1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Microchip PCI1XXXX I2C adapter driver for PCIe Switch
4 * which has I2C controller in one of its downstream functions
5 *
6 * Copyright (C) 2021 - 2022 Microchip Technology Inc.
7 *
8 * Authors: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
9 * Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
10 */
11
12#include <linux/bits.h>
13#include <linux/delay.h>
14#include <linux/i2c.h>
15#include <linux/i2c-smbus.h>
16#include <linux/interrupt.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/pci.h>
20#include <linux/types.h>
21
22#define SMBUS_MAST_CORE_ADDR_BASE 0x00000
23#define SMBUS_MAST_SYS_REG_ADDR_BASE 0x01000
24
25/* SMB register space. */
26#define SMB_CORE_CTRL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x00)
27
28#define SMB_CORE_CTRL_ESO BIT(6)
29#define SMB_CORE_CTRL_FW_ACK BIT(4)
30#define SMB_CORE_CTRL_ACK BIT(0)
31
32#define SMB_CORE_CMD_REG_OFF3 (SMBUS_MAST_CORE_ADDR_BASE + 0x0F)
33#define SMB_CORE_CMD_REG_OFF2 (SMBUS_MAST_CORE_ADDR_BASE + 0x0E)
34#define SMB_CORE_CMD_REG_OFF1 (SMBUS_MAST_CORE_ADDR_BASE + 0x0D)
35
36#define SMB_CORE_CMD_READM BIT(4)
37#define SMB_CORE_CMD_STOP BIT(2)
38#define SMB_CORE_CMD_START BIT(0)
39
40#define SMB_CORE_CMD_REG_OFF0 (SMBUS_MAST_CORE_ADDR_BASE + 0x0C)
41
42#define SMB_CORE_CMD_M_PROCEED BIT(1)
43#define SMB_CORE_CMD_M_RUN BIT(0)
44
45#define SMB_CORE_SR_HOLD_TIME_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x18)
46
47/*
48 * SR_HOLD_TIME_XK_TICKS field will indicate the number of ticks of the
49 * baud clock required to program 'Hold Time' at X KHz.
50 */
51#define SR_HOLD_TIME_100K_TICKS 150
52#define SR_HOLD_TIME_400K_TICKS 20
53#define SR_HOLD_TIME_1000K_TICKS 12
54
55#define SMB_CORE_COMPLETION_REG_OFF3 (SMBUS_MAST_CORE_ADDR_BASE + 0x23)
56
57#define COMPLETION_MDONE BIT(6)
58#define COMPLETION_IDLE BIT(5)
59#define COMPLETION_MNAKX BIT(0)
60
61#define SMB_CORE_IDLE_SCALING_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x24)
62
63/*
64 * FAIR_BUS_IDLE_MIN_XK_TICKS field will indicate the number of ticks of
65 * the baud clock required to program 'fair idle delay' at X KHz. Fair idle
66 * delay establishes the MCTP T(IDLE_DELAY) period.
67 */
68#define FAIR_BUS_IDLE_MIN_100K_TICKS 992
69#define FAIR_BUS_IDLE_MIN_400K_TICKS 500
70#define FAIR_BUS_IDLE_MIN_1000K_TICKS 500
71
72/*
73 * FAIR_IDLE_DELAY_XK_TICKS field will indicate the number of ticks of the
74 * baud clock required to satisfy the fairness protocol at X KHz.
75 */
76#define FAIR_IDLE_DELAY_100K_TICKS 963
77#define FAIR_IDLE_DELAY_400K_TICKS 156
78#define FAIR_IDLE_DELAY_1000K_TICKS 156
79
80#define SMB_IDLE_SCALING_100K \
81 ((FAIR_IDLE_DELAY_100K_TICKS << 16) | FAIR_BUS_IDLE_MIN_100K_TICKS)
82#define SMB_IDLE_SCALING_400K \
83 ((FAIR_IDLE_DELAY_400K_TICKS << 16) | FAIR_BUS_IDLE_MIN_400K_TICKS)
84#define SMB_IDLE_SCALING_1000K \
85 ((FAIR_IDLE_DELAY_1000K_TICKS << 16) | FAIR_BUS_IDLE_MIN_1000K_TICKS)
86
87#define SMB_CORE_CONFIG_REG3 (SMBUS_MAST_CORE_ADDR_BASE + 0x2B)
88
89#define SMB_CONFIG3_ENMI BIT(6)
90#define SMB_CONFIG3_ENIDI BIT(5)
91
92#define SMB_CORE_CONFIG_REG2 (SMBUS_MAST_CORE_ADDR_BASE + 0x2A)
93#define SMB_CORE_CONFIG_REG1 (SMBUS_MAST_CORE_ADDR_BASE + 0x29)
94
95#define SMB_CONFIG1_ASR BIT(7)
96#define SMB_CONFIG1_ENAB BIT(2)
97#define SMB_CONFIG1_RESET BIT(1)
98#define SMB_CONFIG1_FEN BIT(0)
99
100#define SMB_CORE_BUS_CLK_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x2C)
101
102/*
103 * BUS_CLK_XK_LOW_PERIOD_TICKS field defines the number of I2C Baud Clock
104 * periods that make up the low phase of the I2C/SMBus bus clock at X KHz.
105 */
106#define BUS_CLK_100K_LOW_PERIOD_TICKS 156
107#define BUS_CLK_400K_LOW_PERIOD_TICKS 41
108#define BUS_CLK_1000K_LOW_PERIOD_TICKS 15
109
110/*
111 * BUS_CLK_XK_HIGH_PERIOD_TICKS field defines the number of I2C Baud Clock
112 * periods that make up the high phase of the I2C/SMBus bus clock at X KHz.
113 */
114#define BUS_CLK_100K_HIGH_PERIOD_TICKS 154
115#define BUS_CLK_400K_HIGH_PERIOD_TICKS 35
116#define BUS_CLK_1000K_HIGH_PERIOD_TICKS 14
117
118#define BUS_CLK_100K \
119 ((BUS_CLK_100K_HIGH_PERIOD_TICKS << 8) | BUS_CLK_100K_LOW_PERIOD_TICKS)
120#define BUS_CLK_400K \
121 ((BUS_CLK_400K_HIGH_PERIOD_TICKS << 8) | BUS_CLK_400K_LOW_PERIOD_TICKS)
122#define BUS_CLK_1000K \
123 ((BUS_CLK_1000K_HIGH_PERIOD_TICKS << 8) | BUS_CLK_1000K_LOW_PERIOD_TICKS)
124
125#define SMB_CORE_CLK_SYNC_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x3C)
126
127/*
128 * CLK_SYNC_XK defines the number of clock cycles to sync up to the external
129 * clock before comparing the internal and external clocks for clock stretching
130 * at X KHz.
