1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Synopsys DesignWare I2C adapter driver.
5 * Based on the TI DAVINCI I2C adapter driver.
7 * Copyright (C) 2006 Texas Instruments.
8 * Copyright (C) 2007 MontaVista Software Inc.
9 * Copyright (C) 2009 Provigent Ltd.
11 #include <linux/acpi.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/errno.h>
17 #include <linux/export.h>
18 #include <linux/i2c.h>
19 #include <linux/interrupt.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/property.h>
27 #include <linux/regmap.h>
28 #include <linux/swab.h>
29 #include <linux/types.h>
30 #include <linux/units.h>
32 #define DEFAULT_SYMBOL_NAMESPACE "I2C_DW_COMMON"
34 #include "i2c-designware-core.h"
36 static const char *const abort_sources[] = {
37 [ABRT_7B_ADDR_NOACK] =
38 "slave address not acknowledged (7bit mode)",
39 [ABRT_10ADDR1_NOACK] =
40 "first address byte not acknowledged (10bit mode)",
41 [ABRT_10ADDR2_NOACK] =
42 "second address byte not acknowledged (10bit mode)",
44 "data not acknowledged",
46 "no acknowledgement for a general call",
48 "read after general call",
50 "start byte acknowledged",
51 [ABRT_SBYTE_NORSTRT] =
52 "trying to send start byte when restart is disabled",
53 [ABRT_10B_RD_NORSTRT] =
54 "trying to read when restart is disabled (10bit mode)",
56 "trying to use disabled adapter",
59 [ABRT_SLAVE_FLUSH_TXFIFO] =
60 "read command so flush old data in the TX FIFO",
61 [ABRT_SLAVE_ARBLOST] =
62 "slave lost the bus while transmitting data to a remote master",
63 [ABRT_SLAVE_RD_INTX] =
64 "incorrect slave-transmitter mode configuration",
67 static int dw_reg_read(void *context, unsigned int reg, unsigned int *val)
69 struct dw_i2c_dev *dev = context;
71 *val = readl(dev->base + reg);
76 static int dw_reg_write(void *context, unsigned int reg, unsigned int val)
78 struct dw_i2c_dev *dev = context;
80 writel(val, dev->base + reg);
85 static int dw_reg_read_swab(void *context, unsigned int reg, unsigned int *val)
87 struct dw_i2c_dev *dev = context;
89 *val = swab32(readl(dev->base + reg));
94 static int dw_reg_write_swab(void *context, unsigned int reg, unsigned int val)
96 struct dw_i2c_dev *dev = context;
98 writel(swab32(val), dev->base + reg);
103 static int dw_reg_read_word(void *context, unsigned int reg, unsigned int *val)
105 struct dw_i2c_dev *dev = context;
107 *val = readw(dev->base + reg) |
108 (readw(dev->base + reg + 2) << 16);
113 static int dw_reg_write_word(void *context, unsigned int reg, unsigned int val)
115 struct dw_i2c_dev *dev = context;
117 writew(val, dev->base + reg);
118 writew(val >> 16, dev->base + reg + 2);
124 * i2c_dw_init_regmap() - Initialize registers map
125 * @dev: device private data
127 * Autodetects needed register access mode and creates the regmap with
128 * corresponding read/write callbacks. This must be called before doing any
129 * other register access.
131 * Return: 0 on success, or negative errno otherwise.
133 int i2c_dw_init_regmap(struct dw_i2c_dev *dev)
135 struct regmap_config map_cfg = {
139 .disable_locking = true,
140 .reg_read = dw_reg_read,
141 .reg_write = dw_reg_write,
142 .max_register = DW_IC_COMP_TYPE,
148 * Skip detecting the registers map configuration if the regmap has
149 * already been provided by a higher code.
