1 // SPDX-License-Identifier: GPL-2.0
3 * HiSilicon I2C Controller Driver for Kunpeng SoC
5 * Copyright (c) 2021 HiSilicon Technologies Co., Ltd.
8 #include <linux/bits.h>
9 #include <linux/bitfield.h>
10 #include <linux/completion.h>
11 #include <linux/i2c.h>
12 #include <linux/interrupt.h>
14 #include <linux/module.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/platform_device.h>
17 #include <linux/property.h>
18 #include <linux/units.h>
20 #define HISI_I2C_FRAME_CTRL 0x0000
21 #define HISI_I2C_FRAME_CTRL_SPEED_MODE GENMASK(1, 0)
22 #define HISI_I2C_FRAME_CTRL_ADDR_TEN BIT(2)
23 #define HISI_I2C_SLV_ADDR 0x0004
24 #define HISI_I2C_SLV_ADDR_VAL GENMASK(9, 0)
25 #define HISI_I2C_SLV_ADDR_GC_S_MODE BIT(10)
26 #define HISI_I2C_SLV_ADDR_GC_S_EN BIT(11)
27 #define HISI_I2C_CMD_TXDATA 0x0008
28 #define HISI_I2C_CMD_TXDATA_DATA GENMASK(7, 0)
29 #define HISI_I2C_CMD_TXDATA_RW BIT(8)
30 #define HISI_I2C_CMD_TXDATA_P_EN BIT(9)
31 #define HISI_I2C_CMD_TXDATA_SR_EN BIT(10)
32 #define HISI_I2C_RXDATA 0x000c
33 #define HISI_I2C_RXDATA_DATA GENMASK(7, 0)
34 #define HISI_I2C_SS_SCL_HCNT 0x0010
35 #define HISI_I2C_SS_SCL_LCNT 0x0014
36 #define HISI_I2C_FS_SCL_HCNT 0x0018
37 #define HISI_I2C_FS_SCL_LCNT 0x001c
38 #define HISI_I2C_HS_SCL_HCNT 0x0020
39 #define HISI_I2C_HS_SCL_LCNT 0x0024
40 #define HISI_I2C_FIFO_CTRL 0x0028
41 #define HISI_I2C_FIFO_RX_CLR BIT(0)
42 #define HISI_I2C_FIFO_TX_CLR BIT(1)
43 #define HISI_I2C_FIFO_RX_AF_THRESH GENMASK(7, 2)
44 #define HISI_I2C_FIFO_TX_AE_THRESH GENMASK(13, 8)
45 #define HISI_I2C_FIFO_STATE 0x002c
46 #define HISI_I2C_FIFO_STATE_RX_RERR BIT(0)
47 #define HISI_I2C_FIFO_STATE_RX_WERR BIT(1)
48 #define HISI_I2C_FIFO_STATE_RX_EMPTY BIT(3)
49 #define HISI_I2C_FIFO_STATE_TX_RERR BIT(6)
50 #define HISI_I2C_FIFO_STATE_TX_WERR BIT(7)
51 #define HISI_I2C_FIFO_STATE_TX_FULL BIT(11)
52 #define HISI_I2C_SDA_HOLD 0x0030
53 #define HISI_I2C_SDA_HOLD_TX GENMASK(15, 0)
54 #define HISI_I2C_SDA_HOLD_RX GENMASK(23, 16)
55 #define HISI_I2C_FS_SPK_LEN 0x0038
56 #define HISI_I2C_FS_SPK_LEN_CNT GENMASK(7, 0)
57 #define HISI_I2C_HS_SPK_LEN 0x003c
58 #define HISI_I2C_HS_SPK_LEN_CNT GENMASK(7, 0)
59 #define HISI_I2C_INT_MSTAT 0x0044
60 #define HISI_I2C_INT_CLR 0x0048
61 #define HISI_I2C_INT_MASK 0x004C
62 #define HISI_I2C_TRANS_STATE 0x0050
63 #define HISI_I2C_TRANS_ERR 0x0054
64 #define HISI_I2C_VERSION 0x0058
66 #define HISI_I2C_INT_ALL GENMASK(4, 0)
67 #define HISI_I2C_INT_TRANS_CPLT BIT(0)
68 #define HISI_I2C_INT_TRANS_ERR BIT(1)
69 #define HISI_I2C_INT_FIFO_ERR BIT(2)
70 #define HISI_I2C_INT_RX_FULL BIT(3)
71 #define HISI_I2C_INT_TX_EMPTY BIT(4)
72 #define HISI_I2C_INT_ERR \
73 (HISI_I2C_INT_TRANS_ERR | HISI_I2C_INT_FIFO_ERR)
75 #define HISI_I2C_STD_SPEED_MODE 0
76 #define HISI_I2C_FAST_SPEED_MODE 1