131 */
132#define CLK_SYNC_100K 4
133#define CLK_SYNC_400K 4
134#define CLK_SYNC_1000K 4
135
136#define SMB_CORE_DATA_TIMING_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x40)
137
138/*
139 *
140 * FIRST_START_HOLD_XK_TICKS will indicate the number of ticks of the baud
141 * clock required to program 'FIRST_START_HOLD' timer at X KHz. This timer
142 * determines the SCLK hold time following SDAT driven low during the first
143 * START bit in a transfer.
144 */
145#define FIRST_START_HOLD_100K_TICKS 23
146#define FIRST_START_HOLD_400K_TICKS 8
147#define FIRST_START_HOLD_1000K_TICKS 12
148
149/*
150 * STOP_SETUP_XK_TICKS will indicate the number of ticks of the baud clock
151 * required to program 'STOP_SETUP' timer at X KHz. This timer determines the
152 * SDAT setup time from the rising edge of SCLK for a STOP condition.
153 */
154#define STOP_SETUP_100K_TICKS 150
155#define STOP_SETUP_400K_TICKS 20
156#define STOP_SETUP_1000K_TICKS 12
157
158/*
159 * RESTART_SETUP_XK_TICKS will indicate the number of ticks of the baud clock
160 * required to program 'RESTART_SETUP' timer at X KHz. This timer determines the
161 * SDAT setup time from the rising edge of SCLK for a repeated START condition.
162 */
163#define RESTART_SETUP_100K_TICKS 156
164#define RESTART_SETUP_400K_TICKS 20
165#define RESTART_SETUP_1000K_TICKS 12
166
167/*
168 * DATA_HOLD_XK_TICKS will indicate the number of ticks of the baud clock
169 * required to program 'DATA_HOLD' timer at X KHz. This timer determines the
170 * SDAT hold time following SCLK driven low.
171 */
172#define DATA_HOLD_100K_TICKS 12
173#define DATA_HOLD_400K_TICKS 2
174#define DATA_HOLD_1000K_TICKS 2
175
176#define DATA_TIMING_100K \
177 ((FIRST_START_HOLD_100K_TICKS << 24) | (STOP_SETUP_100K_TICKS << 16) | \
178 (RESTART_SETUP_100K_TICKS << 8) | DATA_HOLD_100K_TICKS)
179#define DATA_TIMING_400K \
180 ((FIRST_START_HOLD_400K_TICKS << 24) | (STOP_SETUP_400K_TICKS << 16) | \
181 (RESTART_SETUP_400K_TICKS << 8) | DATA_HOLD_400K_TICKS)
182#define DATA_TIMING_1000K \
183 ((FIRST_START_HOLD_1000K_TICKS << 24) | (STOP_SETUP_1000K_TICKS << 16) | \
184 (RESTART_SETUP_1000K_TICKS << 8) | DATA_HOLD_1000K_TICKS)
185
186#define SMB_CORE_TO_SCALING_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x44)
187
188/*
189 * BUS_IDLE_MIN_XK_TICKS defines Bus Idle Minimum Time.
190 * Bus Idle Minimum time = BUS_IDLE_MIN[7:0] x Baud_Clock_Period x
191 * (BUS_IDLE_MIN_XK_TICKS[7] ? 4,1)
192 */
193#define BUS_IDLE_MIN_100K_TICKS 36UL
194#define BUS_IDLE_MIN_400K_TICKS 10UL
195#define BUS_IDLE_MIN_1000K_TICKS 4UL
196
197/*
198 * CTRL_CUM_TIME_OUT_XK_TICKS defines SMBus Controller Cumulative Time-Out.
199 * SMBus Controller Cumulative Time-Out duration =
200 * CTRL_CUM_TIME_OUT_XK_TICKS[7:0] x Baud_Clock_Period x 2048
201 */
202#define CTRL_CUM_TIME_OUT_100K_TICKS 76
203#define CTRL_CUM_TIME_OUT_400K_TICKS 76
204#define CTRL_CUM_TIME_OUT_1000K_TICKS 76
205
206/*
207 * TARGET_CUM_TIME_OUT_XK_TICKS defines SMBus Target Cumulative Time-Out duration.
208 * SMBus Target Cumulative Time-Out duration = TARGET_CUM_TIME_OUT_XK_TICKS[7:0] x
209 * Baud_Clock_Period x 4096
210 */
211#define TARGET_CUM_TIME_OUT_100K_TICKS 95
212#define TARGET_CUM_TIME_OUT_400K_TICKS 95
213#define TARGET_CUM_TIME_OUT_1000K_TICKS 95
214
215/*
216 * CLOCK_HIGH_TIME_OUT_XK defines Clock High time out period.
