | static inline void xiic_irq_en(struct xiic_i2c *i2c, u32 mask) | |
231 | { | |
232 | u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
233 | xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier | mask); | |
234 | } | |
235 | ||
236 | static inline void xiic_irq_clr(struct xiic_i2c *i2c, u32 mask) | |
237 | { | |
238 | u32 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); | |
239 | xiic_setreg32(i2c, XIIC_IISR_OFFSET, isr & mask); | |
240 | } | |
241 | ||
242 | static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask) | |
243 | { | |
244 | xiic_irq_clr(i2c, mask); | |
245 | xiic_irq_en(i2c, mask); | |
246 | } | |
247 | ||
248 | static void xiic_clear_rx_fifo(struct xiic_i2c *i2c) | |
249 | { | |
250 | u8 sr; | |
251 | for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET); | |
252 | !(sr & XIIC_SR_RX_FIFO_EMPTY_MASK); | |
253 | sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)) | |
254 | xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); | |
255 | } | |
256 | ||
257 | static void xiic_reinit(struct xiic_i2c *i2c) | |
258 | { | |
259 | xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK); | |
260 | ||
261 | /* Set receive Fifo depth to maximum (zero based). */ | |
262 | xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1); | |
263 | ||
264 | /* Reset Tx Fifo. */ | |
265 | xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK); | |
266 | ||
267 | /* Enable IIC Device, remove Tx Fifo reset & disable general call. */ | |
268 | xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK); | |
269 | ||
270 | /* make sure RX fifo is empty */ | |
271 | xiic_clear_rx_fifo(i2c); | |
272 | ||
273 | /* Enable interrupts */ | |
274 | xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); | |
275 | ||
542e2a9b | 276 | xiic_irq_clr_en(i2c, XIIC_INTR_ARB_LOST_MASK); |
e1d5b659 RR |
277 | } |
278 | ||
279 | static void xiic_deinit(struct xiic_i2c *i2c) | |
280 | { | |
281 | u8 cr; | |
282 | ||
283 | xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK); | |
284 | ||
285 | /* Disable IIC Device. */ | |
286 | cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); | |
287 | xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK); | |
288 | } | |
289 | ||
290 | static void xiic_read_rx(struct xiic_i2c *i2c) | |
291 | { | |
292 | u8 bytes_in_fifo; | |
293 | int i; | |
294 | ||
295 | bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1; | |
296 | ||
f1e9f89a KA |
297 | dev_dbg(i2c->adap.dev.parent, |
298 | "%s entry, bytes in fifo: %d, msg: %d, SR: 0x%x, CR: 0x%x\n", | |
e1d5b659 RR |
299 | __func__, bytes_in_fifo, xiic_rx_space(i2c), |
300 | xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), | |
301 | xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); | |
302 | ||
303 | if (bytes_in_fifo > xiic_rx_space(i2c)) | |
304 | bytes_in_fifo = xiic_rx_space(i2c); | |
305 | ||
306 | for (i = 0; i < bytes_in_fifo; i++) | |
307 | i2c->rx_msg->buf[i2c->rx_pos++] = | |
308 | xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); | |
309 | ||
310 | xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, | |
311 | (xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ? | |
312 | IIC_RX_FIFO_DEPTH - 1 : xiic_rx_space(i2c) - 1); | |
313 | } | |
314 | ||
315 | static int xiic_tx_fifo_space(struct xiic_i2c *i2c) | |
316 | { | |
317 | /* return the actual space left in the FIFO */ | |
