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
);
196 * We expect at least 2 interrupts for I2C_M_RECV_LEN
197 * transactions. The length is updated during the first
198 * interrupt, and the buffer contents are only copied
199 * during subsequent interrupts. If in case the interrupts
200 * get merged we would complete the transaction without
201 * copying out the bytes from RX fifo. To avoid this now we
202 * drain the fifo as and when data is available.
203 * We drained the rlen byte already, decrement total length
208 if (rlen
> I2C_SMBUS_BLOCK_MAX
|| rlen
== 0) {
209 rlen
= 0; /*abort transfer */
210 priv
->msg_buf_remaining
= 0;
212 xlp9xx_i2c_update_rlen(priv
);
217 if (priv
->client_pec
)
218 ++rlen
; /* account for error check byte */
219 /* update remaining bytes and message length */
220 priv
->msg_buf_remaining
= rlen
;
221 priv
->msg_len
= rlen
+ 1;
222 xlp9xx_i2c_update_rlen(priv
);
223 priv
->len_recv
= false;
226 len
= min(priv
->msg_buf_remaining
, len
);
227 for (i
= 0; i
< len
; i
++, buf
++)
228 *buf
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_MRXFIFO
);
230 priv
->msg_buf_remaining
-= len
;
233 if (priv
->msg_buf_remaining
)
234 xlp9xx_i2c_update_rx_fifo_thres(priv
);
237 static irqreturn_t
xlp9xx_i2c_isr(int irq
, void *dev_id
)
239 struct xlp9xx_i2c_dev
*priv
= dev_id
;
242 status
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_INTST
);
246 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTST
, status
);
247 if (status
& XLP9XX_I2C_STATUS_ERRMASK
) {
248 priv
->msg_err
= status
;
252 /* SADDR ACK for SMBUS_QUICK */
253 if ((status
& XLP9XX_I2C_INTEN_SADDR
) && (priv
->msg_len
== 0))
256 if (!priv
->msg_read
) {
257 if (status
& XLP9XX_I2C_INTEN_MFIFOEMTY
) {
258 /* TX FIFO got empty, fill it up again */
259 if (priv
->msg_buf_remaining
)
260 xlp9xx_i2c_fill_tx_fifo(priv
);
262 xlp9xx_i2c_mask_irq(priv
,
263 XLP9XX_I2C_INTEN_MFIFOEMTY
);
266 if (status
& (XLP9XX_I2C_INTEN_DATADONE
|
267 XLP9XX_I2C_INTEN_MFIFOHI
)) {
268 /* data is in FIFO, read it */
269 if (priv
->msg_buf_remaining
)
270 xlp9xx_i2c_drain_rx_fifo(priv
);
274 /* Transfer complete */
275 if (status
& XLP9XX_I2C_INTEN_DATADONE
)
281 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
282 complete(&priv
->msg_complete
);
286 static int xlp9xx_i2c_check_bus_status(struct xlp9xx_i2c_dev
*priv
)
289 u32 busy_timeout
= XLP9XX_I2C_BUSY_TIMEOUT
;
291 while (busy_timeout
) {
292 status
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_STATUS
);
293 if ((status
& XLP9XX_I2C_STATUS_BUSY
) == 0)
297 usleep_range(1000, 1100);
306 static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev
*priv
)
311 * The controller uses 5 * SCL clock internally.
312 * So prescale value should be divided by 5.