217 * Clock High time out period = CLOCK_HIGH_TIME_OUT_XK[7:0] x Baud_Clock_Period x 8
218 */
219#define CLOCK_HIGH_TIME_OUT_100K_TICKS 97
220#define CLOCK_HIGH_TIME_OUT_400K_TICKS 97
221#define CLOCK_HIGH_TIME_OUT_1000K_TICKS 97
222
223#define TO_SCALING_100K \
224 ((BUS_IDLE_MIN_100K_TICKS << 24) | (CTRL_CUM_TIME_OUT_100K_TICKS << 16) | \
225 (TARGET_CUM_TIME_OUT_100K_TICKS << 8) | CLOCK_HIGH_TIME_OUT_100K_TICKS)
226#define TO_SCALING_400K \
227 ((BUS_IDLE_MIN_400K_TICKS << 24) | (CTRL_CUM_TIME_OUT_400K_TICKS << 16) | \
228 (TARGET_CUM_TIME_OUT_400K_TICKS << 8) | CLOCK_HIGH_TIME_OUT_400K_TICKS)
229#define TO_SCALING_1000K \
230 ((BUS_IDLE_MIN_1000K_TICKS << 24) | (CTRL_CUM_TIME_OUT_1000K_TICKS << 16) | \
231 (TARGET_CUM_TIME_OUT_1000K_TICKS << 8) | CLOCK_HIGH_TIME_OUT_1000K_TICKS)
232
233#define I2C_SCL_PAD_CTRL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x100)
234#define I2C_SDA_PAD_CTRL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x101)
235
236#define I2C_FOD_EN BIT(4)
237#define I2C_PULL_UP_EN BIT(3)
238#define I2C_PULL_DOWN_EN BIT(2)
239#define I2C_INPUT_EN BIT(1)
240#define I2C_OUTPUT_EN BIT(0)
241
242#define SMBUS_CONTROL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x200)
243
244#define CTL_RESET_COUNTERS BIT(3)
245#define CTL_TRANSFER_DIR BIT(2)
246#define CTL_HOST_FIFO_ENTRY BIT(1)
247#define CTL_RUN BIT(0)
248
249#define I2C_DIRN_WRITE 0
250#define I2C_DIRN_READ 1
251
252#define SMBUS_STATUS_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x204)
253
254#define STA_DMA_TERM BIT(7)
255#define STA_DMA_REQ BIT(6)
256#define STA_THRESHOLD BIT(2)
257#define STA_BUF_FULL BIT(1)
258#define STA_BUF_EMPTY BIT(0)
259
260#define SMBUS_INTR_STAT_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x208)
261
262#define INTR_STAT_DMA_TERM BIT(7)
263#define INTR_STAT_THRESHOLD BIT(2)
264#define INTR_STAT_BUF_FULL BIT(1)
265#define INTR_STAT_BUF_EMPTY BIT(0)
266
267#define SMBUS_INTR_MSK_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x20C)
268
269#define INTR_MSK_DMA_TERM BIT(7)
270#define INTR_MSK_THRESHOLD BIT(2)
271#define INTR_MSK_BUF_FULL BIT(1)
272#define INTR_MSK_BUF_EMPTY BIT(0)
273
274#define ALL_NW_LAYER_INTERRUPTS \
275 (INTR_MSK_DMA_TERM | INTR_MSK_THRESHOLD | INTR_MSK_BUF_FULL | \
276 INTR_MSK_BUF_EMPTY)
277
278#define SMBUS_MCU_COUNTER_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x214)
279
280#define SMBALERT_MST_PAD_CTRL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x230)
281
282#define SMBALERT_MST_PU BIT(0)
283
284#define SMBUS_GEN_INT_STAT_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x23C)
285
286#define SMBUS_GEN_INT_MASK_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x240)
287
288#define SMBALERT_INTR_MASK BIT(10)
289#define I2C_BUF_MSTR_INTR_MASK BIT(9)
290#define I2C_INTR_MASK BIT(8)
291#define SMBALERT_WAKE_INTR_MASK BIT(2)
292#define I2C_BUF_MSTR_WAKE_INTR_MASK BIT(1)
293#define I2C_WAKE_INTR_MASK BIT(0)
294
295#define ALL_HIGH_LAYER_INTR \
296 (SMBALERT_INTR_MASK | I2C_BUF_MSTR_INTR_MASK | I2C_INTR_MASK | \
297 SMBALERT_WAKE_INTR_MASK | I2C_BUF_MSTR_WAKE_INTR_MASK | \
298 I2C_WAKE_INTR_MASK)
299
300#define SMBUS_RESET_REG (SMBUS_MAST_CORE_ADDR_BASE + 0x248)
301
302#define PERI_SMBUS_D3_RESET_DIS BIT(16)
303
304#define SMBUS_MST_BUF (SMBUS_MAST_CORE_ADDR_BASE + 0x280)
305
306#define SMBUS_BUF_MAX_SIZE 0x80
307
308#define I2C_FLAGS_DIRECT_MODE BIT(7)
309#define I2C_FLAGS_POLLING_MODE BIT(6)
310#define I2C_FLAGS_STOP BIT(5)
311#define I2C_FLAGS_SMB_BLK_READ BIT(4)
312
313#define PCI1XXXX_I2C_TIMEOUT_MS 1000
314
315/* General Purpose Register. */
316#define SMB_GPR_REG (SMBUS_MAST_CORE_ADDR_BASE + 0x1000 + 0x0c00 + \
317 0x00)
318
319/* Lock Register. */
320#define SMB_GPR_LOCK_REG (SMBUS_MAST_CORE_ADDR_BASE + 0x1000 + 0x0000 + \
321 0x00A0)
322
323#define SMBUS_PERI_LOCK BIT(3)
324
325struct pci1xxxx_i2c {
326 struct completion i2c_xfer_done;
327 bool i2c_xfer_in_progress;
328 struct i2c_adapter adap;
329 void __iomem *i2c_base;
330 u32 freq;
331 u32 flags;
332};
333
334static int set_sys_lock(struct pci1xxxx_i2c *i2c)
335{
336 void __iomem *p = i2c->i2c_base + SMB_GPR_LOCK_REG;
337 u8 data;
338
339 writel(SMBUS_PERI_LOCK, addr: p);
340 data = readl(addr: p);
341 if (data != SMBUS_PERI_LOCK)
342 return -EPERM;
343
344 return 0;
345}
346
347static int release_sys_lock(struct pci1xxxx_i2c *i2c)
348{
349 void __iomem *p = i2c->i2c_base + SMB_GPR_LOCK_REG;
350 u8 data;
351
352 data = readl(addr: p);
353 if (data != SMBUS_PERI_LOCK)
354 return 0;
355
356 writel(val: 0, addr: p);
357 data = readl(addr: p);
358 if (data & SMBUS_PERI_LOCK)
359 return -EPERM;
360
361 return 0;
362}
363
364static void pci1xxxx_ack_high_level_intr(struct pci1xxxx_i2c *i2c, u16 intr_msk)
365{
366 writew(val: intr_msk, addr: i2c->i2c_base + SMBUS_GEN_INT_STAT_REG_OFF);
367}
368
369static void pci1xxxx_i2c_configure_smbalert_pin(struct pci1xxxx_i2c *i2c,
370 bool enable)
371{
372 void __iomem *p = i2c->i2c_base + SMBALERT_MST_PAD_CTRL_REG_OFF;
373 u8 regval;
374
375 regval = readb(addr: p);
376
377 if (enable)
378 regval |= SMBALERT_MST_PU;
379 else
380 regval &= ~SMBALERT_MST_PU;
381
382 writeb(val: regval, addr: p);
383}
384
385static void pci1xxxx_i2c_send_start_stop(struct pci1xxxx_i2c *i2c, bool start)
386{
387 void __iomem *p = i2c->i2c_base + SMB_CORE_CMD_REG_OFF1;
388 u8 regval;
389
390 regval = readb(addr: p);
391
392 if (start)
393 regval |= SMB_CORE_CMD_START;
394 else
395 regval |= SMB_CORE_CMD_STOP;
396
397 writeb(val: regval, addr: p);
398}
399
400/*
401 * When accessing the core control reg, we should not do a read modified write
402 * as they are write '1' to clear bits. Instead we need to write with the
403 * specific bits that needs to be set.