154 ret = i2c_dw_acquire_lock(dev);
158 reg = readl(dev->base + DW_IC_COMP_TYPE);
159 i2c_dw_release_lock(dev);
161 if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU)
162 map_cfg.max_register = AMD_UCSI_INTR_REG;
164 if (reg == swab32(DW_IC_COMP_TYPE_VALUE)) {
165 map_cfg.reg_read = dw_reg_read_swab;
166 map_cfg.reg_write = dw_reg_write_swab;
167 } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
168 map_cfg.reg_read = dw_reg_read_word;
169 map_cfg.reg_write = dw_reg_write_word;
170 } else if (reg != DW_IC_COMP_TYPE_VALUE) {
172 "Unknown Synopsys component type: 0x%08x\n", reg);
177 * Note we'll check the return value of the regmap IO accessors only
178 * at the probe stage. The rest of the code won't do this because
179 * basically we have MMIO-based regmap, so none of the read/write methods
182 dev->map = devm_regmap_init(dev->dev, NULL, dev, &map_cfg);
183 if (IS_ERR(dev->map)) {
184 dev_err(dev->dev, "Failed to init the registers map\n");
185 return PTR_ERR(dev->map);
191 static const u32 supported_speeds[] = {
192 I2C_MAX_HIGH_SPEED_MODE_FREQ,
193 I2C_MAX_FAST_MODE_PLUS_FREQ,
194 I2C_MAX_FAST_MODE_FREQ,
195 I2C_MAX_STANDARD_MODE_FREQ,
198 static int i2c_dw_validate_speed(struct dw_i2c_dev *dev)
200 struct i2c_timings *t = &dev->timings;
204 * Only standard mode at 100kHz, fast mode at 400kHz,
205 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
207 for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) {
208 if (t->bus_freq_hz == supported_speeds[i])
213 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
221 #include <linux/platform_device.h>
223 #define MSCC_ICPU_CFG_TWI_DELAY 0x0
224 #define MSCC_ICPU_CFG_TWI_DELAY_ENABLE BIT(0)
225 #define MSCC_ICPU_CFG_TWI_SPIKE_FILTER 0x4
227 static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
229 writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE,
230 dev->ext + MSCC_ICPU_CFG_TWI_DELAY);
235 static void i2c_dw_of_configure(struct device *device)
237 struct platform_device *pdev = to_platform_device(device);
238 struct dw_i2c_dev *dev = dev_get_drvdata(device);
240 switch (dev->flags & MODEL_MASK) {
241 case MODEL_MSCC_OCELOT:
242 dev->ext = devm_platform_ioremap_resource(pdev, 1);
243 if (!IS_ERR(dev->ext))
244 dev->set_sda_hold_time = mscc_twi_set_sda_hold_time;
251 #else /* CONFIG_OF */
253 static inline void i2c_dw_of_configure(struct device *device) { }
255 #endif /* CONFIG_OF */
259 #include <linux/dmi.h>
262 * The HCNT/LCNT information coming from ACPI should be the most accurate
263 * for given platform. However, some systems get it wrong. On such systems
264 * we get better results by calculating those based on the input clock.
266 static const struct dmi_system_id i2c_dw_no_acpi_params[] = {
268 .ident = "Dell Inspiron 7348",
270 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
271 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
277 static void i2c_dw_acpi_params(struct device *device, char method[],
278 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
280 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
281 acpi_handle handle = ACPI_HANDLE(device);
282 union acpi_object *obj;
284 if (dmi_check_system(i2c_dw_no_acpi_params))
287 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
290 obj = (union acpi_object *)buf.pointer;
291 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
292 const union acpi_object *objs = obj->package.elements;
294 *hcnt = (u16)objs[0].integer.value;
295 *lcnt = (u16)objs[1].integer.value;
296 *sda_hold = (u32)objs[2].integer.value;
302 static void i2c_dw_acpi_configure(struct device *device)
304 struct dw_i2c_dev *dev = dev_get_drvdata(device);
305 struct i2c_timings *t = &dev->timings;
306 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
309 * Try to get SDA hold time and *CNT values from an ACPI method for
310 * selected speed modes.