77 #define HISI_I2C_HIGH_SPEED_MODE 2
79 #define HISI_I2C_TX_FIFO_DEPTH 64
80 #define HISI_I2C_RX_FIFO_DEPTH 64
81 #define HISI_I2C_TX_F_AE_THRESH 1
82 #define HISI_I2C_RX_F_AF_THRESH 60
84 #define NSEC_TO_CYCLES(ns, clk_rate_khz) \
85 DIV_ROUND_UP_ULL((clk_rate_khz) * (ns), NSEC_PER_MSEC)
87 struct hisi_i2c_controller {
88 struct i2c_adapter adapter;
93 /* Intermediates for recording the transfer process */
94 struct completion *completion;
104 /* I2C bus configuration */
105 struct i2c_timings t;
110 static void hisi_i2c_enable_int(struct hisi_i2c_controller *ctlr, u32 mask)
112 writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_MASK);
115 static void hisi_i2c_disable_int(struct hisi_i2c_controller *ctlr, u32 mask)
117 writel_relaxed((~mask) & HISI_I2C_INT_ALL, ctlr->iobase + HISI_I2C_INT_MASK);
120 static void hisi_i2c_clear_int(struct hisi_i2c_controller *ctlr, u32 mask)
122 writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_CLR);
125 static void hisi_i2c_handle_errors(struct hisi_i2c_controller *ctlr)
127 u32 int_err = ctlr->xfer_err, reg;
129 if (int_err & HISI_I2C_INT_FIFO_ERR) {
130 reg = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
132 if (reg & HISI_I2C_FIFO_STATE_RX_RERR)
133 dev_err(ctlr->dev, "rx fifo error read\n");
135 if (reg & HISI_I2C_FIFO_STATE_RX_WERR)
136 dev_err(ctlr->dev, "rx fifo error write\n");
138 if (reg & HISI_I2C_FIFO_STATE_TX_RERR)
139 dev_err(ctlr->dev, "tx fifo error read\n");
141 if (reg & HISI_I2C_FIFO_STATE_TX_WERR)
142 dev_err(ctlr->dev, "tx fifo error write\n");
146 static int hisi_i2c_start_xfer(struct hisi_i2c_controller *ctlr)
148 struct i2c_msg *msg = ctlr->msgs;
151 reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL);
152 reg &= ~HISI_I2C_FRAME_CTRL_ADDR_TEN;
153 if (msg->flags & I2C_M_TEN)
154 reg |= HISI_I2C_FRAME_CTRL_ADDR_TEN;
155 writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL);
157 reg = readl(ctlr->iobase + HISI_I2C_SLV_ADDR);
158 reg &= ~HISI_I2C_SLV_ADDR_VAL;
159 reg |= FIELD_PREP(HISI_I2C_SLV_ADDR_VAL, msg->addr);
160 writel(reg, ctlr->iobase + HISI_I2C_SLV_ADDR);
162 reg = readl(ctlr->iobase + HISI_I2C_FIFO_CTRL);
163 reg |= HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR;
164 writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
165 reg &= ~(HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR);
166 writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
168 hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
169 hisi_i2c_enable_int(ctlr, HISI_I2C_INT_ALL);
174 static void hisi_i2c_reset_xfer(struct hisi_i2c_controller *ctlr)
178 ctlr->msg_tx_idx = 0;
179 ctlr->msg_rx_idx = 0;
180 ctlr->buf_tx_idx = 0;
181 ctlr->buf_rx_idx = 0;
185 * Initialize the transfer information and start the I2C bus transfer.
