1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * X-Gene SLIMpro I2C Driver
5 * Copyright (c) 2014, Applied Micro Circuits Corporation
9 * This driver provides support for X-Gene SLIMpro I2C device access
10 * using the APM X-Gene SLIMpro mailbox driver.
13 #include <linux/acpi.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/i2c.h>
16 #include <linux/interrupt.h>
18 #include <linux/mailbox_client.h>
19 #include <linux/module.h>
21 #include <linux/platform_device.h>
23 #define MAILBOX_OP_TIMEOUT 1000 /* Operation time out in ms */
24 #define MAILBOX_I2C_INDEX 0
25 #define SLIMPRO_IIC_BUS 1 /* Use I2C bus 1 only */
27 #define SMBUS_CMD_LEN 1
32 #define SLIMPRO_IIC_I2C_PROTOCOL 0
33 #define SLIMPRO_IIC_SMB_PROTOCOL 1
35 #define SLIMPRO_IIC_READ 0
36 #define SLIMPRO_IIC_WRITE 1
38 #define IIC_SMB_WITHOUT_DATA_LEN 0
39 #define IIC_SMB_WITH_DATA_LEN 1
41 #define SLIMPRO_DEBUG_MSG 0
42 #define SLIMPRO_MSG_TYPE_SHIFT 28
43 #define SLIMPRO_DBG_SUBTYPE_I2C1READ 4
44 #define SLIMPRO_DBGMSG_TYPE_SHIFT 24
45 #define SLIMPRO_DBGMSG_TYPE_MASK 0x0F000000U
46 #define SLIMPRO_IIC_DEV_SHIFT 23
47 #define SLIMPRO_IIC_DEV_MASK 0x00800000U
48 #define SLIMPRO_IIC_DEVID_SHIFT 13
49 #define SLIMPRO_IIC_DEVID_MASK 0x007FE000U
50 #define SLIMPRO_IIC_RW_SHIFT 12
51 #define SLIMPRO_IIC_RW_MASK 0x00001000U
52 #define SLIMPRO_IIC_PROTO_SHIFT 11
53 #define SLIMPRO_IIC_PROTO_MASK 0x00000800U
54 #define SLIMPRO_IIC_ADDRLEN_SHIFT 8
55 #define SLIMPRO_IIC_ADDRLEN_MASK 0x00000700U
56 #define SLIMPRO_IIC_DATALEN_SHIFT 0
57 #define SLIMPRO_IIC_DATALEN_MASK 0x000000FFU
60 * SLIMpro I2C message encode
62 * dev - Controller number (0-based)
63 * chip - I2C chip address
64 * op - SLIMPRO_IIC_READ or SLIMPRO_IIC_WRITE
65 * proto - SLIMPRO_IIC_SMB_PROTOCOL or SLIMPRO_IIC_I2C_PROTOCOL
66 * addrlen - Length of the address field
67 * datalen - Length of the data field
69 #define SLIMPRO_IIC_ENCODE_MSG(dev, chip, op, proto, addrlen, datalen) \
70 ((SLIMPRO_DEBUG_MSG << SLIMPRO_MSG_TYPE_SHIFT) | \
71 ((SLIMPRO_DBG_SUBTYPE_I2C1READ << SLIMPRO_DBGMSG_TYPE_SHIFT) & \
72 SLIMPRO_DBGMSG_TYPE_MASK) | \
73 ((dev << SLIMPRO_IIC_DEV_SHIFT) & SLIMPRO_IIC_DEV_MASK) | \
74 ((chip << SLIMPRO_IIC_DEVID_SHIFT) & SLIMPRO_IIC_DEVID_MASK) | \
75 ((op << SLIMPRO_IIC_RW_SHIFT) & SLIMPRO_IIC_RW_MASK) | \
76 ((proto << SLIMPRO_IIC_PROTO_SHIFT) & SLIMPRO_IIC_PROTO_MASK) | \
77 ((addrlen << SLIMPRO_IIC_ADDRLEN_SHIFT) & SLIMPRO_IIC_ADDRLEN_MASK) | \
78 ((datalen << SLIMPRO_IIC_DATALEN_SHIFT) & SLIMPRO_IIC_DATALEN_MASK))
80 #define SLIMPRO_MSG_TYPE(v) (((v) & 0xF0000000) >> 28)
83 * Encode for upper address for block data
85 #define SLIMPRO_IIC_ENCODE_FLAG_BUFADDR 0x80000000
86 #define SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(a) ((u32) (((a) << 30) \
88 #define SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(a) ((u32) (((a) >> 12) \
90 #define SLIMPRO_IIC_ENCODE_ADDR(a) ((a) & 0x000FFFFF)
92 #define SLIMPRO_IIC_MSG_DWORD_COUNT 3
94 struct slimpro_i2c_dev {