312 i2c_dw_acpi_params(device, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
313 i2c_dw_acpi_params(device, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
314 i2c_dw_acpi_params(device, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
315 i2c_dw_acpi_params(device, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
317 switch (t->bus_freq_hz) {
318 case I2C_MAX_STANDARD_MODE_FREQ:
319 dev->sda_hold_time = ss_ht;
321 case I2C_MAX_FAST_MODE_PLUS_FREQ:
322 dev->sda_hold_time = fp_ht;
324 case I2C_MAX_HIGH_SPEED_MODE_FREQ:
325 dev->sda_hold_time = hs_ht;
327 case I2C_MAX_FAST_MODE_FREQ:
329 dev->sda_hold_time = fs_ht;
334 static u32 i2c_dw_acpi_round_bus_speed(struct device *device)
339 acpi_speed = i2c_acpi_find_bus_speed(device);
341 * Some DSDTs use a non standard speed, round down to the lowest
344 for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) {
345 if (acpi_speed >= supported_speeds[i])
346 return supported_speeds[i];
352 #else /* CONFIG_ACPI */
354 static inline void i2c_dw_acpi_configure(struct device *device) { }
356 static inline u32 i2c_dw_acpi_round_bus_speed(struct device *device) { return 0; }
358 #endif /* CONFIG_ACPI */
360 static void i2c_dw_adjust_bus_speed(struct dw_i2c_dev *dev)
362 u32 acpi_speed = i2c_dw_acpi_round_bus_speed(dev->dev);
363 struct i2c_timings *t = &dev->timings;
366 * Find bus speed from the "clock-frequency" device property, ACPI
367 * or by using fast mode if neither is set.
369 if (acpi_speed && t->bus_freq_hz)
370 t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed);
371 else if (acpi_speed || t->bus_freq_hz)
372 t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed);
374 t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
377 int i2c_dw_fw_parse_and_configure(struct dw_i2c_dev *dev)
379 struct i2c_timings *t = &dev->timings;
380 struct device *device = dev->dev;
381 struct fwnode_handle *fwnode = dev_fwnode(device);
383 i2c_parse_fw_timings(device, t, false);
385 if (device_property_read_u32(device, "snps,bus-capacitance-pf", &dev->bus_capacitance_pF))
386 dev->bus_capacitance_pF = 100;
388 dev->clk_freq_optimized = device_property_read_bool(device, "snps,clk-freq-optimized");
390 i2c_dw_adjust_bus_speed(dev);
392 if (is_of_node(fwnode))
393 i2c_dw_of_configure(device);
394 else if (is_acpi_node(fwnode))
395 i2c_dw_acpi_configure(device);
397 return i2c_dw_validate_speed(dev);
399 EXPORT_SYMBOL_GPL(i2c_dw_fw_parse_and_configure);
401 static u32 i2c_dw_read_scl_reg(struct dw_i2c_dev *dev, u32 reg)
406 ret = i2c_dw_acquire_lock(dev);
410 ret = regmap_read(dev->map, reg, &val);
411 i2c_dw_release_lock(dev);
413 return ret ? 0 : val;
416 u32 i2c_dw_scl_hcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk,
417 u32 tSYMBOL, u32 tf, int offset)
420 return i2c_dw_read_scl_reg(dev, reg);
423 * Conditional expression:
425 * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
427 * This is just experimental rule; the tHD;STA period turned
428 * out to be proportinal to (_HCNT + 3). With this setting,
429 * we could meet both tHIGH and tHD;STA timing specs.
431 * If unsure, you'd better to take this alternative.
433 * The reason why we need to take into account "tf" here,
434 * is the same as described in i2c_dw_scl_lcnt().
436 return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tSYMBOL + tf), MICRO) - 3 + offset;
439 u32 i2c_dw_scl_lcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk,
440 u32 tLOW, u32 tf, int offset)
443 return i2c_dw_read_scl_reg(dev, reg);
446 * Conditional expression:
448 * IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
450 * DW I2C core starts counting the SCL CNTs for the LOW period
451 * of the SCL clock (tLOW) as soon as it pulls the SCL line.
452 * In order to meet the tLOW timing spec, we need to take into
453 * account the fall time of SCL signal (tf). Default tf value
454 * should be 0.3 us, for safety.
456 return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tLOW + tf), MICRO) - 1 + offset;
459 int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
464 ret = i2c_dw_acquire_lock(dev);
468 /* Configure SDA Hold Time if required */
469 ret = regmap_read(dev->map, DW_IC_COMP_VERSION, ®);
471 goto err_release_lock;
473 if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
474 if (!dev->sda_hold_time) {
475 /* Keep previous hold time setting if no one set it */
476 ret = regmap_read(dev->map, DW_IC_SDA_HOLD,
477 &dev->sda_hold_time);
479 goto err_release_lock;
483 * Workaround for avoiding TX arbitration lost in case I2C
484 * slave pulls SDA down "too quickly" after falling edge of
485 * SCL by enabling non-zero SDA RX hold. Specification says it
486 * extends incoming SDA low to high transition while SCL is
487 * high but it appears to help also above issue.