404 */
405static void pci1xxxx_i2c_set_clear_FW_ACK(struct pci1xxxx_i2c *i2c, bool set)
406{
407 u8 regval;
408
409 if (set)
410 regval = SMB_CORE_CTRL_FW_ACK | SMB_CORE_CTRL_ESO | SMB_CORE_CTRL_ACK;
411 else
412 regval = SMB_CORE_CTRL_ESO | SMB_CORE_CTRL_ACK;
413
414 writeb(val: regval, addr: i2c->i2c_base + SMB_CORE_CTRL_REG_OFF);
415}
416
417static void pci1xxxx_i2c_buffer_write(struct pci1xxxx_i2c *i2c, u8 slaveaddr,
418 u8 transferlen, unsigned char *buf)
419{
420 void __iomem *p = i2c->i2c_base + SMBUS_MST_BUF;
421
422 if (slaveaddr)
423 writeb(val: slaveaddr, addr: p++);
424
425 if (buf)
426 memcpy_toio(p, buf, transferlen);
427}
428
429/*
430 * When accessing the core control reg, we should not do a read modified write
431 * as there are write '1' to clear bits. Instead we need to write with the
432 * specific bits that needs to be set.
433 */
434static void pci1xxxx_i2c_enable_ESO(struct pci1xxxx_i2c *i2c)
435{
436 writeb(SMB_CORE_CTRL_ESO, addr: i2c->i2c_base + SMB_CORE_CTRL_REG_OFF);
437}
438
439static void pci1xxxx_i2c_reset_counters(struct pci1xxxx_i2c *i2c)
440{
441 void __iomem *p = i2c->i2c_base + SMBUS_CONTROL_REG_OFF;
442 u8 regval;
443
444 regval = readb(addr: p);
445 regval |= CTL_RESET_COUNTERS;
446 writeb(val: regval, addr: p);
447}
448
449static void pci1xxxx_i2c_set_transfer_dir(struct pci1xxxx_i2c *i2c, u8 direction)
450{
451 void __iomem *p = i2c->i2c_base + SMBUS_CONTROL_REG_OFF;
452 u8 regval;
453
454 regval = readb(addr: p);
455 if (direction == I2C_DIRN_WRITE)
456 regval &= ~CTL_TRANSFER_DIR;
457 else
458 regval |= CTL_TRANSFER_DIR;
459
460 writeb(val: regval, addr: p);
461}
462
463static void pci1xxxx_i2c_set_mcu_count(struct pci1xxxx_i2c *i2c, u8 count)
464{
465 writeb(val: count, addr: i2c->i2c_base + SMBUS_MCU_COUNTER_REG_OFF);
466}
467
468static void pci1xxxx_i2c_set_read_count(struct pci1xxxx_i2c *i2c, u8 readcount)
469{
470 writeb(val: readcount, addr: i2c->i2c_base + SMB_CORE_CMD_REG_OFF3);
471}
472
473static void pci1xxxx_i2c_set_write_count(struct pci1xxxx_i2c *i2c, u8 writecount)
474{
475 writeb(val: writecount, addr: i2c->i2c_base + SMB_CORE_CMD_REG_OFF2);
476}
477
478static void pci1xxxx_i2c_set_DMA_run(struct pci1xxxx_i2c *i2c)
479{
480 void __iomem *p = i2c->i2c_base + SMBUS_CONTROL_REG_OFF;
481 u8 regval;
482
483 regval = readb(addr: p);
484 regval |= CTL_RUN;
485 writeb(val: regval, addr: p);
486}
487
488static void pci1xxxx_i2c_set_mrun_proceed(struct pci1xxxx_i2c *i2c)
489{
490 void __iomem *p = i2c->i2c_base + SMB_CORE_CMD_REG_OFF0;
491 u8 regval;
492
493 regval = readb(addr: p);
494 regval |= SMB_CORE_CMD_M_RUN;
495 regval |= SMB_CORE_CMD_M_PROCEED;
496 writeb(val: regval, addr: p);
497}
498
499static void pci1xxxx_i2c_start_DMA(struct pci1xxxx_i2c *i2c)
500{
501 pci1xxxx_i2c_set_DMA_run(i2c);
502 pci1xxxx_i2c_set_mrun_proceed(i2c);
503}
504
505static void pci1xxxx_i2c_config_asr(struct pci1xxxx_i2c *i2c, bool enable)
506{
507 void __iomem *p = i2c->i2c_base + SMB_CORE_CONFIG_REG1;
508 u8 regval;
509
510 regval = readb(addr: p);
511 if (enable)
512 regval |= SMB_CONFIG1_ASR;
513 else
514 regval &= ~SMB_CONFIG1_ASR;
515 writeb(val: regval, addr: p);
516}
517
518static irqreturn_t pci1xxxx_i2c_isr(int irq, void *dev)
519{
520 struct pci1xxxx_i2c *i2c = dev;
521 void __iomem *p1 = i2c->i2c_base + SMBUS_GEN_INT_STAT_REG_OFF;
522 void __iomem *p2 = i2c->i2c_base + SMBUS_INTR_STAT_REG_OFF;
523 irqreturn_t intr_handled = IRQ_NONE;
524 u16 reg1;
525 u8 reg3;
526
527 /*
528 * Read the SMBus interrupt status register to see if the
529 * DMA_TERM interrupt has caused this callback.
