2 * Copyright (c) 2003-2015 Broadcom Corporation
4 * This file is licensed under the terms of the GNU General Public
5 * License version 2. This program is licensed "as is" without any
6 * warranty of any kind, whether express or implied.
9 #include <linux/acpi.h>
10 #include <linux/clk.h>
11 #include <linux/completion.h>
12 #include <linux/i2c.h>
13 #include <linux/i2c-smbus.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/delay.h>
22 #define XLP9XX_I2C_DIV 0x0
23 #define XLP9XX_I2C_CTRL 0x1
24 #define XLP9XX_I2C_CMD 0x2
25 #define XLP9XX_I2C_STATUS 0x3
26 #define XLP9XX_I2C_MTXFIFO 0x4
27 #define XLP9XX_I2C_MRXFIFO 0x5
28 #define XLP9XX_I2C_MFIFOCTRL 0x6
29 #define XLP9XX_I2C_STXFIFO 0x7
30 #define XLP9XX_I2C_SRXFIFO 0x8
31 #define XLP9XX_I2C_SFIFOCTRL 0x9
32 #define XLP9XX_I2C_SLAVEADDR 0xA
33 #define XLP9XX_I2C_OWNADDR 0xB
34 #define XLP9XX_I2C_FIFOWCNT 0xC
35 #define XLP9XX_I2C_INTEN 0xD
36 #define XLP9XX_I2C_INTST 0xE
37 #define XLP9XX_I2C_WAITCNT 0xF
38 #define XLP9XX_I2C_TIMEOUT 0X10
39 #define XLP9XX_I2C_GENCALLADDR 0x11
41 #define XLP9XX_I2C_STATUS_BUSY BIT(0)
43 #define XLP9XX_I2C_CMD_START BIT(7)
44 #define XLP9XX_I2C_CMD_STOP BIT(6)
45 #define XLP9XX_I2C_CMD_READ BIT(5)
46 #define XLP9XX_I2C_CMD_WRITE BIT(4)
47 #define XLP9XX_I2C_CMD_ACK BIT(3)
49 #define XLP9XX_I2C_CTRL_MCTLEN_SHIFT 16
50 #define XLP9XX_I2C_CTRL_MCTLEN_MASK 0xffff0000
51 #define XLP9XX_I2C_CTRL_RST BIT(8)
52 #define XLP9XX_I2C_CTRL_EN BIT(6)
53 #define XLP9XX_I2C_CTRL_MASTER BIT(4)
54 #define XLP9XX_I2C_CTRL_FIFORD BIT(1)
55 #define XLP9XX_I2C_CTRL_ADDMODE BIT(0)
57 #define XLP9XX_I2C_INTEN_NACKADDR BIT(25)
58 #define XLP9XX_I2C_INTEN_SADDR BIT(13)
59 #define XLP9XX_I2C_INTEN_DATADONE BIT(12)
60 #define XLP9XX_I2C_INTEN_ARLOST BIT(11)
61 #define XLP9XX_I2C_INTEN_MFIFOFULL BIT(4)
62 #define XLP9XX_I2C_INTEN_MFIFOEMTY BIT(3)
63 #define XLP9XX_I2C_INTEN_MFIFOHI BIT(2)
64 #define XLP9XX_I2C_INTEN_BUSERR BIT(0)
66 #define XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT 8
67 #define XLP9XX_I2C_MFIFOCTRL_LOTH_SHIFT 0
68 #define XLP9XX_I2C_MFIFOCTRL_RST BIT(16)
70 #define XLP9XX_I2C_SLAVEADDR_RW BIT(0)
71 #define XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT 1
73 #define XLP9XX_I2C_IP_CLK_FREQ 133000000UL
74 #define XLP9XX_I2C_FIFO_SIZE 0x80U
75 #define XLP9XX_I2C_TIMEOUT_MS 1000
76 #define XLP9XX_I2C_BUSY_TIMEOUT 50
78 #define XLP9XX_I2C_FIFO_WCNT_MASK 0xff
79 #define XLP9XX_I2C_STATUS_ERRMASK (XLP9XX_I2C_INTEN_ARLOST | \
80 XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_BUSERR)
82 struct xlp9xx_i2c_dev
{
84 struct i2c_adapter adapter
;
85 struct completion msg_complete
;
86 struct i2c_smbus_alert_setup alert_data
;
87 struct i2c_client
*ara
;
93 u32 msg_buf_remaining
;
101 static inline void xlp9xx_write_i2c_reg(struct xlp9xx_i2c_dev
*priv
,
102 unsigned long reg
, u32 val
)
104 writel(val
, priv
->base
+ reg
);