318 | return IIC_TX_FIFO_DEPTH - xiic_getreg8(i2c, XIIC_TFO_REG_OFFSET) - 1; | |
319 | } | |
320 | ||
321 | static void xiic_fill_tx_fifo(struct xiic_i2c *i2c) | |
322 | { | |
323 | u8 fifo_space = xiic_tx_fifo_space(i2c); | |
324 | int len = xiic_tx_space(i2c); | |
325 | ||
326 | len = (len > fifo_space) ? fifo_space : len; | |
327 | ||
328 | dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n", | |
329 | __func__, len, fifo_space); | |
330 | ||
331 | while (len--) { | |
332 | u16 data = i2c->tx_msg->buf[i2c->tx_pos++]; | |
333 | if ((xiic_tx_space(i2c) == 0) && (i2c->nmsgs == 1)) { | |
334 | /* last message in transfer -> STOP */ | |
335 | data |= XIIC_TX_DYN_STOP_MASK; | |
336 | dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__); | |
c39e8e43 SF |
337 | } |
338 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); | |
e1d5b659 RR |
339 | } |
340 | } | |
341 | ||
342 | static void xiic_wakeup(struct xiic_i2c *i2c, int code) | |
343 | { | |
344 | i2c->tx_msg = NULL; | |
345 | i2c->rx_msg = NULL; | |
346 | i2c->nmsgs = 0; | |
347 | i2c->state = code; | |
348 | wake_up(&i2c->wait); | |
349 | } | |
350 | ||
fcc2fac6 | 351 | static irqreturn_t xiic_process(int irq, void *dev_id) |
e1d5b659 | 352 | { |
fcc2fac6 | 353 | struct xiic_i2c *i2c = dev_id; |
e1d5b659 RR |
354 | u32 pend, isr, ier; |
355 | u32 clr = 0; | |
356 | ||
357 | /* Get the interrupt Status from the IPIF. There is no clearing of | |
358 | * interrupts in the IPIF. Interrupts must be cleared at the source. | |
359 | * To find which interrupts are pending; AND interrupts pending with | |
360 | * interrupts masked. | |
361 | */ | |
77c68019 | 362 | mutex_lock(&i2c->lock); |
e1d5b659 RR |
363 | isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); |
364 | ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
365 | pend = isr & ier; | |
366 | ||
f1e9f89a KA |
367 | dev_dbg(i2c->adap.dev.parent, "%s: IER: 0x%x, ISR: 0x%x, pend: 0x%x\n", |
368 | __func__, ier, isr, pend); | |
369 | dev_dbg(i2c->adap.dev.parent, "%s: SR: 0x%x, msg: %p, nmsgs: %d\n", | |
370 | __func__, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), | |
e1d5b659 RR |
371 | i2c->tx_msg, i2c->nmsgs); |
372 | ||
e1d5b659 RR |
373 | |
374 | /* Service requesting interrupt */ | |
375 | if ((pend & XIIC_INTR_ARB_LOST_MASK) || | |
376 | ((pend & XIIC_INTR_TX_ERROR_MASK) && | |
377 | !(pend & XIIC_INTR_RX_FULL_MASK))) { | |
378 | /* bus arbritration lost, or... | |
379 | * Transmit error _OR_ RX completed | |
380 | * if this happens when RX_FULL is not set | |
381 | * this is probably a TX error | |
382 | */ | |
383 | ||
384 | dev_dbg(i2c->adap.dev.parent, "%s error\n", __func__); | |
385 | ||
386 | /* dynamic mode seem to suffer from problems if we just flushes | |
387 | * fifos and the next message is a TX with len 0 (only addr) | |
388 | * reset the IP instead of just flush fifos | |
389 | */ | |
390 | xiic_reinit(i2c); | |
391 | ||
6b0c8dc3 SD |
392 | if (i2c->rx_msg) |
393 | xiic_wakeup(i2c, STATE_ERROR); | |
e1d5b659 RR |
394 | if (i2c->tx_msg) |
395 | xiic_wakeup(i2c, STATE_ERROR); | |
7f9906bd SD |
396 | } |
397 | if (pend & XIIC_INTR_RX_FULL_MASK) { | |
e1d5b659 RR |
398 | /* Receive register/FIFO is full */ |
399 | ||
7f9906bd | 400 | clr |= XIIC_INTR_RX_FULL_MASK; |
e1d5b659 RR |
401 | if (!i2c->rx_msg) { |
402 | dev_dbg(i2c->adap.dev.parent, | |
1ee7cdbf | 403 | "%s unexpected RX IRQ\n", __func__); |
e1d5b659 RR |
404 | xiic_clear_rx_fifo(i2c); |