95 struct i2c_adapter adapter;
97 struct mbox_chan *mbox_chan;
98 struct pcc_mbox_chan *pcc_chan;
99 struct mbox_client mbox_client;
101 struct completion rd_complete;
102 u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* dma_buffer[0] is used for length */
104 phys_addr_t comm_base_addr;
108 #define to_slimpro_i2c_dev(cl) \
109 container_of(cl, struct slimpro_i2c_dev, mbox_client)
111 enum slimpro_i2c_version {
112 XGENE_SLIMPRO_I2C_V1 = 0,
113 XGENE_SLIMPRO_I2C_V2 = 1,
117 * This function tests and clears a bitmask then returns its old value
119 static u16 xgene_word_tst_and_clr(u16 *addr, u16 mask)
123 val = le16_to_cpu(READ_ONCE(*addr));
126 WRITE_ONCE(*addr, cpu_to_le16(val));
131 static void slimpro_i2c_rx_cb(struct mbox_client *cl, void *mssg)
133 struct slimpro_i2c_dev *ctx = to_slimpro_i2c_dev(cl);
136 * Response message format:
137 * mssg[0] is the return code of the operation
138 * mssg[1] is the first data word
139 * mssg[2] is NOT used
142 *ctx->resp_msg = ((u32 *)mssg)[1];
144 if (ctx->mbox_client.tx_block)
145 complete(&ctx->rd_complete);
148 static void slimpro_i2c_pcc_rx_cb(struct mbox_client *cl, void *msg)
150 struct slimpro_i2c_dev *ctx = to_slimpro_i2c_dev(cl);
151 struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
153 /* Check if platform sends interrupt */
154 if (!xgene_word_tst_and_clr(&generic_comm_base->status,
155 PCC_STATUS_SCI_DOORBELL))
158 if (xgene_word_tst_and_clr(&generic_comm_base->status,
159 PCC_STATUS_CMD_COMPLETE)) {
160 msg = generic_comm_base + 1;
162 /* Response message msg[1] contains the return value. */
164 *ctx->resp_msg = ((u32 *)msg)[1];
166 complete(&ctx->rd_complete);
170 static void slimpro_i2c_pcc_tx_prepare(struct slimpro_i2c_dev *ctx, u32 *msg)
172 struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
173 u32 *ptr = (void *)(generic_comm_base + 1);
177 WRITE_ONCE(generic_comm_base->signature,
178 cpu_to_le32(PCC_SIGNATURE | ctx->mbox_idx));
180 WRITE_ONCE(generic_comm_base->command,
181 cpu_to_le16(SLIMPRO_MSG_TYPE(msg[0]) | PCC_CMD_GENERATE_DB_INTR));
183 status = le16_to_cpu(READ_ONCE(generic_comm_base->status));
184 status &= ~PCC_STATUS_CMD_COMPLETE;
185 WRITE_ONCE(generic_comm_base->status, cpu_to_le16(status));
187 /* Copy the message to the PCC comm space */
188 for (i = 0; i < SLIMPRO_IIC_MSG_DWORD_COUNT; i++)
189 WRITE_ONCE(ptr[i], cpu_to_le32(msg[i]));
192 static int start_i2c_msg_xfer(struct slimpro_i2c_dev *ctx)
194 if (ctx->mbox_client.tx_block || !acpi_disabled) {
195 if (!wait_for_completion_timeout(&ctx->rd_complete,
196 msecs_to_jiffies(MAILBOX_OP_TIMEOUT)))
200 /* Check of invalid data or no device */
201 if (*ctx->resp_msg == 0xffffffff)
207 static int slimpro_i2c_send_msg(struct slimpro_i2c_dev *ctx,
213 ctx->resp_msg = data;
215 if (!acpi_disabled) {
216 reinit_completion(&ctx->rd_complete);
217 slimpro_i2c_pcc_tx_prepare(ctx, msg);
220 rc = mbox_send_message(ctx->mbox_chan, msg);
224 rc = start_i2c_msg_xfer(ctx);