107 static inline u32
xlp9xx_read_i2c_reg(struct xlp9xx_i2c_dev
*priv
,
110 return readl(priv
->base
+ reg
);
113 static void xlp9xx_i2c_mask_irq(struct xlp9xx_i2c_dev
*priv
, u32 mask
)
117 inten
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_INTEN
) & ~mask
;
118 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, inten
);
121 static void xlp9xx_i2c_unmask_irq(struct xlp9xx_i2c_dev
*priv
, u32 mask
)
125 inten
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_INTEN
) | mask
;
126 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, inten
);
129 static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev
*priv
)
134 /* interrupt after the first read to examine
135 * the length byte before proceeding further
138 else if (priv
->msg_buf_remaining
> XLP9XX_I2C_FIFO_SIZE
)
139 thres
= XLP9XX_I2C_FIFO_SIZE
;
141 thres
= priv
->msg_buf_remaining
;
143 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_MFIFOCTRL
,
144 thres
<< XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT
);
147 static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev
*priv
)
150 u8
*buf
= priv
->msg_buf
;
152 len
= min(priv
->msg_buf_remaining
, XLP9XX_I2C_FIFO_SIZE
);
153 for (i
= 0; i
< len
; i
++)
154 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_MTXFIFO
, buf
[i
]);
155 priv
->msg_buf_remaining
-= len
;
156 priv
->msg_buf
+= len
;
159 static void xlp9xx_i2c_update_rlen(struct xlp9xx_i2c_dev
*priv
)
164 * Update receive length. Re-read len to get the latest value,
165 * and then add 4 to have a minimum value that can be safely
166 * written. This is to account for the byte read above, the
167 * transfer in progress and any delays in the register I/O
169 val
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_CTRL
);
170 len
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_FIFOWCNT
) &
171 XLP9XX_I2C_FIFO_WCNT_MASK
;
172 len
= max_t(u32
, priv
->msg_len
, len
+ 4);
173 if (len
>= I2C_SMBUS_BLOCK_MAX
+ 2)
175 val
= (val
& ~XLP9XX_I2C_CTRL_MCTLEN_MASK
) |
176 (len
<< XLP9XX_I2C_CTRL_MCTLEN_SHIFT
);
177 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, val
);
180 static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev
*priv
)
183 u8 rlen
, *buf
= priv
->msg_buf
;
185 len
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_FIFOWCNT
) &
186 XLP9XX_I2C_FIFO_WCNT_MASK
;
189 if (priv
->len_recv
) {
190 /* read length byte */
191 rlen
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_MRXFIFO
);
194 * We expect at least 2 interrupts for I2C_M_RECV_LEN
195 * transactions. The length is updated during the first
196 * interrupt, and the buffer contents are only copied
197 * during subsequent interrupts. If in case the interrupts
198 * get merged we would complete the transaction without
199 * copying out the bytes from RX fifo. To avoid this now we
200 * drain the fifo as and when data is available.