489 if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
490 dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
492 dev_dbg(dev->dev, "SDA Hold Time TX:RX = %d:%d\n",
493 dev->sda_hold_time & ~(u32)DW_IC_SDA_HOLD_RX_MASK,
494 dev->sda_hold_time >> DW_IC_SDA_HOLD_RX_SHIFT);
495 } else if (dev->set_sda_hold_time) {
496 dev->set_sda_hold_time(dev);
497 } else if (dev->sda_hold_time) {
499 "Hardware too old to adjust SDA hold time.\n");
500 dev->sda_hold_time = 0;
504 i2c_dw_release_lock(dev);
509 void __i2c_dw_disable(struct dw_i2c_dev *dev)
511 struct i2c_timings *t = &dev->timings;
512 unsigned int raw_intr_stats, ic_stats;
519 regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_intr_stats);
520 regmap_read(dev->map, DW_IC_STATUS, &ic_stats);
521 regmap_read(dev->map, DW_IC_ENABLE, &enable);
523 abort_needed = (raw_intr_stats & DW_IC_INTR_MST_ON_HOLD) ||
524 (ic_stats & DW_IC_STATUS_MASTER_HOLD_TX_FIFO_EMPTY);
526 if (!(enable & DW_IC_ENABLE_ENABLE)) {
527 regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);
529 * Wait 10 times the signaling period of the highest I2C
530 * transfer supported by the driver (for 400KHz this is
531 * 25us) to ensure the I2C ENABLE bit is already set
532 * as described in the DesignWare I2C databook.
534 fsleep(DIV_ROUND_CLOSEST_ULL(10 * MICRO, t->bus_freq_hz));
535 /* Set ENABLE bit before setting ABORT */
536 enable |= DW_IC_ENABLE_ENABLE;
539 regmap_write(dev->map, DW_IC_ENABLE, enable | DW_IC_ENABLE_ABORT);
540 ret = regmap_read_poll_timeout(dev->map, DW_IC_ENABLE, enable,
541 !(enable & DW_IC_ENABLE_ABORT), 10,
544 dev_err(dev->dev, "timeout while trying to abort current transfer\n");
548 __i2c_dw_disable_nowait(dev);
550 * The enable status register may be unimplemented, but
551 * in that case this test reads zero and exits the loop.
553 regmap_read(dev->map, DW_IC_ENABLE_STATUS, &status);
554 if ((status & 1) == 0)
558 * Wait 10 times the signaling period of the highest I2C
559 * transfer supported by the driver (for 400kHz this is
560 * 25us) as described in the DesignWare I2C databook.
562 usleep_range(25, 250);
565 dev_warn(dev->dev, "timeout in disabling adapter\n");
568 u32 i2c_dw_clk_rate(struct dw_i2c_dev *dev)
571 * Clock is not necessary if we got LCNT/HCNT values directly from
574 if (WARN_ON_ONCE(!dev->get_clk_rate_khz))
576 return dev->get_clk_rate_khz(dev);
579 int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare)
584 /* Optional interface clock */
585 ret = clk_prepare_enable(dev->pclk);
589 ret = clk_prepare_enable(dev->clk);
591 clk_disable_unprepare(dev->pclk);
596 clk_disable_unprepare(dev->clk);
597 clk_disable_unprepare(dev->pclk);
601 EXPORT_SYMBOL_GPL(i2c_dw_prepare_clk);
603 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev)
607 if (!dev->acquire_lock)
610 ret = dev->acquire_lock();
614 dev_err(dev->dev, "couldn't acquire bus ownership\n");
619 void i2c_dw_release_lock(struct dw_i2c_dev *dev)
621 if (dev->release_lock)
626 * Waiting for bus not busy
628 int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
633 ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
634 !(status & DW_IC_STATUS_ACTIVITY),
637 dev_warn(dev->dev, "timeout waiting for bus ready\n");
639 i2c_recover_bus(&dev->adapter);
641 regmap_read(dev->map, DW_IC_STATUS, &status);
642 if (!(status & DW_IC_STATUS_ACTIVITY))
649 int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
651 unsigned long abort_source = dev->abort_source;
654 if (abort_source & DW_IC_TX_ABRT_NOACK) {
655 for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
657 "%s: %s\n", __func__, abort_sources[i]);
661 for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
662 dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
664 if (abort_source & DW_IC_TX_ARB_LOST)
666 if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
667 return -EINVAL; /* wrong msgs[] data */
672 int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
674 u32 tx_fifo_depth, rx_fifo_depth;
678 /* DW_IC_COMP_PARAM_1 not implement for IP issue */
679 if ((dev->flags & MODEL_MASK) == MODEL_WANGXUN_SP) {
680 dev->tx_fifo_depth = TXGBE_TX_FIFO_DEPTH;
681 dev->rx_fifo_depth = TXGBE_RX_FIFO_DEPTH;
687 * Try to detect the FIFO depth if not set by interface driver,
688 * the depth could be from 2 to 256 from HW spec.