405 | goto out; | |
406 | } | |
407 | ||
408 | xiic_read_rx(i2c); | |
409 | if (xiic_rx_space(i2c) == 0) { | |
410 | /* this is the last part of the message */ | |
411 | i2c->rx_msg = NULL; | |
412 | ||
413 | /* also clear TX error if there (RX complete) */ | |
414 | clr |= (isr & XIIC_INTR_TX_ERROR_MASK); | |
415 | ||
416 | dev_dbg(i2c->adap.dev.parent, | |
417 | "%s end of message, nmsgs: %d\n", | |
418 | __func__, i2c->nmsgs); | |
419 | ||
420 | /* send next message if this wasn't the last, | |
421 | * otherwise the transfer will be finialise when | |
422 | * receiving the bus not busy interrupt | |
423 | */ | |
424 | if (i2c->nmsgs > 1) { | |
425 | i2c->nmsgs--; | |
426 | i2c->tx_msg++; | |
427 | dev_dbg(i2c->adap.dev.parent, | |
428 | "%s will start next...\n", __func__); | |
429 | ||
430 | __xiic_start_xfer(i2c); | |
431 | } | |
432 | } | |
7f9906bd SD |
433 | } |
434 | if (pend & XIIC_INTR_BNB_MASK) { | |
e1d5b659 | 435 | /* IIC bus has transitioned to not busy */ |
7f9906bd | 436 | clr |= XIIC_INTR_BNB_MASK; |
e1d5b659 RR |
437 | |
438 | /* The bus is not busy, disable BusNotBusy interrupt */ | |
439 | xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK); | |
440 | ||
441 | if (!i2c->tx_msg) | |
442 | goto out; | |
443 | ||
444 | if ((i2c->nmsgs == 1) && !i2c->rx_msg && | |
445 | xiic_tx_space(i2c) == 0) | |
446 | xiic_wakeup(i2c, STATE_DONE); | |
447 | else | |
448 | xiic_wakeup(i2c, STATE_ERROR); | |
7f9906bd SD |
449 | } |
450 | if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) { | |
d36b6910 | 451 | /* Transmit register/FIFO is empty or ½ empty */ |
e1d5b659 | 452 | |
7f9906bd SD |
453 | clr |= (pend & |
454 | (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)); | |
e1d5b659 RR |
455 | |
456 | if (!i2c->tx_msg) { | |
457 | dev_dbg(i2c->adap.dev.parent, | |
1ee7cdbf | 458 | "%s unexpected TX IRQ\n", __func__); |
e1d5b659 RR |
459 | goto out; |
460 | } | |
461 | ||
462 | xiic_fill_tx_fifo(i2c); | |
463 | ||
464 | /* current message sent and there is space in the fifo */ | |
465 | if (!xiic_tx_space(i2c) && xiic_tx_fifo_space(i2c) >= 2) { | |
466 | dev_dbg(i2c->adap.dev.parent, | |
467 | "%s end of message sent, nmsgs: %d\n", | |
468 | __func__, i2c->nmsgs); | |
469 | if (i2c->nmsgs > 1) { | |
470 | i2c->nmsgs--; | |
471 | i2c->tx_msg++; | |
472 | __xiic_start_xfer(i2c); | |
473 | } else { | |
474 | xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK); | |
475 | ||
476 | dev_dbg(i2c->adap.dev.parent, | |
477 | "%s Got TX IRQ but no more to do...\n", | |
478 | __func__); | |
479 | } | |
480 | } else if (!xiic_tx_space(i2c) && (i2c->nmsgs == 1)) | |
481 | /* current frame is sent and is last, | |
482 | * make sure to disable tx half | |
483 | */ | |
484 | xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK); | |
e1d5b659 RR |
485 | } |
486 | out: | |
487 | dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr); | |
488 | ||
489 | xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr); | |
77c68019 | 490 | mutex_unlock(&i2c->lock); |
fcc2fac6 | 491 | return IRQ_HANDLED; |
e1d5b659 RR |
492 | } |
493 | ||
494 | static int xiic_bus_busy(struct xiic_i2c *i2c) | |
495 | { | |
496 | u8 sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET); | |
497 | ||
498 | return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0; | |
499 | } | |
500 | ||
501 | static int xiic_busy(struct xiic_i2c *i2c) | |
502 | { | |