530 */
531 reg1 = readw(addr: p1);
532
533 if (reg1 & I2C_BUF_MSTR_INTR_MASK) {
534 reg3 = readb(addr: p2);
535 if (reg3 & INTR_STAT_DMA_TERM) {
536 complete(&i2c->i2c_xfer_done);
537 intr_handled = IRQ_HANDLED;
538 writeb(INTR_STAT_DMA_TERM, addr: p2);
539 }
540 pci1xxxx_ack_high_level_intr(i2c, I2C_BUF_MSTR_INTR_MASK);
541 }
542
543 if (reg1 & SMBALERT_INTR_MASK) {
544 intr_handled = IRQ_HANDLED;
545 pci1xxxx_ack_high_level_intr(i2c, SMBALERT_INTR_MASK);
546 }
547
548 return intr_handled;
549}
550
551static void pci1xxxx_i2c_set_count(struct pci1xxxx_i2c *i2c, u8 mcucount,
552 u8 writecount, u8 readcount)
553{
554 pci1xxxx_i2c_set_mcu_count(i2c, count: mcucount);
555 pci1xxxx_i2c_set_write_count(i2c, writecount);
556 pci1xxxx_i2c_set_read_count(i2c, readcount);
557}
558
559static void pci1xxxx_i2c_set_readm(struct pci1xxxx_i2c *i2c, bool enable)
560{
561 void __iomem *p = i2c->i2c_base + SMB_CORE_CMD_REG_OFF1;
562 u8 regval;
563
564 regval = readb(addr: p);
565 if (enable)
566 regval |= SMB_CORE_CMD_READM;
567 else
568 regval &= ~SMB_CORE_CMD_READM;
569
570 writeb(val: regval, addr: p);
571}
572
573static void pci1xxxx_ack_nw_layer_intr(struct pci1xxxx_i2c *i2c, u8 ack_intr_msk)
574{
575 writeb(val: ack_intr_msk, addr: i2c->i2c_base + SMBUS_INTR_STAT_REG_OFF);
576}
577
578static void pci1xxxx_config_nw_layer_intr(struct pci1xxxx_i2c *i2c,
579 u8 intr_msk, bool enable)
580{
581 void __iomem *p = i2c->i2c_base + SMBUS_INTR_MSK_REG_OFF;
582 u8 regval;
583
584 regval = readb(addr: p);
585 if (enable)
586 regval &= ~intr_msk;
587 else
588 regval |= intr_msk;
589
590 writeb(val: regval, addr: p);
591}
592
593static void pci1xxxx_i2c_config_padctrl(struct pci1xxxx_i2c *i2c, bool enable)
594{
595 void __iomem *p1 = i2c->i2c_base + I2C_SCL_PAD_CTRL_REG_OFF;
596 void __iomem *p2 = i2c->i2c_base + I2C_SDA_PAD_CTRL_REG_OFF;
597 u8 regval;
598
599 regval = readb(addr: p1);
600 if (enable)
601 regval |= I2C_INPUT_EN | I2C_OUTPUT_EN;
602 else
603 regval &= ~(I2C_INPUT_EN | I2C_OUTPUT_EN);
604
605 writeb(val: regval, addr: p1);
606
607 regval = readb(addr: p2);
608 if (enable)
609 regval |= I2C_INPUT_EN | I2C_OUTPUT_EN;
610 else
611 regval &= ~(I2C_INPUT_EN | I2C_OUTPUT_EN);
612
613 writeb(val: regval, addr: p2);
614}
615
616static void pci1xxxx_i2c_set_mode(struct pci1xxxx_i2c *i2c)
617{
618 void __iomem *p = i2c->i2c_base + SMBUS_CONTROL_REG_OFF;
619 u8 regval;
620
621 regval = readb(addr: p);
622 if (i2c->flags & I2C_FLAGS_DIRECT_MODE)
623 regval &= ~CTL_HOST_FIFO_ENTRY;
624 else
625 regval |= CTL_HOST_FIFO_ENTRY;
626
627 writeb(val: regval, addr: p);
628}
629
630static void pci1xxxx_i2c_config_high_level_intr(struct pci1xxxx_i2c *i2c,
631 u16 intr_msk, bool enable)
632{
633 void __iomem *p = i2c->i2c_base + SMBUS_GEN_INT_MASK_REG_OFF;
634 u16 regval;
635
636 regval = readw(addr: p);
637 if (enable)
638 regval &= ~intr_msk;
639 else
640 regval |= intr_msk;
641 writew(val: regval, addr: p);
642}
643
644static void pci1xxxx_i2c_configure_core_reg(struct pci1xxxx_i2c *i2c, bool enable)
645{
646 void __iomem *p1 = i2c->i2c_base + SMB_CORE_CONFIG_REG1;
647 void __iomem *p3 = i2c->i2c_base + SMB_CORE_CONFIG_REG3;
648 u8 reg1;
649 u8 reg3;
650
651 reg1 = readb(addr: p1);
652 reg3 = readb(addr: p3);
653 if (enable) {
654 reg1 |= SMB_CONFIG1_ENAB | SMB_CONFIG1_FEN;
655 reg3 |= SMB_CONFIG3_ENMI | SMB_CONFIG3_ENIDI;
656 } else {
657 reg1 &= ~(SMB_CONFIG1_ENAB | SMB_CONFIG1_FEN);
658 reg3 &= ~(SMB_CONFIG3_ENMI | SMB_CONFIG3_ENIDI);
659 }
660
661 writeb(val: reg1, addr: p1);
662 writeb(val: reg3, addr: p3);
663}
664
665static void pci1xxxx_i2c_set_freq(struct pci1xxxx_i2c *i2c)
666{
667 void __iomem *bp = i2c->i2c_base;
668 void __iomem *p_idle_scaling = bp + SMB_CORE_IDLE_SCALING_REG_OFF;
669 void __iomem *p_data_timing = bp + SMB_CORE_DATA_TIMING_REG_OFF;
670 void __iomem *p_hold_time = bp + SMB_CORE_SR_HOLD_TIME_REG_OFF;
671 void __iomem *p_to_scaling = bp + SMB_CORE_TO_SCALING_REG_OFF;
672 void __iomem *p_clk_sync = bp + SMB_CORE_CLK_SYNC_REG_OFF;
673 void __iomem *p_clk_reg = bp + SMB_CORE_BUS_CLK_REG_OFF;
674
675 switch (i2c->freq) {
676 case I2C_MAX_STANDARD_MODE_FREQ:
677 writeb(SR_HOLD_TIME_100K_TICKS, addr: p_hold_time);
678 writel(SMB_IDLE_SCALING_100K, addr: p_idle_scaling);