186 * We only configure the transfer and do some pre/post works here, and
187 * wait for the transfer done. The major transfer process is performed
188 * in the IRQ handler.
190 static int hisi_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
193 struct hisi_i2c_controller *ctlr = i2c_get_adapdata(adap);
194 DECLARE_COMPLETION_ONSTACK(done);
197 hisi_i2c_reset_xfer(ctlr);
198 ctlr->completion = &done;
202 hisi_i2c_start_xfer(ctlr);
204 if (!wait_for_completion_timeout(ctlr->completion, adap->timeout)) {
205 hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
206 synchronize_irq(ctlr->irq);
207 i2c_recover_bus(&ctlr->adapter);
208 dev_err(ctlr->dev, "bus transfer timeout\n");
212 if (ctlr->xfer_err) {
213 hisi_i2c_handle_errors(ctlr);
217 hisi_i2c_reset_xfer(ctlr);
218 ctlr->completion = NULL;
223 static u32 hisi_i2c_functionality(struct i2c_adapter *adap)
225 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
228 static const struct i2c_algorithm hisi_i2c_algo = {
229 .master_xfer = hisi_i2c_master_xfer,
230 .functionality = hisi_i2c_functionality,
233 static int hisi_i2c_read_rx_fifo(struct hisi_i2c_controller *ctlr)
235 struct i2c_msg *cur_msg;
238 while (ctlr->msg_rx_idx < ctlr->msg_num) {
239 cur_msg = ctlr->msgs + ctlr->msg_rx_idx;
241 if (!(cur_msg->flags & I2C_M_RD)) {
246 fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
247 while (!(fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY) &&
248 ctlr->buf_rx_idx < cur_msg->len) {
249 cur_msg->buf[ctlr->buf_rx_idx++] = readl(ctlr->iobase + HISI_I2C_RXDATA);
250 fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
253 if (ctlr->buf_rx_idx == cur_msg->len) {
254 ctlr->buf_rx_idx = 0;
258 if (fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY)
265 static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr)
267 int max_write = HISI_I2C_TX_FIFO_DEPTH;
268 bool need_restart = false, last_msg;
269 struct i2c_msg *cur_msg;
272 while (ctlr->msg_tx_idx < ctlr->msg_num) {
273 cur_msg = ctlr->msgs + ctlr->msg_tx_idx;
274 last_msg = (ctlr->msg_tx_idx == ctlr->msg_num - 1);
276 /* Signal the SR bit when we start transferring a new message */
277 if (ctlr->msg_tx_idx && !ctlr->buf_tx_idx)
280 fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
281 while (!(fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) &&
282 ctlr->buf_tx_idx < cur_msg->len && max_write) {
286 cmd |= HISI_I2C_CMD_TXDATA_SR_EN;
287 need_restart = false;
290 /* Signal the STOP bit at the last frame of the last message */
291 if (ctlr->buf_tx_idx == cur_msg->len - 1 && last_msg)
292 cmd |= HISI_I2C_CMD_TXDATA_P_EN;
294 if (cur_msg->flags & I2C_M_RD)
295 cmd |= HISI_I2C_CMD_TXDATA_RW;
297 cmd |= FIELD_PREP(HISI_I2C_CMD_TXDATA_DATA,
298 cur_msg->buf[ctlr->buf_tx_idx]);
300 writel(cmd, ctlr->iobase + HISI_I2C_CMD_TXDATA);
304 fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
307 /* Update the transfer index after per message transfer is done. */
308 if (ctlr->buf_tx_idx == cur_msg->len) {
309 ctlr->buf_tx_idx = 0;
313 if ((fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) ||
319 static irqreturn_t hisi_i2c_irq(int irq, void *context)
321 struct hisi_i2c_controller *ctlr = context;
324 int_stat = readl(ctlr->iobase + HISI_I2C_INT_MSTAT);
325 hisi_i2c_clear_int(ctlr, int_stat);
326 if (!(int_stat & HISI_I2C_INT_ALL))
329 if (int_stat & HISI_I2C_INT_TX_EMPTY)
330 hisi_i2c_xfer_msg(ctlr);
332 if (int_stat & HISI_I2C_INT_ERR) {
333 ctlr->xfer_err = int_stat;
337 /* Drain the rx fifo before finish the transfer */
338 if (int_stat & (HISI_I2C_INT_TRANS_CPLT | HISI_I2C_INT_RX_FULL))
339 hisi_i2c_read_rx_fifo(ctlr);
342 if (int_stat & HISI_I2C_INT_TRANS_CPLT || ctlr->xfer_err) {
343 hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
344 hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
345 complete(ctlr->completion);
352 * Helper function for calculating and configuring the HIGH and LOW
353 * periods of SCL clock. The caller will pass the ratio of the
354 * counts (divide / divisor) according to the target speed mode,
355 * and the target registers.