690 ret = i2c_dw_acquire_lock(dev);
694 ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, ¶m);
695 i2c_dw_release_lock(dev);
699 tx_fifo_depth = ((param >> 16) & 0xff) + 1;
700 rx_fifo_depth = ((param >> 8) & 0xff) + 1;
701 if (!dev->tx_fifo_depth) {
702 dev->tx_fifo_depth = tx_fifo_depth;
703 dev->rx_fifo_depth = rx_fifo_depth;
704 } else if (tx_fifo_depth >= 2) {
705 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
707 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
714 u32 i2c_dw_func(struct i2c_adapter *adap)
716 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
718 return dev->functionality;
721 void i2c_dw_disable(struct dw_i2c_dev *dev)
726 ret = i2c_dw_acquire_lock(dev);
730 /* Disable controller */
731 __i2c_dw_disable(dev);
733 /* Disable all interrupts */
734 __i2c_dw_write_intr_mask(dev, 0);
735 regmap_read(dev->map, DW_IC_CLR_INTR, &dummy);
737 i2c_dw_release_lock(dev);
739 EXPORT_SYMBOL_GPL(i2c_dw_disable);
741 int i2c_dw_probe(struct dw_i2c_dev *dev)
743 device_set_node(&dev->adapter.dev, dev_fwnode(dev->dev));
747 return i2c_dw_probe_slave(dev);
749 return i2c_dw_probe_master(dev);
751 dev_err(dev->dev, "Wrong operation mode: %d\n", dev->mode);
755 EXPORT_SYMBOL_GPL(i2c_dw_probe);
757 static int i2c_dw_prepare(struct device *device)
760 * If the ACPI companion device object is present for this device,
761 * it may be accessed during suspend and resume of other devices via
762 * I2C operation regions, so tell the PM core and middle layers to
763 * avoid skipping system suspend/resume callbacks for it in that case.
765 return !has_acpi_companion(device);
768 static int i2c_dw_runtime_suspend(struct device *device)
770 struct dw_i2c_dev *dev = dev_get_drvdata(device);
772 if (dev->shared_with_punit)
776 i2c_dw_prepare_clk(dev, false);
781 static int i2c_dw_suspend(struct device *device)
783 struct dw_i2c_dev *dev = dev_get_drvdata(device);
785 i2c_mark_adapter_suspended(&dev->adapter);
787 return i2c_dw_runtime_suspend(device);
790 static int i2c_dw_runtime_resume(struct device *device)
792 struct dw_i2c_dev *dev = dev_get_drvdata(device);
794 if (!dev->shared_with_punit)
795 i2c_dw_prepare_clk(dev, true);
802 static int i2c_dw_resume(struct device *device)
804 struct dw_i2c_dev *dev = dev_get_drvdata(device);
806 i2c_dw_runtime_resume(device);
807 i2c_mark_adapter_resumed(&dev->adapter);
812 EXPORT_GPL_DEV_PM_OPS(i2c_dw_dev_pm_ops) = {
813 .prepare = pm_sleep_ptr(i2c_dw_prepare),
814 LATE_SYSTEM_SLEEP_PM_OPS(i2c_dw_suspend, i2c_dw_resume)
815 RUNTIME_PM_OPS(i2c_dw_runtime_suspend, i2c_dw_runtime_resume, NULL)
818 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
819 MODULE_LICENSE("GPL");