679 writew(BUS_CLK_100K, addr: p_clk_reg);
680 writel(CLK_SYNC_100K, addr: p_clk_sync);
681 writel(DATA_TIMING_100K, addr: p_data_timing);
682 writel(TO_SCALING_100K, addr: p_to_scaling);
683 break;
684
685 case I2C_MAX_FAST_MODE_PLUS_FREQ:
686 writeb(SR_HOLD_TIME_1000K_TICKS, addr: p_hold_time);
687 writel(SMB_IDLE_SCALING_1000K, addr: p_idle_scaling);
688 writew(BUS_CLK_1000K, addr: p_clk_reg);
689 writel(CLK_SYNC_1000K, addr: p_clk_sync);
690 writel(DATA_TIMING_1000K, addr: p_data_timing);
691 writel(TO_SCALING_1000K, addr: p_to_scaling);
692 break;
693
694 case I2C_MAX_FAST_MODE_FREQ:
695 default:
696 writeb(SR_HOLD_TIME_400K_TICKS, addr: p_hold_time);
697 writel(SMB_IDLE_SCALING_400K, addr: p_idle_scaling);
698 writew(BUS_CLK_400K, addr: p_clk_reg);
699 writel(CLK_SYNC_400K, addr: p_clk_sync);
700 writel(DATA_TIMING_400K, addr: p_data_timing);
701 writel(TO_SCALING_400K, addr: p_to_scaling);
702 break;
703 }
704}
705
706static void pci1xxxx_i2c_init(struct pci1xxxx_i2c *i2c)
707{
708 void __iomem *p2 = i2c->i2c_base + SMBUS_STATUS_REG_OFF;
709 void __iomem *p1 = i2c->i2c_base + SMB_GPR_REG;
710 u8 regval;
711 int ret;
712
713 ret = set_sys_lock(i2c);
714 if (ret == -EPERM) {
715 /*
716 * Configure I2C Fast Mode as default frequency if unable
717 * to acquire sys lock.
718 */
719 regval = 0;
720 } else {
721 regval = readl(addr: p1);
722 release_sys_lock(i2c);
723 }
724
725 switch (regval) {
726 case 0:
727 i2c->freq = I2C_MAX_FAST_MODE_FREQ;
728 pci1xxxx_i2c_set_freq(i2c);
729 break;
730 case 1:
731 i2c->freq = I2C_MAX_STANDARD_MODE_FREQ;
732 pci1xxxx_i2c_set_freq(i2c);
733 break;
734 case 2:
735 i2c->freq = I2C_MAX_FAST_MODE_PLUS_FREQ;
736 pci1xxxx_i2c_set_freq(i2c);
737 break;
738 case 3:
739 default:
740 break;
741 }
742
743 pci1xxxx_i2c_config_padctrl(i2c, enable: true);
744 i2c->flags |= I2C_FLAGS_DIRECT_MODE;
745 pci1xxxx_i2c_set_mode(i2c);
746
747 /*
748 * Added as a precaution since BUF_EMPTY in status register
749 * also trigered an Interrupt.
750 */
751 writeb(STA_BUF_EMPTY, addr: p2);
752
753 /* Configure core I2c control registers. */
754 pci1xxxx_i2c_configure_core_reg(i2c, enable: true);
755
756 /*
757 * Enable pull-up for the SMB alert pin which is just used for
758 * wakeup right now.
759 */
760 pci1xxxx_i2c_configure_smbalert_pin(i2c, enable: true);
761}
762
763static void pci1xxxx_i2c_clear_flags(struct pci1xxxx_i2c *i2c)
764{
765 u8 regval;
766
767 /* Reset the internal buffer counters. */
768 pci1xxxx_i2c_reset_counters(i2c);
769
770 /* Clear low level interrupts. */
771 regval = COMPLETION_MNAKX | COMPLETION_IDLE | COMPLETION_MDONE;
772 writeb(val: regval, addr: i2c->i2c_base + SMB_CORE_COMPLETION_REG_OFF3);
773 reinit_completion(x: &i2c->i2c_xfer_done);
774 pci1xxxx_ack_nw_layer_intr(i2c, ALL_NW_LAYER_INTERRUPTS);
775 pci1xxxx_ack_high_level_intr(i2c, ALL_HIGH_LAYER_INTR);
776}
777
778static int pci1xxxx_i2c_read(struct pci1xxxx_i2c *i2c, u8 slaveaddr,
779 unsigned char *buf, u16 total_len)
780{
781 void __iomem *p2 = i2c->i2c_base + SMB_CORE_COMPLETION_REG_OFF3;
782 void __iomem *p1 = i2c->i2c_base + SMB_CORE_CMD_REG_OFF1;
783 void __iomem *p3 = i2c->i2c_base + SMBUS_MST_BUF;
784 unsigned long time_left;
785 u16 remainingbytes;
786 u8 transferlen;
787 int retval = 0;
788 u8 read_count;
789 u32 regval;
790 u16 count;
791
792 /* Enable I2C host controller by setting the ESO bit in the CONTROL REG. */
793 pci1xxxx_i2c_enable_ESO(i2c);
794 pci1xxxx_i2c_clear_flags(i2c);
795 pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, enable: true);
796 pci1xxxx_i2c_config_high_level_intr(i2c, I2C_BUF_MSTR_INTR_MASK, enable: true);
797
798 /*
799 * The I2C transfer could be more than 128 bytes. Our Core is
800 * capable of only sending 128 at a time.
801 * As far as the I2C read is concerned, initailly send the
802 * read slave address along with the number of bytes to read in
803 * ReadCount. After sending the slave address the interrupt
804 * is generated. On seeing the ACK for the slave address, reverse the
805 * buffer direction and run the DMA to initiate Read from slave.
806 */
807 for (count = 0; count < total_len; count += transferlen) {
808
809 /*
810 * Before start of any transaction clear the existing
811 * START/STOP conditions.