314 prescale
= DIV_ROUND_UP(priv
->ip_clk_hz
, priv
->clk_hz
);
315 prescale
= ((prescale
- 8) / 5) - 1;
316 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, XLP9XX_I2C_CTRL_RST
);
317 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, XLP9XX_I2C_CTRL_EN
|
318 XLP9XX_I2C_CTRL_MASTER
);
319 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_DIV
, prescale
);
320 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
325 static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev
*priv
, struct i2c_msg
*msg
,
328 unsigned long timeleft
;
329 u32 intr_mask
, cmd
, val
, len
;
331 priv
->msg_buf
= msg
->buf
;
332 priv
->msg_buf_remaining
= priv
->msg_len
= msg
->len
;
334 priv
->msg_read
= (msg
->flags
& I2C_M_RD
);
335 reinit_completion(&priv
->msg_complete
);
338 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_MFIFOCTRL
,
339 XLP9XX_I2C_MFIFOCTRL_RST
);
342 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_SLAVEADDR
,
343 (msg
->addr
<< XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT
) |
344 (priv
->msg_read
? XLP9XX_I2C_SLAVEADDR_RW
: 0));
346 /* Build control word for transfer */
347 val
= xlp9xx_read_i2c_reg(priv
, XLP9XX_I2C_CTRL
);
349 val
&= ~XLP9XX_I2C_CTRL_FIFORD
;
351 val
|= XLP9XX_I2C_CTRL_FIFORD
; /* read */
353 if (msg
->flags
& I2C_M_TEN
)
354 val
|= XLP9XX_I2C_CTRL_ADDMODE
; /* 10-bit address mode*/
356 val
&= ~XLP9XX_I2C_CTRL_ADDMODE
;
358 priv
->len_recv
= msg
->flags
& I2C_M_RECV_LEN
;
359 len
= priv
->len_recv
? I2C_SMBUS_BLOCK_MAX
+ 2 : msg
->len
;
360 priv
->client_pec
= msg
->flags
& I2C_CLIENT_PEC
;
362 /* set FIFO threshold if reading */
364 xlp9xx_i2c_update_rx_fifo_thres(priv
);
366 /* set data length to be transferred */
367 val
= (val
& ~XLP9XX_I2C_CTRL_MCTLEN_MASK
) |
368 (len
<< XLP9XX_I2C_CTRL_MCTLEN_SHIFT
);
369 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, val
);
371 /* fill fifo during tx */
373 xlp9xx_i2c_fill_tx_fifo(priv
);
375 /* set interrupt mask */
376 intr_mask
= (XLP9XX_I2C_INTEN_ARLOST
| XLP9XX_I2C_INTEN_BUSERR
|
377 XLP9XX_I2C_INTEN_NACKADDR
| XLP9XX_I2C_INTEN_DATADONE
);
379 if (priv
->msg_read
) {
380 intr_mask
|= XLP9XX_I2C_INTEN_MFIFOHI
;
382 intr_mask
|= XLP9XX_I2C_INTEN_SADDR
;
385 intr_mask
|= XLP9XX_I2C_INTEN_SADDR
;
387 intr_mask
|= XLP9XX_I2C_INTEN_MFIFOEMTY
;
389 xlp9xx_i2c_unmask_irq(priv
, intr_mask
);
392 cmd
= XLP9XX_I2C_CMD_START
;
394 cmd
|= (priv
->msg_read
?
395 XLP9XX_I2C_CMD_READ
: XLP9XX_I2C_CMD_WRITE
);
397 cmd
|= XLP9XX_I2C_CMD_STOP
;
399 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CMD
, cmd
);
401 timeleft
= msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS
);
402 timeleft
= wait_for_completion_timeout(&priv
->msg_complete
, timeleft
);
404 if (priv
->msg_err
& XLP9XX_I2C_INTEN_BUSERR
) {
405 dev_dbg(priv
->dev
, "transfer error %x!\n", priv
->msg_err
);
406 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CMD
, XLP9XX_I2C_CMD_STOP
);
408 } else if (priv
->msg_err
& XLP9XX_I2C_INTEN_NACKADDR
) {
413 dev_dbg(priv
->dev
, "i2c transfer timed out!\n");
414 xlp9xx_i2c_init(priv
);
418 /* update msg->len with actual received length */
419 if (msg
->flags
& I2C_M_RECV_LEN
) {
422 msg
->len
= priv
->msg_len
;
427 static int xlp9xx_i2c_xfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
431 struct xlp9xx_i2c_dev
*priv
= i2c_get_adapdata(adap
);
433 ret
= xlp9xx_i2c_check_bus_status(priv
);
435 xlp9xx_i2c_init(priv
);
436 ret
= xlp9xx_i2c_check_bus_status(priv
);
441 for (i
= 0; i
< num
; i
++) {
442 ret
= xlp9xx_i2c_xfer_msg(priv
, &msgs
[i
], i
== num
- 1);
450 static u32
xlp9xx_i2c_functionality(struct i2c_adapter
*adapter
)
452 return I2C_FUNC_SMBUS_EMUL
| I2C_FUNC_SMBUS_READ_BLOCK_DATA
|