201 * We drained the rlen byte already, decrement total length
206 if (rlen
> I2C_SMBUS_BLOCK_MAX
|| rlen
== 0) {
207 rlen
= 0; /*abort transfer */
208 priv
->msg_buf_remaining
= 0;
210 xlp9xx_i2c_update_rlen(priv
);
215 if (priv
->client_pec
)
216 ++rlen
; /* account for error check byte */
217 /* update remaining bytes and message length */
218 priv
->msg_buf_remaining
= rlen
;
219 priv
->msg_len
= rlen
+ 1;
220 xlp9xx_i2c_update_rlen(priv
);
221 priv
->len_recv
= false;
224 len
= min(priv
->msg_buf_remaining
, len
);
225 for (i
= 0; i
< len
; i
++, buf
++)
226 *buf
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_MRXFIFO
);
228 priv
->msg_buf_remaining
-= len
;
231 if (priv
->msg_buf_remaining
)
232 xlp9xx_i2c_update_rx_fifo_thres(priv
);
235 static irqreturn_t
xlp9xx_i2c_isr(int irq
, void *dev_id
)
237 struct xlp9xx_i2c_dev
*priv
= dev_id
;
240 status
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_INTST
);
244 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTST
, status
);
245 if (status
& XLP9XX_I2C_STATUS_ERRMASK
) {
246 priv
->msg_err
= status
;
250 /* SADDR ACK for SMBUS_QUICK */
251 if ((status
& XLP9XX_I2C_INTEN_SADDR
) && (priv
->msg_len
== 0))
254 if (!priv
->msg_read
) {
255 if (status
& XLP9XX_I2C_INTEN_MFIFOEMTY
) {
256 /* TX FIFO got empty, fill it up again */
257 if (priv
->msg_buf_remaining
)
258 xlp9xx_i2c_fill_tx_fifo(priv
);
260 xlp9xx_i2c_mask_irq(priv
,
261 XLP9XX_I2C_INTEN_MFIFOEMTY
);
264 if (status
& (XLP9XX_I2C_INTEN_DATADONE
|
265 XLP9XX_I2C_INTEN_MFIFOHI
)) {
266 /* data is in FIFO, read it */
267 if (priv
->msg_buf_remaining
)
268 xlp9xx_i2c_drain_rx_fifo(priv
);
272 /* Transfer complete */
273 if (status
& XLP9XX_I2C_INTEN_DATADONE
)
279 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
280 complete(&priv
->msg_complete
);
284 static int xlp9xx_i2c_check_bus_status(struct xlp9xx_i2c_dev
*priv
)
287 u32 busy_timeout
= XLP9XX_I2C_BUSY_TIMEOUT
;
289 while (busy_timeout
) {
290 status
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_STATUS
);
291 if ((status
& XLP9XX_I2C_STATUS_BUSY
) == 0)
295 usleep_range(1000, 1100);
304 static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev
*priv
)
309 * The controller uses 5 * SCL clock internally.
310 * So prescale value should be divided by 5.
312 prescale
= DIV_ROUND_UP(priv
->ip_clk_hz
, priv
->clk_hz
);
313 prescale
= ((prescale
- 8) / 5) - 1;
314 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, XLP9XX_I2C_CTRL_RST
);
315 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, XLP9XX_I2C_CTRL_EN
|
316 XLP9XX_I2C_CTRL_MASTER
);
317 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_DIV
, prescale
);
318 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
323 static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev
*priv
, struct i2c_msg
*msg
,
326 unsigned long timeleft
;
327 u32 intr_mask
, cmd
, val
, len
;
329 priv
->msg_buf
= msg
->buf
;
330 priv
->msg_buf_remaining
= priv
->msg_len
= msg
->len
;
332 priv
->msg_read
= (msg
->flags
& I2C_M_RD
);
333 reinit_completion(&priv
->msg_complete
);
336 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_MFIFOCTRL
,
337 XLP9XX_I2C_MFIFOCTRL_RST
);