812 */
813 writeb(val: 0, addr: p1);
814 remainingbytes = total_len - count;
815 transferlen = min_t(u16, remainingbytes, SMBUS_BUF_MAX_SIZE);
816
817 /*
818 * Send STOP bit for the last chunk in the transaction.
819 * For I2C read transaction of more than BUF_SIZE, NACK should
820 * only be sent for the last read.
821 * Hence a bit FW_ACK is set for all the read chunks except for
822 * the last chunk. For the last chunk NACK should be sent and
823 * FW_ACK is cleared Send STOP only when I2C_FLAGS_STOP bit is
824 * set in the flags and only for the last transaction.
825 */
826 if ((count + transferlen >= total_len) &&
827 (i2c->flags & I2C_FLAGS_STOP)) {
828 pci1xxxx_i2c_set_clear_FW_ACK(i2c, set: false);
829 pci1xxxx_i2c_send_start_stop(i2c, start: 0);
830 } else {
831 pci1xxxx_i2c_set_clear_FW_ACK(i2c, set: true);
832 }
833
834 /* Send START bit for the first transaction. */
835 if (count == 0) {
836 pci1xxxx_i2c_set_transfer_dir(i2c, I2C_DIRN_WRITE);
837 pci1xxxx_i2c_send_start_stop(i2c, start: 1);
838
839 /* Write I2c buffer with just the slave addr. */
840 pci1xxxx_i2c_buffer_write(i2c, slaveaddr, transferlen: 0, NULL);
841
842 /* Set the count. Readcount is the transfer bytes. */
843 pci1xxxx_i2c_set_count(i2c, mcucount: 1, writecount: 1, readcount: transferlen);
844
845 /*
846 * Set the Auto_start_read bit so that the HW itself
847 * will take care of the read phase.
848 */
849 pci1xxxx_i2c_config_asr(i2c, enable: true);
850 if (i2c->flags & I2C_FLAGS_SMB_BLK_READ)
851 pci1xxxx_i2c_set_readm(i2c, enable: true);
852 } else {
853 pci1xxxx_i2c_set_count(i2c, mcucount: 0, writecount: 0, readcount: transferlen);
854 pci1xxxx_i2c_config_asr(i2c, enable: false);
855 pci1xxxx_i2c_clear_flags(i2c);
856 pci1xxxx_i2c_set_transfer_dir(i2c, I2C_DIRN_READ);
857 }
858
859 /* Start the DMA. */
860 pci1xxxx_i2c_start_DMA(i2c);
861
862 /* Wait for the DMA_TERM interrupt. */
863 time_left = wait_for_completion_timeout(x: &i2c->i2c_xfer_done,
864 timeout: msecs_to_jiffies(PCI1XXXX_I2C_TIMEOUT_MS));
865 if (time_left == 0) {
866 /* Reset the I2C core to release the bus lock. */
867 pci1xxxx_i2c_init(i2c);
868 retval = -ETIMEDOUT;
869 goto cleanup;
870 }
871
872 /* Read the completion reg to know the reason for DMA_TERM. */
873 regval = readb(addr: p2);
874
875 /* Slave did not respond. */
876 if (regval & COMPLETION_MNAKX) {
877 writeb(COMPLETION_MNAKX, addr: p2);
878 retval = -ETIMEDOUT;
879 goto cleanup;
880 }
881
882 if (i2c->flags & I2C_FLAGS_SMB_BLK_READ) {
883 buf[0] = readb(addr: p3);
884 read_count = buf[0];
885 memcpy_fromio(&buf[1], p3 + 1, read_count);
886 } else {
887 memcpy_fromio(&buf[count], p3, transferlen);
888 }
889 }
890
891cleanup:
892 /* Disable all the interrupts. */
893 pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, enable: false);
894 pci1xxxx_i2c_config_high_level_intr(i2c, I2C_BUF_MSTR_INTR_MASK, enable: false);
895 pci1xxxx_i2c_config_asr(i2c, enable: false);
896 return retval;
897}
898
899static int pci1xxxx_i2c_write(struct pci1xxxx_i2c *i2c, u8 slaveaddr,
900 unsigned char *buf, u16 total_len)
901{
902 void __iomem *p2 = i2c->i2c_base + SMB_CORE_COMPLETION_REG_OFF3;
903 void __iomem *p1 = i2c->i2c_base + SMB_CORE_CMD_REG_OFF1;
904 unsigned long time_left;
905 u16 remainingbytes;
906 u8 actualwritelen;
907 u8 transferlen;
908 int retval = 0;
909 u32 regval;
910 u16 count;
911
912 /* Enable I2C host controller by setting the ESO bit in the CONTROL REG. */
913 pci1xxxx_i2c_enable_ESO(i2c);
914
915 /* Set the Buffer direction. */
916 pci1xxxx_i2c_set_transfer_dir(i2c, I2C_DIRN_WRITE);
917 pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, enable: true);
918 pci1xxxx_i2c_config_high_level_intr(i2c, I2C_BUF_MSTR_INTR_MASK, enable: true);
919
920 /*
921 * The i2c transfer could be more than 128 bytes. Our Core is
922 * capable of only sending 128 at a time.
923 */
924 for (count = 0; count < total_len; count += transferlen) {
925 /*
926 * Before start of any transaction clear the existing
927 * START/STOP conditions.
928 */
929 writeb(val: 0, addr: p1);
930 pci1xxxx_i2c_clear_flags(i2c);
931 remainingbytes = total_len - count;
932
933 /* If it is the starting of the transaction send START. */
934 if (count == 0) {
935 pci1xxxx_i2c_send_start_stop(i2c, start: 1);
936
937 /* -1 for the slave address. */
938 transferlen = min_t(u16, SMBUS_BUF_MAX_SIZE - 1,
939 remainingbytes);
940 pci1xxxx_i2c_buffer_write(i2c, slaveaddr,
941 transferlen, buf: &buf[count]);
942 /*
943 * The actual number of bytes written on the I2C bus
944 * is including the slave address.
945 */
946 actualwritelen = transferlen + 1;
947 } else {
948 transferlen = min_t(u16, SMBUS_BUF_MAX_SIZE, remainingbytes);
949 pci1xxxx_i2c_buffer_write(i2c, slaveaddr: 0, transferlen, buf: &buf[count]);
950 actualwritelen = transferlen;
951 }
952
953 pci1xxxx_i2c_set_count(i2c, mcucount: actualwritelen, writecount: actualwritelen, readcount: 0);
954
955 /*
956 * Send STOP only when I2C_FLAGS_STOP bit is set in the flags and
957 * only for the last transaction.
