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_DEFAULT_FREQ 100000
75 #define XLP9XX_I2C_HIGH_FREQ 400000
76 #define XLP9XX_I2C_FIFO_SIZE 0x80U
77 #define XLP9XX_I2C_TIMEOUT_MS 1000
78 #define XLP9XX_I2C_BUSY_TIMEOUT 50
80 #define XLP9XX_I2C_FIFO_WCNT_MASK 0xff
81 #define XLP9XX_I2C_STATUS_ERRMASK (XLP9XX_I2C_INTEN_ARLOST | \
82 XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_BUSERR)
84 struct xlp9xx_i2c_dev
{
86 struct i2c_adapter adapter
;
87 struct completion msg_complete
;
88 struct i2c_smbus_alert_setup alert_data
;
89 struct i2c_client
*ara
;
95 u32 msg_buf_remaining
;
103 static inline void xlp9xx_write_i2c_reg(struct xlp9xx_i2c_dev
*priv
,
104 unsigned long reg
, u32 val
)
106 writel(val
, priv
->base
+ reg
);
109 static inline u32
xlp9xx_read_i2c_reg(struct xlp9xx_i2c_dev
*priv
,
112 return readl(priv
->base
+ reg
);
115 static void xlp9xx_i2c_mask_irq(struct xlp9xx_i2c_dev
*priv
, u32 mask
)
119 inten
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_INTEN
) & ~mask
;
120 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, inten
);
123 static void xlp9xx_i2c_unmask_irq(struct xlp9xx_i2c_dev
*priv
, u32 mask
)
127 inten
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_INTEN
) | mask
;
128 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, inten
);
131 static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev
*priv
)
136 /* interrupt after the first read to examine
137 * the length byte before proceeding further
140 else if (priv
->msg_buf_remaining
> XLP9XX_I2C_FIFO_SIZE
)
141 thres
= XLP9XX_I2C_FIFO_SIZE
;
143 thres
= priv
->msg_buf_remaining
;
145 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_MFIFOCTRL
,
146 thres
<< XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT
);
149 static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev
*priv
)
152 u8
*buf
= priv
->msg_buf
;
154 len
= min(priv
->msg_buf_remaining
, XLP9XX_I2C_FIFO_SIZE
);
155 for (i
= 0; i
< len
; i
++)
156 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_MTXFIFO
, buf
[i
]);
157 priv
->msg_buf_remaining
-= len
;
158 priv
->msg_buf
+= len
;
161 static void xlp9xx_i2c_update_rlen(struct xlp9xx_i2c_dev
*priv
)
166 * Update receive length. Re-read len to get the latest value,
167 * and then add 4 to have a minimum value that can be safely
168 * written. This is to account for the byte read above, the
169 * transfer in progress and any delays in the register I/O
171 val
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_CTRL
);
172 len
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_FIFOWCNT
) &
173 XLP9XX_I2C_FIFO_WCNT_MASK
;
174 len
= max_t(u32
, priv
->msg_len
, len
+ 4);
175 if (len
>= I2C_SMBUS_BLOCK_MAX
+ 2)
177 val
= (val
& ~XLP9XX_I2C_CTRL_MCTLEN_MASK
) |
178 (len
<< XLP9XX_I2C_CTRL_MCTLEN_SHIFT
);
179 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, val
);
182 static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev
*priv
)
185 u8 rlen
, *buf
= priv
->msg_buf
;
187 len
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_FIFOWCNT
) &
188 XLP9XX_I2C_FIFO_WCNT_MASK
;
191 if (priv
->len_recv
) {
192 /* read length byte */
193 rlen
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_MRXFIFO