503 | int tries = 3; | |
504 | int err; | |
505 | ||
506 | if (i2c->tx_msg) | |
507 | return -EBUSY; | |
508 | ||
509 | /* for instance if previous transfer was terminated due to TX error | |
510 | * it might be that the bus is on it's way to become available | |
511 | * give it at most 3 ms to wake | |
512 | */ | |
513 | err = xiic_bus_busy(i2c); | |
514 | while (err && tries--) { | |
b33aa252 | 515 | msleep(1); |
e1d5b659 RR |
516 | err = xiic_bus_busy(i2c); |
517 | } | |
518 | ||
519 | return err; | |
520 | } | |
521 | ||
522 | static void xiic_start_recv(struct xiic_i2c *i2c) | |
523 | { | |
524 | u8 rx_watermark; | |
525 | struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg; | |
ae7304c3 | 526 | unsigned long flags; |
e1d5b659 RR |
527 | |
528 | /* Clear and enable Rx full interrupt. */ | |
529 | xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK); | |
530 | ||
531 | /* we want to get all but last byte, because the TX_ERROR IRQ is used | |
532 | * to inidicate error ACK on the address, and negative ack on the last | |
533 | * received byte, so to not mix them receive all but last. | |
534 | * In the case where there is only one byte to receive | |
535 | * we can check if ERROR and RX full is set at the same time | |
536 | */ | |
537 | rx_watermark = msg->len; | |
538 | if (rx_watermark > IIC_RX_FIFO_DEPTH) | |
539 | rx_watermark = IIC_RX_FIFO_DEPTH; | |
540 | xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rx_watermark - 1); | |
541 | ||
ae7304c3 | 542 | local_irq_save(flags); |
e1d5b659 RR |
543 | if (!(msg->flags & I2C_M_NOSTART)) |
544 | /* write the address */ | |
545 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, | |
30a64757 | 546 | i2c_8bit_addr_from_msg(msg) | XIIC_TX_DYN_START_MASK); |
e1d5b659 RR |
547 | |
548 | xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); | |
549 | ||
550 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, | |
551 | msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0)); | |
ae7304c3 SD |
552 | local_irq_restore(flags); |
553 | ||
e1d5b659 RR |
554 | if (i2c->nmsgs == 1) |
555 | /* very last, enable bus not busy as well */ | |
556 | xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); | |
557 | ||
558 | /* the message is tx:ed */ | |
559 | i2c->tx_pos = msg->len; | |
560 | } | |
561 | ||
562 | static void xiic_start_send(struct xiic_i2c *i2c) | |
563 | { | |
564 | struct i2c_msg *msg = i2c->tx_msg; | |
565 | ||
566 | xiic_irq_clr(i2c, XIIC_INTR_TX_ERROR_MASK); | |
567 | ||
f1e9f89a KA |
568 | dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d", |
569 | __func__, msg, msg->len); | |
570 | dev_dbg(i2c->adap.dev.parent, "%s entry, ISR: 0x%x, CR: 0x%x\n", | |
571 | __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), | |
e1d5b659 RR |
572 | xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); |
573 | ||
574 | if (!(msg->flags & I2C_M_NOSTART)) { | |
575 | /* write the address */ | |
30a64757 | 576 | u16 data = i2c_8bit_addr_from_msg(msg) | |
e1d5b659 RR |
577 | XIIC_TX_DYN_START_MASK; |
578 | if ((i2c->nmsgs == 1) && msg->len == 0) | |
579 | /* no data and last message -> add STOP */ | |
580 | data |= XIIC_TX_DYN_STOP_MASK; | |
581 | ||
582 | xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); | |
583 | } | |
584 | ||
585 | xiic_fill_tx_fifo(i2c); | |
586 | ||
587 | /* Clear any pending Tx empty, Tx Error and then enable them. */ | |