228 mbox_chan_txdone(ctx->mbox_chan, 0);
230 ctx->resp_msg = NULL;
235 static int slimpro_i2c_rd(struct slimpro_i2c_dev *ctx, u32 chip,
236 u32 addr, u32 addrlen, u32 protocol,
237 u32 readlen, u32 *data)
241 msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
242 SLIMPRO_IIC_READ, protocol, addrlen, readlen);
243 msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
246 return slimpro_i2c_send_msg(ctx, msg, data);
249 static int slimpro_i2c_wr(struct slimpro_i2c_dev *ctx, u32 chip,
250 u32 addr, u32 addrlen, u32 protocol, u32 writelen,
255 msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
256 SLIMPRO_IIC_WRITE, protocol, addrlen, writelen);
257 msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
260 return slimpro_i2c_send_msg(ctx, msg, msg);
263 static int slimpro_i2c_blkrd(struct slimpro_i2c_dev *ctx, u32 chip, u32 addr,
264 u32 addrlen, u32 protocol, u32 readlen,
265 u32 with_data_len, void *data)
271 paddr = dma_map_single(ctx->dev, ctx->dma_buffer, readlen, DMA_FROM_DEVICE);
272 if (dma_mapping_error(ctx->dev, paddr)) {
273 dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
278 msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_READ,
279 protocol, addrlen, readlen);
280 msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR |
281 SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(with_data_len) |
282 SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) |
283 SLIMPRO_IIC_ENCODE_ADDR(addr);
286 rc = slimpro_i2c_send_msg(ctx, msg, msg);
288 /* Copy to destination */
289 memcpy(data, ctx->dma_buffer, readlen);
291 dma_unmap_single(ctx->dev, paddr, readlen, DMA_FROM_DEVICE);
295 static int slimpro_i2c_blkwr(struct slimpro_i2c_dev *ctx, u32 chip,
296 u32 addr, u32 addrlen, u32 protocol, u32 writelen,
303 if (writelen > I2C_SMBUS_BLOCK_MAX)
306 memcpy(ctx->dma_buffer, data, writelen);
307 paddr = dma_map_single(ctx->dev, ctx->dma_buffer, writelen,
309 if (dma_mapping_error(ctx->dev, paddr)) {
310 dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
315 msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_WRITE,
316 protocol, addrlen, writelen);
317 msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR |
318 SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) |
319 SLIMPRO_IIC_ENCODE_ADDR(addr);
322 if (ctx->mbox_client.tx_block)
323 reinit_completion(&ctx->rd_complete);
325 rc = slimpro_i2c_send_msg(ctx, msg, msg);
327 dma_unmap_single(ctx->dev, paddr, writelen, DMA_TO_DEVICE);
331 static int xgene_slimpro_i2c_xfer(struct i2c_adapter *adap, u16 addr,
332 unsigned short flags, char read_write,
333 u8 command, int size,
334 union i2c_smbus_data *data)
336 struct slimpro_i2c_dev *ctx = i2c_get_adapdata(adap);
337 int ret = -EOPNOTSUPP;
342 if (read_write == I2C_SMBUS_READ) {
343 ret = slimpro_i2c_rd(ctx, addr, 0, 0,
344 SLIMPRO_IIC_SMB_PROTOCOL,
348 ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
349 SLIMPRO_IIC_SMB_PROTOCOL,
353 case I2C_SMBUS_BYTE_DATA:
354 if (read_write == I2C_SMBUS_READ) {
355 ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
356 SLIMPRO_IIC_SMB_PROTOCOL,
361 ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
362 SLIMPRO_IIC_SMB_PROTOCOL,
366 case I2C_SMBUS_WORD_DATA:
367 if (read_write == I2C_SMBUS_READ) {
368 ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
369 SLIMPRO_IIC_SMB_PROTOCOL,
374 ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
375 SLIMPRO_IIC_SMB_PROTOCOL,
379 case I2C_SMBUS_BLOCK_DATA:
380 if (read_write == I2C_SMBUS_READ) {
381 ret = slimpro_i2c_blkrd(ctx, addr, command,
383 SLIMPRO_IIC_SMB_PROTOCOL,
384 I2C_SMBUS_BLOCK_MAX + 1,
385 IIC_SMB_WITH_DATA_LEN,
389 ret = slimpro_i2c_blkwr(ctx, addr, command,
391 SLIMPRO_IIC_SMB_PROTOCOL,
396 case I2C_SMBUS_I2C_BLOCK_DATA:
397 if (read_write == I2C_SMBUS_READ) {
398 ret = slimpro_i2c_blkrd(ctx, addr,
401 SLIMPRO_IIC_I2C_PROTOCOL,
403 IIC_SMB_WITHOUT_DATA_LEN,
406 ret = slimpro_i2c_blkwr(ctx, addr, command,
408 SLIMPRO_IIC_I2C_PROTOCOL,
420 * Return list of supported functionality.
422 static u32 xgene_slimpro_i2c_func(struct i2c_adapter *adapter)
424 return I2C_FUNC_SMBUS_BYTE |
425 I2C_FUNC_SMBUS_BYTE_DATA |
426 I2C_FUNC_SMBUS_WORD_DATA |
427 I2C_FUNC_SMBUS_BLOCK_DATA |
428 I2C_FUNC_SMBUS_I2C_BLOCK;
431 static const struct i2c_algorithm xgene_slimpro_i2c_algorithm = {
432 .smbus_xfer = xgene_slimpro_i2c_xfer,
433 .functionality = xgene_slimpro_i2c_func,
436 static int xgene_slimpro_i2c_probe(struct platform_device *pdev)
438 struct slimpro_i2c_dev *ctx;
439 struct i2c_adapter *adapter;
440 struct mbox_client *cl;
443 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
447 ctx->dev = &pdev->dev;
448 platform_set_drvdata(pdev, ctx);
449 cl = &ctx->mbox_client;
451 /* Request mailbox channel */
452 cl->dev = &pdev->dev;
453 init_completion(&ctx->rd_complete);
454 cl->tx_tout = MAILBOX_OP_TIMEOUT;
455 cl->knows_txdone = false;
458 cl->rx_callback = slimpro_i2c_rx_cb;
459 ctx->mbox_chan = mbox_request_channel(cl, MAILBOX_I2C_INDEX);
460 if (IS_ERR(ctx->mbox_chan)) {
461 dev_err(&pdev->dev, "i2c mailbox channel request failed\n");
462 return PTR_ERR(ctx->mbox_chan);
465 struct pcc_mbox_chan *pcc_chan;
466 const struct acpi_device_id *acpi_id;
467 int version = XGENE_SLIMPRO_I2C_V1;
469 acpi_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
474 version = (int)acpi_id->driver_data;
476 if (device_property_read_u32(&pdev->dev, "pcc-channel",
478 ctx->mbox_idx = MAILBOX_I2C_INDEX;
480 cl->tx_block = false;
481 cl->rx_callback = slimpro_i2c_pcc_rx_cb;
482 pcc_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
483 if (IS_ERR(pcc_chan)) {
484 dev_err(&pdev->dev, "PCC mailbox channel request failed\n");
485 return PTR_ERR(pcc_chan);
488 ctx->pcc_chan = pcc_chan;
489 ctx->mbox_chan = pcc_chan->mchan;
491 if (!ctx->mbox_chan->mbox->txdone_irq) {
492 dev_err(&pdev->dev, "PCC IRQ not supported\n");
498 * This is the shared communication region
499 * for the OS and Platform to communicate over.