);
194 if (rlen
> I2C_SMBUS_BLOCK_MAX
|| rlen
== 0) {
195 rlen
= 0; /*abort transfer */
196 priv
->msg_buf_remaining
= 0;
200 if (priv
->client_pec
)
201 ++rlen
; /* account for error check byte */
202 /* update remaining bytes and message length */
203 priv
->msg_buf_remaining
= rlen
;
204 priv
->msg_len
= rlen
+ 1;
206 xlp9xx_i2c_update_rlen(priv
);
207 priv
->len_recv
= false;
209 len
= min(priv
->msg_buf_remaining
, len
);
210 for (i
= 0; i
< len
; i
++, buf
++)
211 *buf
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_MRXFIFO
);
213 priv
->msg_buf_remaining
-= len
;
218 if (priv
->msg_buf_remaining
)
219 xlp9xx_i2c_update_rx_fifo_thres(priv
);
222 static irqreturn_t
xlp9xx_i2c_isr(int irq
, void *dev_id
)
224 struct xlp9xx_i2c_dev
*priv
= dev_id
;
227 status
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_INTST
);
231 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTST
, status
);
232 if (status
& XLP9XX_I2C_STATUS_ERRMASK
) {
233 priv
->msg_err
= status
;
237 /* SADDR ACK for SMBUS_QUICK */
238 if ((status
& XLP9XX_I2C_INTEN_SADDR
) && (priv
->msg_len
== 0))
241 if (!priv
->msg_read
) {
242 if (status
& XLP9XX_I2C_INTEN_MFIFOEMTY
) {
243 /* TX FIFO got empty, fill it up again */
244 if (priv
->msg_buf_remaining
)
245 xlp9xx_i2c_fill_tx_fifo(priv
);
247 xlp9xx_i2c_mask_irq(priv
,
248 XLP9XX_I2C_INTEN_MFIFOEMTY
);
251 if (status
& (XLP9XX_I2C_INTEN_DATADONE
|
252 XLP9XX_I2C_INTEN_MFIFOHI
)) {
253 /* data is in FIFO, read it */
254 if (priv
->msg_buf_remaining
)
255 xlp9xx_i2c_drain_rx_fifo(priv
);
259 /* Transfer complete */
260 if (status
& XLP9XX_I2C_INTEN_DATADONE
)
266 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
267 complete(&priv
->msg_complete
);
271 static int xlp9xx_i2c_check_bus_status(struct xlp9xx_i2c_dev
*priv
)
274 u32 busy_timeout
= XLP9XX_I2C_BUSY_TIMEOUT
;
276 while (busy_timeout
) {
277 status
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_STATUS
);
278 if ((status
& XLP9XX_I2C_STATUS_BUSY
) == 0)
282 usleep_range(1000, 1100);
291 static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev
*priv
)
296 * The controller uses 5 * SCL clock internally.
297 * So prescale value should be divided by 5.
299 prescale
= DIV_ROUND_UP(priv
->ip_clk_hz
, priv
->clk_hz
);
300 prescale
= ((prescale
- 8) / 5) - 1;
301 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, XLP9XX_I2C_CTRL_RST
);
302 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, XLP9XX_I2C_CTRL_EN
|
303 XLP9XX_I2C_CTRL_MASTER
);
304 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_DIV
, prescale
);
305 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
310 static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev
*priv
, struct i2c_msg
*msg
,
313 unsigned long timeleft
;
314 u32 intr_mask
, cmd
, val
, len
;
316 priv
->msg_buf
= msg
->buf
;
317 priv
->msg_buf_remaining
= priv
->msg_len
= msg
->len
;
319 priv
->msg_read
= (msg
->flags
& I2C_M_RD
);
320 reinit_completion(&priv
->msg_complete
);
323 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_MFIFOCTRL
,
324 XLP9XX_I2C_MFIFOCTRL_RST
);
327 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_SLAVEADDR
,
328 (msg
->addr
<< XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT
) |
329 (priv
->msg_read
? XLP9XX_I2C_SLAVEADDR_RW
: 0));
331 /* Build control word for transfer */
332 val
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_CTRL
);
334 val
&= ~XLP9XX_I2C_CTRL_FIFORD
;
336 val
|= XLP9XX_I2C_CTRL_FIFORD
; /* read */
338 if (msg
->flags
& I2C_M_TEN
)
339 val
|= XLP9XX_I2C_CTRL_ADDMODE
; /* 10-bit address mode*/
341 val
&= ~XLP9XX_I2C_CTRL_ADDMODE
;
343 priv
->len_recv
= msg
->flags
& I2C_M_RECV_LEN
;
344 len
= priv
->len_recv
? I2C_SMBUS_BLOCK_MAX
+ 2 : msg
->len
;
345 priv
->client_pec
= msg
->flags
& I2C_CLIENT_PEC
;
347 /* set FIFO threshold if reading */
349 xlp9xx_i2c_update_rx_fifo_thres(priv
);
351 /* set data length to be transferred */
352 val
= (val
& ~XLP9XX_I2C_CTRL_MCTLEN_MASK
) |
353 (len
<< XLP9XX_I2C_CTRL_MCTLEN_SHIFT
);
354 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, val
);
356 /* fill fifo during tx */
358 xlp9xx_i2c_fill_tx_fifo(priv
);
360 /* set interrupt mask */
361 intr_mask
= (XLP9XX_I2C_INTEN_ARLOST
| XLP9XX_I2C_INTEN_BUSERR
|
362 XLP9XX_I2C_INTEN_NACKADDR
| XLP9XX_I2C_INTEN_DATADONE
);
364 if (priv
->msg_read
) {
365 intr_mask
|= XLP9XX_I2C_INTEN_MFIFOHI
;
367 intr_mask
|= XLP9XX_I2C_INTEN_SADDR
;
370 intr_mask
|= XLP9XX_I2C_INTEN_SADDR
;
372 intr_mask
|= XLP9XX_I2C_INTEN_MFIFOEMTY
;
374 xlp9xx_i2c_unmask_irq(priv
, intr_mask
);
377 cmd
= XLP9XX_I2C_CMD_START
;
379 cmd
|= (priv
->msg_read
?
380 XLP9XX_I2C_CMD_READ
: XLP9XX_I2C_CMD_WRITE
);
382 cmd
|= XLP9XX_I2C_CMD_STOP
;
384 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CMD
, cmd
);
386 timeleft
= msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS
);
387 timeleft
= wait_for_completion_timeout(&priv
->msg_complete
, timeleft
);
389 if (priv
->msg_err
& XLP9XX_I2C_INTEN_BUSERR
) {
390 dev_dbg(priv
->dev
, "transfer error %x!\n", priv
->msg_err
);
391 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CMD
, XLP9XX_I2C_CMD_STOP
);
393 } else if (priv
->msg_err
& XLP9XX_I2C_INTEN_NACKADDR
) {
398 dev_dbg(priv
->dev
, "i2c transfer timed out!\n");
399 xlp9xx_i2c_init(priv
);
403 /* update msg->len with actual received length */
404 if (msg
->flags
& I2C_M_RECV_LEN
) {
407 msg
->len
= priv
->msg_len
;
412 static int xlp9xx_i2c_xfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
416 struct xlp9xx_i2c_dev
*priv
= i2c_get_adapdata(adap
);
418 ret
= xlp9xx_i2c_check_bus_status(priv
);
420 xlp9xx_i2c_init(priv
);
421 ret
= xlp9xx_i2c_check_bus_status(priv
);
426 for (i
= 0; i
< num
; i
++) {
427 ret
= xlp9xx_i2c_xfer_msg(priv
, &msgs
[i
], i
== num
- 1);
435 static u32
xlp9xx_i2c_functionality(struct i2c_adapter
*adapter
)
437 return I2C_FUNC_SMBUS_EMUL
| I2C_FUNC_SMBUS_READ_BLOCK_DATA
|
438 I2C_FUNC_I2C
| I2C_FUNC_10BIT_ADDR
;
441 static const struct i2c_algorithm xlp9xx_i2c_algo
= {
442 .master_xfer
= xlp9xx_i2c_xfer
,
443 .functionality
= xlp9xx_i2c_functionality
,
446 static int xlp9xx_i2c_get_frequency(struct platform_device
*pdev
,
447 struct xlp9xx_i2c_dev
*priv
)
453 clk
= devm_clk_get(&pdev
->dev
, NULL
);
455 priv
->ip_clk_hz
= XLP9XX_I2C_IP_CLK_FREQ
;
456 dev_dbg(&pdev
->dev
, "using default input frequency %u\n",
459 priv
->ip_clk_hz
= clk_get_rate(clk
);