453 I2C_FUNC_I2C
| I2C_FUNC_10BIT_ADDR
;
456 static const struct i2c_algorithm xlp9xx_i2c_algo
= {
457 .master_xfer
= xlp9xx_i2c_xfer
,
458 .functionality
= xlp9xx_i2c_functionality
,
461 static int xlp9xx_i2c_get_frequency(struct platform_device
*pdev
,
462 struct xlp9xx_i2c_dev
*priv
)
468 clk
= devm_clk_get(&pdev
->dev
, NULL
);
470 priv
->ip_clk_hz
= XLP9XX_I2C_IP_CLK_FREQ
;
471 dev_dbg(&pdev
->dev
, "using default input frequency %u\n",
474 priv
->ip_clk_hz
= clk_get_rate(clk
);
477 err
= device_property_read_u32(&pdev
->dev
, "clock-frequency", &freq
);
479 freq
= XLP9XX_I2C_DEFAULT_FREQ
;
480 dev_dbg(&pdev
->dev
, "using default frequency %u\n", freq
);
481 } else if (freq
== 0 || freq
> XLP9XX_I2C_HIGH_FREQ
) {
482 dev_warn(&pdev
->dev
, "invalid frequency %u, using default\n",
484 freq
= XLP9XX_I2C_DEFAULT_FREQ
;
491 static int xlp9xx_i2c_smbus_setup(struct xlp9xx_i2c_dev
*priv
,
492 struct platform_device
*pdev
)
494 if (!priv
->alert_data
.irq
)
497 priv
->ara
= i2c_setup_smbus_alert(&priv
->adapter
, &priv
->alert_data
);
504 static int xlp9xx_i2c_probe(struct platform_device
*pdev
)
506 struct xlp9xx_i2c_dev
*priv
;
507 struct resource
*res
;
510 priv
= devm_kzalloc(&pdev
->dev
, sizeof(*priv
), GFP_KERNEL
);
514 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
515 priv
->base
= devm_ioremap_resource(&pdev
->dev
, res
);
516 if (IS_ERR(priv
->base
))
517 return PTR_ERR(priv
->base
);
519 priv
->irq
= platform_get_irq(pdev
, 0);
520 if (priv
->irq
<= 0) {
521 dev_err(&pdev
->dev
, "invalid irq!\n");
525 priv
->alert_data
.irq
= platform_get_irq(pdev
, 1);
526 if (priv
->alert_data
.irq
<= 0)
527 priv
->alert_data
.irq
= 0;
529 xlp9xx_i2c_get_frequency(pdev
, priv
);
530 xlp9xx_i2c_init(priv
);
532 err
= devm_request_irq(&pdev
->dev
, priv
->irq
, xlp9xx_i2c_isr
, 0,
535 dev_err(&pdev
->dev
, "IRQ request failed!\n");
539 init_completion(&priv
->msg_complete
);
540 priv
->adapter
.dev
.parent
= &pdev
->dev
;
541 priv
->adapter
.algo
= &xlp9xx_i2c_algo
;
542 priv
->adapter
.class = I2C_CLASS_HWMON
;
543 ACPI_COMPANION_SET(&priv
->adapter
.dev
, ACPI_COMPANION(&pdev
->dev
));
544 priv
->adapter
.dev
.of_node
= pdev
->dev
.of_node
;
545 priv
->dev
= &pdev
->dev
;
547 snprintf(priv
->adapter
.name
, sizeof(priv
->adapter
.name
), "xlp9xx-i2c");
548 i2c_set_adapdata(&priv
->adapter
, priv
);
550 err
= i2c_add_adapter(&priv
->adapter
);
554 err
= xlp9xx_i2c_smbus_setup(priv
, pdev
);
556 dev_dbg(&pdev
->dev
, "No active SMBus alert %d\n", err
);
558 platform_set_drvdata(pdev
, priv
);
559 dev_dbg(&pdev
->dev
, "I2C bus:%d added\n", priv
->adapter
.nr
);
564 static int xlp9xx_i2c_remove(struct platform_device
*pdev
)
566 struct xlp9xx_i2c_dev
*priv
;
568 priv
= platform_get_drvdata(pdev
);
569 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_INTEN
, 0);
570 synchronize_irq(priv
->irq
);
571 i2c_del_adapter(&priv
->adapter
);
572 xlp9xx_write_i2c_reg(priv
, XLP9XX_I2C_CTRL
, 0);
577 static const struct of_device_id xlp9xx_i2c_of_match
[] = {
578 { .compatible
= "netlogic,xlp980-i2c", },
581 MODULE_DEVICE_TABLE(of
, xlp9xx_i2c_of_match
);
584 static const struct acpi_device_id xlp9xx_i2c_acpi_ids
[] = {
589 MODULE_DEVICE_TABLE(acpi
, xlp9xx_i2c_acpi_ids
);
592 static struct platform_driver xlp9xx_i2c_driver
= {
593 .probe
= xlp9xx_i2c_probe
,
594 .remove
= xlp9xx_i2c_remove
,
596 .name
= "xlp9xx-i2c",
597 .of_match_table
= xlp9xx_i2c_of_match
,
598 .acpi_match_table
= ACPI_PTR(xlp9xx_i2c_acpi_ids
),
602 module_platform_driver(xlp9xx_i2c_driver
);
604 MODULE_AUTHOR("Subhendu Sekhar Behera <sbehera@broadcom.com>");
605 MODULE_DESCRIPTION("XLP9XX/5XX I2C Bus Controller Driver");
606 MODULE_LICENSE("GPL v2");