501 ctx->comm_base_addr = pcc_chan->shmem_base_addr;
502 if (ctx->comm_base_addr) {
503 if (version == XGENE_SLIMPRO_I2C_V2)
504 ctx->pcc_comm_addr = memremap(
506 pcc_chan->shmem_size,
509 ctx->pcc_comm_addr = memremap(
511 pcc_chan->shmem_size,
514 dev_err(&pdev->dev, "Failed to get PCC comm region\n");
519 if (!ctx->pcc_comm_addr) {
521 "Failed to ioremap PCC comm region\n");
526 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
528 dev_warn(&pdev->dev, "Unable to set dma mask\n");
530 /* Setup I2C adapter */
531 adapter = &ctx->adapter;
532 snprintf(adapter->name, sizeof(adapter->name), "MAILBOX I2C");
533 adapter->algo = &xgene_slimpro_i2c_algorithm;
534 adapter->class = I2C_CLASS_HWMON;
535 adapter->dev.parent = &pdev->dev;
536 adapter->dev.of_node = pdev->dev.of_node;
537 ACPI_COMPANION_SET(&adapter->dev, ACPI_COMPANION(&pdev->dev));
538 i2c_set_adapdata(adapter, ctx);
539 rc = i2c_add_adapter(adapter);
543 dev_info(&pdev->dev, "Mailbox I2C Adapter registered\n");
548 mbox_free_channel(ctx->mbox_chan);
550 pcc_mbox_free_channel(ctx->pcc_chan);
555 static void xgene_slimpro_i2c_remove(struct platform_device *pdev)
557 struct slimpro_i2c_dev *ctx = platform_get_drvdata(pdev);
559 i2c_del_adapter(&ctx->adapter);
562 mbox_free_channel(ctx->mbox_chan);
564 pcc_mbox_free_channel(ctx->pcc_chan);
567 static const struct of_device_id xgene_slimpro_i2c_dt_ids[] = {
568 {.compatible = "apm,xgene-slimpro-i2c" },
571 MODULE_DEVICE_TABLE(of, xgene_slimpro_i2c_dt_ids);
574 static const struct acpi_device_id xgene_slimpro_i2c_acpi_ids[] = {
575 {"APMC0D40", XGENE_SLIMPRO_I2C_V1},
576 {"APMC0D8B", XGENE_SLIMPRO_I2C_V2},
579 MODULE_DEVICE_TABLE(acpi, xgene_slimpro_i2c_acpi_ids);
582 static struct platform_driver xgene_slimpro_i2c_driver = {
583 .probe = xgene_slimpro_i2c_probe,
584 .remove = xgene_slimpro_i2c_remove,
586 .name = "xgene-slimpro-i2c",
587 .of_match_table = of_match_ptr(xgene_slimpro_i2c_dt_ids),
588 .acpi_match_table = ACPI_PTR(xgene_slimpro_i2c_acpi_ids)
592 module_platform_driver(xgene_slimpro_i2c_driver);
594 MODULE_DESCRIPTION("APM X-Gene SLIMpro I2C driver");
597 MODULE_LICENSE("GPL");