340 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_SLAVEADDR
,
341 (msg
->addr
<< XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT
) |
342 (priv
->msg_read
? XLP9XX_I2C_SLAVEADDR_RW
: 0));
344 /* Build control word for transfer */
345 val
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_CTRL
);
347 val
&= ~XLP9XX_I2C_CTRL_FIFORD
;
349 val
|= XLP9XX_I2C_CTRL_FIFORD
; /* read */
351 if (msg
->flags
& I2C_M_TEN
)
352 val
|= XLP9XX_I2C_CTRL_ADDMODE
; /* 10-bit address mode*/
354 val
&= ~XLP9XX_I2C_CTRL_ADDMODE
;
356 priv
->len_recv
= msg
->flags
& I2C_M_RECV_LEN
;
357 len
= priv
->len_recv
? I2C_SMBUS_BLOCK_MAX
+ 2 : msg
->len
;
358 priv
->client_pec
= msg
->flags
& I2C_CLIENT_PEC
;
360 /* set FIFO threshold if reading */
362 xlp9xx_i2c_update_rx_fifo_thres(priv
);
364 /* set data length to be transferred */
365 val
= (val
& ~XLP9XX_I2C_CTRL_MCTLEN_MASK
) |
366 (len
<< XLP9XX_I2C_CTRL_MCTLEN_SHIFT
);
367 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, val
);
369 /* fill fifo during tx */
371 xlp9xx_i2c_fill_tx_fifo(priv
);
373 /* set interrupt mask */
374 intr_mask
= (XLP9XX_I2C_INTEN_ARLOST
| XLP9XX_I2C_INTEN_BUSERR
|
375 XLP9XX_I2C_INTEN_NACKADDR
| XLP9XX_I2C_INTEN_DATADONE
);
377 if (priv
->msg_read
) {
378 intr_mask
|= XLP9XX_I2C_INTEN_MFIFOHI
;
380 intr_mask
|= XLP9XX_I2C_INTEN_SADDR
;
383 intr_mask
|= XLP9XX_I2C_INTEN_SADDR
;
385 intr_mask
|= XLP9XX_I2C_INTEN_MFIFOEMTY
;
387 xlp9xx_i2c_unmask_irq(priv
, intr_mask
);
390 cmd
= XLP9XX_I2C_CMD_START
;
392 cmd
|= (priv
->msg_read
?
393 XLP9XX_I2C_CMD_READ
: XLP9XX_I2C_CMD_WRITE
);
395 cmd
|= XLP9XX_I2C_CMD_STOP
;
397 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CMD
, cmd
);
399 timeleft
= msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS
);
400 timeleft
= wait_for_completion_timeout(&priv
->msg_complete
, timeleft
);
402 if (priv
->msg_err
& XLP9XX_I2C_INTEN_BUSERR
) {
403 dev_dbg(priv
->dev
, "transfer error %x!\n", priv
->msg_err
);
404 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CMD
, XLP9XX_I2C_CMD_STOP
);
406 } else if (priv
->msg_err
& XLP9XX_I2C_INTEN_NACKADDR
) {
411 dev_dbg(priv
->dev
, "i2c transfer timed out!\n");
412 xlp9xx_i2c_init(priv
);
416 /* update msg->len with actual received length */
417 if (msg
->flags
& I2C_M_RECV_LEN
) {
420 msg
->len
= priv
->msg_len
;
425 static int xlp9xx_i2c_xfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
429 struct xlp9xx_i2c_dev
*priv
= i2c_get_adapdata(adap
);
431 ret
= xlp9xx_i2c_check_bus_status(priv
);
433 xlp9xx_i2c_init(priv
);
434 ret
= xlp9xx_i2c_check_bus_status(priv
);
439 for (i
= 0; i
< num
; i
++) {
440 ret
= xlp9xx_i2c_xfer_msg(priv
, &msgs
[i
], i
== num
- 1);
448 static u32
xlp9xx_i2c_functionality(struct i2c_adapter
*adapter
)
450 return I2C_FUNC_SMBUS_EMUL
| I2C_FUNC_SMBUS_READ_BLOCK_DATA
|
451 I2C_FUNC_I2C
| I2C_FUNC_10BIT_ADDR
;
454 static const struct i2c_algorithm xlp9xx_i2c_algo
= {
455 .master_xfer
= xlp9xx_i2c_xfer
,
456 .functionality
= xlp9xx_i2c_functionality
,
459 static int xlp9xx_i2c_get_frequency(struct platform_device
*pdev
,
460 struct xlp9xx_i2c_dev
*priv
)
466 clk
= devm_clk_get(&pdev
->dev
, NULL
);
468 priv
->ip_clk_hz
= XLP9XX_I2C_IP_CLK_FREQ