357 static void hisi_i2c_set_scl(struct hisi_i2c_controller *ctlr,
358 u32 divide, u32 divisor,
359 u32 reg_hcnt, u32 reg_lcnt)
361 u32 total_cnt, t_scl_hcnt, t_scl_lcnt, scl_fall_cnt, scl_rise_cnt;
362 u32 scl_hcnt, scl_lcnt;
364 /* Total SCL clock cycles per speed period */
365 total_cnt = DIV_ROUND_UP_ULL(ctlr->clk_rate_khz * HZ_PER_KHZ, ctlr->t.bus_freq_hz);
366 /* Total HIGH level SCL clock cycles including edges */
367 t_scl_hcnt = DIV_ROUND_UP_ULL(total_cnt * divide, divisor);
368 /* Total LOW level SCL clock cycles including edges */
369 t_scl_lcnt = total_cnt - t_scl_hcnt;
370 /* Fall edge SCL clock cycles */
371 scl_fall_cnt = NSEC_TO_CYCLES(ctlr->t.scl_fall_ns, ctlr->clk_rate_khz);
372 /* Rise edge SCL clock cycles */
373 scl_rise_cnt = NSEC_TO_CYCLES(ctlr->t.scl_rise_ns, ctlr->clk_rate_khz);
375 /* Calculated HIGH and LOW periods of SCL clock */
376 scl_hcnt = t_scl_hcnt - ctlr->spk_len - 7 - scl_fall_cnt;
377 scl_lcnt = t_scl_lcnt - 1 - scl_rise_cnt;
379 writel(scl_hcnt, ctlr->iobase + reg_hcnt);
380 writel(scl_lcnt, ctlr->iobase + reg_lcnt);
383 static void hisi_i2c_configure_bus(struct hisi_i2c_controller *ctlr)
385 u32 reg, sda_hold_cnt, speed_mode;
387 i2c_parse_fw_timings(ctlr->dev, &ctlr->t, true);
388 ctlr->spk_len = NSEC_TO_CYCLES(ctlr->t.digital_filter_width_ns, ctlr->clk_rate_khz);
390 switch (ctlr->t.bus_freq_hz) {
391 case I2C_MAX_FAST_MODE_FREQ:
392 speed_mode = HISI_I2C_FAST_SPEED_MODE;
393 hisi_i2c_set_scl(ctlr, 26, 76, HISI_I2C_FS_SCL_HCNT, HISI_I2C_FS_SCL_LCNT);
395 case I2C_MAX_HIGH_SPEED_MODE_FREQ:
396 speed_mode = HISI_I2C_HIGH_SPEED_MODE;
397 hisi_i2c_set_scl(ctlr, 6, 22, HISI_I2C_HS_SCL_HCNT, HISI_I2C_HS_SCL_LCNT);
399 case I2C_MAX_STANDARD_MODE_FREQ:
401 speed_mode = HISI_I2C_STD_SPEED_MODE;
403 /* For default condition force the bus speed to standard mode. */
404 ctlr->t.bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
405 hisi_i2c_set_scl(ctlr, 40, 87, HISI_I2C_SS_SCL_HCNT, HISI_I2C_SS_SCL_LCNT);
409 reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL);
410 reg &= ~HISI_I2C_FRAME_CTRL_SPEED_MODE;
411 reg |= FIELD_PREP(HISI_I2C_FRAME_CTRL_SPEED_MODE, speed_mode);
412 writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL);
414 sda_hold_cnt = NSEC_TO_CYCLES(ctlr->t.sda_hold_ns, ctlr->clk_rate_khz);