588 | xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK | | |
589 | XIIC_INTR_BNB_MASK); | |
590 | } | |
591 | ||
592 | static irqreturn_t xiic_isr(int irq, void *dev_id) | |
593 | { | |
594 | struct xiic_i2c *i2c = dev_id; | |
fcc2fac6 SD |
595 | u32 pend, isr, ier; |
596 | irqreturn_t ret = IRQ_NONE; | |
597 | /* Do not processes a devices interrupts if the device has no | |
598 | * interrupts pending | |
599 | */ | |
e1d5b659 RR |
600 | |
601 | dev_dbg(i2c->adap.dev.parent, "%s entry\n", __func__); | |
602 | ||
fcc2fac6 SD |
603 | isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); |
604 | ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); | |
605 | pend = isr & ier; | |
606 | if (pend) | |
607 | ret = IRQ_WAKE_THREAD; | |
e1d5b659 | 608 | |
fcc2fac6 | 609 | return ret; |
e1d5b659 RR |
610 | } |
611 | ||
612 | static void __xiic_start_xfer(struct xiic_i2c *i2c) | |
613 | { | |
614 | int first = 1; | |
615 | int fifo_space = xiic_tx_fifo_space(i2c); | |
616 | dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n", | |
617 | __func__, i2c->tx_msg, fifo_space); | |
618 | ||
619 | if (!i2c->tx_msg) | |
620 | return; | |
621 | ||
622 | i2c->rx_pos = 0; | |
623 | i2c->tx_pos = 0; | |
624 | i2c->state = STATE_START; | |
625 | while ((fifo_space >= 2) && (first || (i2c->nmsgs > 1))) { | |
626 | if (!first) { | |
627 | i2c->nmsgs--; | |
628 | i2c->tx_msg++; | |
629 | i2c->tx_pos = 0; | |
630 | } else | |
631 | first = 0; | |
632 | ||
633 | if (i2c->tx_msg->flags & I2C_M_RD) { | |
634 | /* we dont date putting several reads in the FIFO */ | |
635 | xiic_start_recv(i2c); | |
636 | return; | |
637 | } else { | |
638 | xiic_start_send(i2c); | |
639 | if (xiic_tx_space(i2c) != 0) { | |
640 | /* the message could not be completely sent */ | |
641 | break; | |
642 | } | |
643 | } | |
644 | ||
645 | fifo_space = xiic_tx_fifo_space(i2c); | |
646 | } | |
647 | ||
648 | /* there are more messages or the current one could not be completely | |
649 | * put into the FIFO, also enable the half empty interrupt | |
650 | */ | |
651 | if (i2c->nmsgs > 1 || xiic_tx_space(i2c)) | |
652 | xiic_irq_clr_en(i2c, XIIC_INTR_TX_HALF_MASK); | |
653 | ||
654 | } | |
655 | ||
656 | static void xiic_start_xfer(struct xiic_i2c *i2c) | |
657 | { | |
77c68019 | 658 | mutex_lock(&i2c->lock); |
9656eeeb | 659 | xiic_reinit(i2c); |
e1d5b659 | 660 | __xiic_start_xfer(i2c); |
77c68019 | 661 | mutex_unlock(&i2c->lock); |
e1d5b659 RR |
662 | } |
663 | ||
664 | static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
665 | { | |
666 | struct xiic_i2c *i2c = i2c_get_adapdata(adap); | |
667 | int err; | |
668 | ||
669 | dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__, | |
670 | xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)); | |
671 | ||
36ecbcab SD |
672 | err = pm_runtime_get_sync(i2c->dev); |
673 | if (err < 0) | |
674 | return err; | |
675 | ||
e1d5b659 RR |
676 | err = xiic_busy(i2c); |
677 | if (err) | |
36ecbcab | 678 | goto out; |
e1d5b659 RR |
679 | |
680 | i2c->tx_msg = msgs; | |
681 | i2c->nmsgs = num; | |
682 | ||
683 | xiic_start_xfer(i2c); | |
684 | ||
685 | if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) || | |
36ecbcab SD |
686 | (i2c->state == STATE_DONE), HZ)) { |
687 | err = (i2c->state == STATE_DONE) ? num : -EIO; | |
688 | goto out; | |
689 | } else { | |
e1d5b659 RR |
690 | i2c->tx_msg = NULL; |
691 | i2c->rx_msg = NULL; | |
692 | i2c->nmsgs = 0; | |