462 err
= device_property_read_u32(&pdev
->dev
, "clock-frequency", &freq
);
464 freq
= XLP9XX_I2C_DEFAULT_FREQ
;
465 dev_dbg(&pdev
->dev
, "using default frequency %u\n", freq
);
466 } else if (freq
== 0 || freq
> XLP9XX_I2C_HIGH_FREQ
) {
467 dev_warn(&pdev
->dev
, "invalid frequency %u, using default\n",
469 freq
= XLP9XX_I2C_DEFAULT_FREQ
;
476 static int xlp9xx_i2c_smbus_setup(struct xlp9xx_i2c_dev
*priv
,
477 struct platform_device
*pdev
)
479 if (!priv
->alert_data
.irq
)
482 priv
->ara
= i2c_setup_smbus_alert(&priv
->adapter
, &priv
->alert_data
);
489 static int xlp9xx_i2c_probe(struct platform_device
*pdev
)
491 struct xlp9xx_i2c_dev
*priv
;
492 struct resource
*res
;
495 priv
= devm_kzalloc(&pdev
->dev
, sizeof(*priv
), GFP_KERNEL
);
499 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
500 priv
->base
= devm_ioremap_resource(&pdev
->dev
, res
);
501 if (IS_ERR(priv
->base
))
502 return PTR_ERR(priv
->base
);
504 priv
->irq
= platform_get_irq(pdev
, 0);
505 if (priv
->irq
<= 0) {
506 dev_err(&pdev
->dev
, "invalid irq!\n");
510 priv
->alert_data
.irq
= platform_get_irq(pdev
, 1);
511 if (priv
->alert_data
.irq
<= 0)
512 priv
->alert_data
.irq
= 0;
514 xlp9xx_i2c_get_frequency(pdev
, priv
);
515 xlp9xx_i2c_init(priv
);
517 err
= devm_request_irq(&pdev
->dev
, priv
->irq
, xlp9xx_i2c_isr
, 0,
520 dev_err(&pdev
->dev
, "IRQ request failed!\n");
524 init_completion(&priv
->msg_complete
);
525 priv
->adapter
.dev
.parent
= &pdev
->dev
;
526 priv
->adapter
.algo
= &xlp9xx_i2c_algo
;
527 priv
->adapter
.class = I2C_CLASS_HWMON
;
528 ACPI_COMPANION_SET(&priv
->adapter
.dev
, ACPI_COMPANION(&pdev
->dev
));
529 priv
->adapter
.dev
.of_node
= pdev
->dev
.of_node
;
530 priv
->dev
= &pdev
->dev
;
532 snprintf(priv
->adapter
.name
, sizeof(priv
->adapter
.name
), "xlp9xx-i2c");
533 i2c_set_adapdata(&priv
->adapter
, priv
);
535 err
= i2c_add_adapter(&priv
->adapter
);
539 err
= xlp9xx_i2c_smbus_setup(priv
, pdev
);
541 dev_dbg(&pdev
->dev
, "No active SMBus alert %d\n", err
);
543 platform_set_drvdata(pdev
, priv
);
544 dev_dbg(&pdev
->dev
, "I2C bus:%d added\n", priv
->adapter
.nr
);
549 static int xlp9xx_i2c_remove(struct platform_device
*pdev
)
551 struct xlp9xx_i2c_dev
*priv
;
553 priv
= platform_get_drvdata(pdev
);
554 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
555 synchronize_irq(priv
->irq
);
556 i2c_del_adapter(&priv
->adapter
);
557 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, 0);
562 static const struct of_device_id xlp9xx_i2c_of_match
[] = {
563 { .compatible
= "netlogic,xlp980-i2c", },
566 MODULE_DEVICE_TABLE(of
, xlp9xx_i2c_of_match
);
569 static const struct acpi_device_id xlp9xx_i2c_acpi_ids
[] = {
574 MODULE_DEVICE_TABLE(acpi
, xlp9xx_i2c_acpi_ids
);
577 static struct platform_driver xlp9xx_i2c_driver
= {
578 .probe
= xlp9xx_i2c_probe
,
579 .remove
= xlp9xx_i2c_remove
,
581 .name
= "xlp9xx-i2c",
582 .of_match_table
= xlp9xx_i2c_of_match
,
583 .acpi_match_table
= ACPI_PTR(xlp9xx_i2c_acpi_ids
),
587 module_platform_driver(xlp9xx_i2c_driver
);
589 MODULE_AUTHOR("Subhendu Sekhar Behera <sbehera@broadcom.com>");
590 MODULE_DESCRIPTION("XLP9XX/5XX I2C Bus Controller Driver");
591 MODULE_LICENSE("GPL v2");