;
469 dev_dbg(&pdev
->dev
, "using default input frequency %u\n",
472 priv
->ip_clk_hz
= clk_get_rate(clk
);
475 err
= device_property_read_u32(&pdev
->dev
, "clock-frequency", &freq
);
477 freq
= I2C_MAX_STANDARD_MODE_FREQ
;
478 dev_dbg(&pdev
->dev
, "using default frequency %u\n", freq
);
479 } else if (freq
== 0 || freq
> I2C_MAX_FAST_MODE_FREQ
) {
480 dev_warn(&pdev
->dev
, "invalid frequency %u, using default\n",
482 freq
= I2C_MAX_STANDARD_MODE_FREQ
;
489 static int xlp9xx_i2c_smbus_setup(struct xlp9xx_i2c_dev
*priv
,
490 struct platform_device
*pdev
)
492 struct i2c_client
*ara
;
494 if (!priv
->alert_data
.irq
)
497 ara
= i2c_new_smbus_alert_device(&priv
->adapter
, &priv
->alert_data
);
506 static int xlp9xx_i2c_probe(struct platform_device
*pdev
)
508 struct xlp9xx_i2c_dev
*priv
;
511 priv
= devm_kzalloc(&pdev
->dev
, sizeof(*priv
), GFP_KERNEL
);
515 priv
->base
= devm_platform_ioremap_resource(pdev
, 0);
516 if (IS_ERR(priv
->base
))
517 return PTR_ERR(priv
->base
);
519 priv
->irq
= platform_get_irq(pdev
, 0);
523 priv
->alert_data
.irq
= platform_get_irq(pdev
, 1);
524 if (priv
->alert_data
.irq
<= 0)
525 priv
->alert_data
.irq
= 0;
527 xlp9xx_i2c_get_frequency(pdev
, priv
);
528 xlp9xx_i2c_init(priv
);
530 err
= devm_request_irq(&pdev
->dev
, priv
->irq
, xlp9xx_i2c_isr
, 0,
533 dev_err(&pdev
->dev
, "IRQ request failed!\n");
537 init_completion(&priv
->msg_complete
);
538 priv
->adapter
.dev
.parent
= &pdev
->dev
;
539 priv
->adapter
.algo
= &xlp9xx_i2c_algo
;
540 priv
->adapter
.class = I2C_CLASS_HWMON
;
541 ACPI_COMPANION_SET(&priv
->adapter
.dev
, ACPI_COMPANION(&pdev
->dev
));
542 priv
->adapter
.dev
.of_node
= pdev
->dev
.of_node
;
543 priv
->dev
= &pdev
->dev
;
545 snprintf(priv
->adapter
.name
, sizeof(priv
->adapter
.name
), "xlp9xx-i2c");
546 i2c_set_adapdata(&priv
->adapter
, priv
);
548 err
= i2c_add_adapter(&priv
->adapter
);
552 err
= xlp9xx_i2c_smbus_setup(priv
, pdev
);
554 dev_dbg(&pdev
->dev
, "No active SMBus alert %d\n", err
);
556 platform_set_drvdata(pdev
, priv
);
557 dev_dbg(&pdev
->dev
, "I2C bus:%d added\n", priv
->adapter
.nr
);
562 static int xlp9xx_i2c_remove(struct platform_device
*pdev
)
564 struct xlp9xx_i2c_dev
*priv
;
566 priv
= platform_get_drvdata(pdev
);
567 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
568 synchronize_irq(priv
->irq
);
569 i2c_del_adapter(&priv
->adapter
);
570 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, 0);
575 static const struct of_device_id xlp9xx_i2c_of_match
[] = {
576 { .compatible
= "netlogic,xlp980-i2c", },
579 MODULE_DEVICE_TABLE(of
, xlp9xx_i2c_of_match
);
582 static const struct acpi_device_id xlp9xx_i2c_acpi_ids
[] = {
587 MODULE_DEVICE_TABLE(acpi
, xlp9xx_i2c_acpi_ids
);
590 static struct platform_driver xlp9xx_i2c_driver
= {
591 .probe
= xlp9xx_i2c_probe
,
592 .remove
= xlp9xx_i2c_remove
,
594 .name
= "xlp9xx-i2c",
595 .of_match_table
= xlp9xx_i2c_of_match
,
596 .acpi_match_table
= ACPI_PTR(xlp9xx_i2c_acpi_ids
),
600 module_platform_driver(xlp9xx_i2c_driver
);
602 MODULE_AUTHOR("Subhendu Sekhar Behera <sbehera@broadcom.com>");
603 MODULE_DESCRIPTION("XLP9XX/5XX I2C Bus Controller Driver");
604 MODULE_LICENSE("GPL v2");