416 reg = FIELD_PREP(HISI_I2C_SDA_HOLD_TX, sda_hold_cnt);
417 writel(reg, ctlr->iobase + HISI_I2C_SDA_HOLD);
419 writel(ctlr->spk_len, ctlr->iobase + HISI_I2C_FS_SPK_LEN);
421 reg = FIELD_PREP(HISI_I2C_FIFO_RX_AF_THRESH, HISI_I2C_RX_F_AF_THRESH);
422 reg |= FIELD_PREP(HISI_I2C_FIFO_TX_AE_THRESH, HISI_I2C_TX_F_AE_THRESH);
423 writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
426 static int hisi_i2c_probe(struct platform_device *pdev)
428 struct hisi_i2c_controller *ctlr;
429 struct device *dev = &pdev->dev;
430 struct i2c_adapter *adapter;
435 ctlr = devm_kzalloc(dev, sizeof(*ctlr), GFP_KERNEL);
439 ctlr->iobase = devm_platform_ioremap_resource(pdev, 0);
440 if (IS_ERR(ctlr->iobase))
441 return PTR_ERR(ctlr->iobase);
443 ctlr->irq = platform_get_irq(pdev, 0);
449 hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
451 ret = devm_request_irq(dev, ctlr->irq, hisi_i2c_irq, 0, "hisi-i2c", ctlr);
453 dev_err(dev, "failed to request irq handler, ret = %d\n", ret);
457 ret = device_property_read_u64(dev, "clk_rate", &clk_rate_hz);
459 dev_err(dev, "failed to get clock frequency, ret = %d\n", ret);
463 ctlr->clk_rate_khz = DIV_ROUND_UP_ULL(clk_rate_hz, HZ_PER_KHZ);
465 hisi_i2c_configure_bus(ctlr);
467 adapter = &ctlr->adapter;
468 snprintf(adapter->name, sizeof(adapter->name),
469 "HiSilicon I2C Controller %s", dev_name(dev));
470 adapter->owner = THIS_MODULE;
471 adapter->algo = &hisi_i2c_algo;
472 adapter->dev.parent = dev;
473 i2c_set_adapdata(adapter, ctlr);
475 ret = devm_i2c_add_adapter(dev, adapter);
479 hw_version = readl(ctlr->iobase + HISI_I2C_VERSION);
480 dev_info(ctlr->dev, "speed mode is %s. hw version 0x%x\n",
481 i2c_freq_mode_string(ctlr->t.bus_freq_hz), hw_version);
486 static const struct acpi_device_id hisi_i2c_acpi_ids[] = {
490 MODULE_DEVICE_TABLE(acpi, hisi_i2c_acpi_ids);
492 static const struct of_device_id hisi_i2c_dts_ids[] = {
493 { .compatible = "hisilicon,ascend910-i2c", },
496 MODULE_DEVICE_TABLE(of, hisi_i2c_dts_ids);
498 static struct platform_driver hisi_i2c_driver = {
499 .probe = hisi_i2c_probe,
502 .acpi_match_table = hisi_i2c_acpi_ids,
503 .of_match_table = hisi_i2c_dts_ids,
506 module_platform_driver(hisi_i2c_driver);
508 MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
509 MODULE_DESCRIPTION("HiSilicon I2C Controller Driver");
510 MODULE_LICENSE("GPL");