36ecbcab SD |
693 | err = -ETIMEDOUT; |
694 | goto out; | |
e1d5b659 | 695 | } |
36ecbcab SD |
696 | out: |
697 | pm_runtime_mark_last_busy(i2c->dev); | |
698 | pm_runtime_put_autosuspend(i2c->dev); | |
699 | return err; | |
e1d5b659 RR |
700 | } |
701 | ||
702 | static u32 xiic_func(struct i2c_adapter *adap) | |
703 | { | |
704 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; | |
705 | } | |
706 | ||
707 | static const struct i2c_algorithm xiic_algorithm = { | |
4db5beed WS |
708 | .master_xfer = xiic_xfer, |
709 | .functionality = xiic_func, | |
e1d5b659 RR |
710 | }; |
711 | ||
329430cc | 712 | static const struct i2c_adapter xiic_adapter = { |
4db5beed WS |
713 | .owner = THIS_MODULE, |
714 | .name = DRIVER_NAME, | |
715 | .class = I2C_CLASS_DEPRECATED, | |
716 | .algo = &xiic_algorithm, | |
e1d5b659 RR |
717 | }; |
718 | ||
719 | ||
0b255e92 | 720 | static int xiic_i2c_probe(struct platform_device *pdev) |
e1d5b659 RR |
721 | { |
722 | struct xiic_i2c *i2c; | |
723 | struct xiic_i2c_platform_data *pdata; | |
724 | struct resource *res; | |
725 | int ret, irq; | |
726 | u8 i; | |
48ef3ca9 | 727 | u32 sr; |
e1d5b659 | 728 | |
168e722d KA |
729 | i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); |
730 | if (!i2c) | |
731 | return -ENOMEM; | |
732 | ||
e1d5b659 | 733 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
168e722d KA |
734 | i2c->base = devm_ioremap_resource(&pdev->dev, res); |
735 | if (IS_ERR(i2c->base)) | |
736 | return PTR_ERR(i2c->base); | |
e1d5b659 RR |
737 | |
738 | irq = platform_get_irq(pdev, 0); | |
739 | if (irq < 0) | |
168e722d | 740 | return irq; |
e1d5b659 | 741 | |
ab0dc7a8 | 742 | pdata = dev_get_platdata(&pdev->dev); |
e1d5b659 | 743 | |
e1d5b659 RR |
744 | /* hook up driver to tree */ |
745 | platform_set_drvdata(pdev, i2c); | |
746 | i2c->adap = xiic_adapter; | |
747 | i2c_set_adapdata(&i2c->adap, i2c); | |
748 | i2c->adap.dev.parent = &pdev->dev; | |
3ac0b337 | 749 | i2c->adap.dev.of_node = pdev->dev.of_node; |
e1d5b659 | 750 | |
77c68019 | 751 | mutex_init(&i2c->lock); |
e1d5b659 | 752 | init_waitqueue_head(&i2c->wait); |
168e722d | 753 | |
36ecbcab SD |
754 | i2c->clk = devm_clk_get(&pdev->dev, NULL); |
755 | if (IS_ERR(i2c->clk)) { | |
756 | dev_err(&pdev->dev, "input clock not found.\n"); | |
757 | return PTR_ERR(i2c->clk); | |
758 | } | |
759 | ret = clk_prepare_enable(i2c->clk); | |
760 | if (ret) { | |
761 | dev_err(&pdev->dev, "Unable to enable clock.\n"); | |
762 | return ret; | |
763 | } | |
764 | i2c->dev = &pdev->dev; | |
765 | pm_runtime_enable(i2c->dev); | |
766 | pm_runtime_set_autosuspend_delay(i2c->dev, XIIC_PM_TIMEOUT); | |
767 | pm_runtime_use_autosuspend(i2c->dev); | |
768 | pm_runtime_set_active(i2c->dev); | |
fcc2fac6 SD |
769 | ret = devm_request_threaded_irq(&pdev->dev, irq, xiic_isr, |
770 | xiic_process, IRQF_ONESHOT, | |
771 | pdev->name, i2c); | |
772 | ||
168e722d | 773 | if (ret < 0) { |
e1d5b659 | 774 | dev_err(&pdev->dev, "Cannot claim IRQ\n"); |
36ecbcab | 775 | goto err_clk_dis; |
e1d5b659 RR |
776 | } |
777 | ||
48ef3ca9 TG |
778 | /* |
779 | * Detect endianness | |
780 | * Try to reset the TX FIFO. Then check the EMPTY flag. If it is not | |
781 | * set, assume that the endianness was wrong and swap. | |
782 | */ | |
783 | i2c->endianness = LITTLE; | |
784 | xiic_setreg32(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK); | |
785 | /* Reset is cleared in xiic_reinit */ | |
786 | sr = xiic_getreg32(i2c, XIIC_SR_REG_OFFSET); | |
787 | if (!(sr & XIIC_SR_TX_FIFO_EMPTY_MASK)) | |
788 | i2c->endianness = BIG; | |
789 | ||
617bdcbc MS |
790 | xiic_reinit(i2c); |
791 | ||
e1d5b659 RR |
792 | /* add i2c adapter to i2c tree */ |
793 | ret = i2c_add_adapter(&i2c->adap); | |
794 | if (ret) { | |
168e722d | 795 | xiic_deinit(i2c); |
36ecbcab | 796 | goto err_clk_dis; |
e1d5b659 RR |
797 | } |
798 | ||
3ac0b337 LPC |
799 | if (pdata) { |
800 | /* add in known devices to the bus */ | |
801 | for (i = 0; i < pdata->num_devices; i++) | |
802 | i2c_new_device(&i2c->adap, pdata->devices + i); | |
803 | } | |
804 | ||
e1d5b659 | 805 | return 0; |
36ecbcab SD |
806 | |
807 | err_clk_dis: | |
808 | pm_runtime_set_suspended(&pdev->dev); | |
809 | pm_runtime_disable(&pdev->dev); | |
810 | clk_disable_unprepare(i2c->clk); | |
811 | return ret; | |
e1d5b659 RR |
812 | } |
813 | ||
0b255e92 | 814 | static int xiic_i2c_remove(struct platform_device *pdev) |
e1d5b659 RR |
815 | { |
816 | struct xiic_i2c *i2c = platform_get_drvdata(pdev); | |
36ecbcab | 817 | int ret; |
e1d5b659 RR |
818 | |
819 | /* remove adapter & data */ | |
820 | i2c_del_adapter(&i2c->adap); | |
821 | ||
36ecbcab SD |
822 | ret = clk_prepare_enable(i2c->clk); |
823 | if (ret) { | |
824 | dev_err(&pdev->dev, "Unable to enable clock.\n"); | |
825 | return ret; | |
826 | } | |
e1d5b659 | 827 | xiic_deinit(i2c); |
36ecbcab SD |
828 | clk_disable_unprepare(i2c->clk); |
829 | pm_runtime_disable(&pdev->dev); | |
e1d5b659 | 830 | |
e1d5b659 RR |
831 | return 0; |
832 | } | |
833 | ||
3ac0b337 | 834 | #if defined(CONFIG_OF) |
0b255e92 | 835 | static const struct of_device_id xiic_of_match[] = { |
3ac0b337 LPC |
836 | { .compatible = "xlnx,xps-iic-2.00.a", }, |
837 | {}, | |
838 | }; | |
839 | MODULE_DEVICE_TABLE(of, xiic_of_match); | |
840 | #endif | |
841 | ||
74d23319 | 842 | static int __maybe_unused xiic_i2c_runtime_suspend(struct device *dev) |
36ecbcab | 843 | { |
9242e72a | 844 | struct xiic_i2c *i2c = dev_get_drvdata(dev); |
36ecbcab SD |
845 | |
846 | clk_disable(i2c->clk); | |
847 | ||
848 | return 0; | |
849 | } | |
850 | ||
74d23319 | 851 | static int __maybe_unused xiic_i2c_runtime_resume(struct device *dev) |
36ecbcab | 852 | { |
9242e72a | 853 | struct xiic_i2c *i2c = dev_get_drvdata(dev); |
36ecbcab SD |
854 | int ret; |
855 | ||
856 | ret = clk_enable(i2c->clk); | |
857 | if (ret) { | |
858 | dev_err(dev, "Cannot enable clock.\n"); | |
859 | return ret; | |
860 | } | |
861 | ||
862 | return 0; | |
863 | } | |
864 | ||
865 | static const struct dev_pm_ops xiic_dev_pm_ops = { | |
74d23319 MF |
866 | SET_RUNTIME_PM_OPS(xiic_i2c_runtime_suspend, |
867 | xiic_i2c_runtime_resume, NULL) | |
36ecbcab | 868 | }; |
e1d5b659 RR |
869 | static struct platform_driver xiic_i2c_driver = { |
870 | .probe = xiic_i2c_probe, | |
0b255e92 | 871 | .remove = xiic_i2c_remove, |
e1d5b659 | 872 | .driver = { |
e1d5b659 | 873 | .name = DRIVER_NAME, |
3ac0b337 | 874 | .of_match_table = of_match_ptr(xiic_of_match), |
36ecbcab | 875 | .pm = &xiic_dev_pm_ops, |
e1d5b659 RR |
876 | }, |
877 | }; | |
878 | ||
a3664b51 | 879 | module_platform_driver(xiic_i2c_driver); |
e1d5b659 RR |
880 | |
881 | MODULE_AUTHOR("info@mocean-labs.com"); | |
882 | MODULE_DESCRIPTION("Xilinx I2C bus driver"); | |
883 | MODULE_LICENSE("GPL v2"); | |
a3664b51 | 884 | MODULE_ALIAS("platform:"DRIVER_NAME); |