958 */
959 if (remainingbytes <= transferlen &&
960 (i2c->flags & I2C_FLAGS_STOP))
961 pci1xxxx_i2c_send_start_stop(i2c, start: 0);
962
963 pci1xxxx_i2c_start_DMA(i2c);
964
965 /*
966 * Wait for the DMA_TERM interrupt.
967 */
968 time_left = wait_for_completion_timeout(x: &i2c->i2c_xfer_done,
969 timeout: msecs_to_jiffies(PCI1XXXX_I2C_TIMEOUT_MS));
970 if (time_left == 0) {
971 /* Reset the I2C core to release the bus lock. */
972 pci1xxxx_i2c_init(i2c);
973 retval = -ETIMEDOUT;
974 goto cleanup;
975 }
976
977 regval = readb(addr: p2);
978 if (regval & COMPLETION_MNAKX) {
979 writeb(COMPLETION_MNAKX, addr: p2);
980 retval = -ETIMEDOUT;
981 goto cleanup;
982 }
983 }
984cleanup:
985 /* Disable all the interrupts. */
986 pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, enable: false);
987 pci1xxxx_i2c_config_high_level_intr(i2c, I2C_BUF_MSTR_INTR_MASK, enable: false);
988
989 return retval;
990}
991
992static int pci1xxxx_i2c_xfer(struct i2c_adapter *adap,
993 struct i2c_msg *msgs, int num)
994{
995 struct pci1xxxx_i2c *i2c = i2c_get_adapdata(adap);
996 u8 slaveaddr;
997 int retval;
998 u32 i;
999
1000 i2c->i2c_xfer_in_progress = true;
1001 for (i = 0; i < num; i++) {
1002 slaveaddr = i2c_8bit_addr_from_msg(msg: &msgs[i]);
1003
1004 /*
1005 * Send the STOP bit if the transfer is the final one or
1006 * if the I2C_M_STOP flag is set.
1007 */
1008 if ((i == num - 1) || (msgs[i].flags & I2C_M_STOP))
1009 i2c->flags |= I2C_FLAGS_STOP;
1010 else
1011 i2c->flags &= ~I2C_FLAGS_STOP;
1012
1013 if (msgs[i].flags & I2C_M_RECV_LEN)
1014 i2c->flags |= I2C_FLAGS_SMB_BLK_READ;
1015 else
1016 i2c->flags &= ~I2C_FLAGS_SMB_BLK_READ;
1017
1018 if (msgs[i].flags & I2C_M_RD)
1019 retval = pci1xxxx_i2c_read(i2c, slaveaddr,
1020 buf: msgs[i].buf, total_len: msgs[i].len);
1021 else
1022 retval = pci1xxxx_i2c_write(i2c, slaveaddr,
1023 buf: msgs[i].buf, total_len: msgs[i].len);
1024
1025 if (retval < 0)
1026 break;
1027 }
1028 i2c->i2c_xfer_in_progress = false;
1029
1030 if (retval < 0)
1031 return retval;
1032
1033 return num;
1034}
1035
1036/*
1037 * List of supported functions by the driver.
1038 */
1039static u32 pci1xxxx_i2c_get_funcs(struct i2c_adapter *adap)
1040{
1041 return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING |
1042 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
1043 I2C_FUNC_SMBUS_BYTE |
1044 I2C_FUNC_SMBUS_BYTE_DATA |
1045 I2C_FUNC_SMBUS_WORD_DATA |
1046 I2C_FUNC_SMBUS_PROC_CALL |
1047 I2C_FUNC_SMBUS_BLOCK_DATA;
1048}
1049
1050static const struct i2c_algorithm pci1xxxx_i2c_algo = {
1051 .master_xfer = pci1xxxx_i2c_xfer,
1052 .functionality = pci1xxxx_i2c_get_funcs,
1053};
1054
1055static const struct i2c_adapter_quirks pci1xxxx_i2c_quirks = {
1056 .flags = I2C_AQ_NO_ZERO_LEN,
1057};
1058
1059static const struct i2c_adapter pci1xxxx_i2c_ops = {
1060 .owner = THIS_MODULE,
1061 .name = "PCI1xxxx I2C Adapter",
1062 .algo = &pci1xxxx_i2c_algo,
1063 .quirks = &pci1xxxx_i2c_quirks,
1064};
1065
1066static int pci1xxxx_i2c_suspend(struct device *dev)
1067{
1068 struct pci1xxxx_i2c *i2c = dev_get_drvdata(dev);
1069 void __iomem *p = i2c->i2c_base + SMBUS_RESET_REG;
1070 struct pci_dev *pdev = to_pci_dev(dev);
1071 u32 regval;
1072
1073 i2c_mark_adapter_suspended(adap: &i2c->adap);
1074
1075 /*
1076 * If the system is put into 'suspend' state when the I2C transfer is in
1077 * progress, wait until the transfer completes.
1078 */
1079 while (i2c->i2c_xfer_in_progress)
1080 msleep(msecs: 20);
1081
1082 pci1xxxx_i2c_config_high_level_intr(i2c, SMBALERT_WAKE_INTR_MASK, enable: true);
1083
1084 /*
1085 * Enable the PERST_DIS bit to mask the PERST from resetting the core
1086 * registers.
1087 */
1088 regval = readl(addr: p);
1089 regval |= PERI_SMBUS_D3_RESET_DIS;
1090 writel(val: regval, addr: p);
1091
1092 /* Enable PCI wake in the PMCSR register. */
1093 device_set_wakeup_enable(dev, enable: true);
1094 pci_wake_from_d3(dev: pdev, enable: true);
1095
1096 return 0;
1097}
1098
1099static int pci1xxxx_i2c_resume(struct device *dev)
1100{
1101 struct pci1xxxx_i2c *i2c = dev_get_drvdata(dev);
1102 void __iomem *p1 = i2c->i2c_base + SMBUS_GEN_INT_STAT_REG_OFF;
1103 void __iomem *p2 = i2c->i2c_base + SMBUS_RESET_REG;
1104 struct pci_dev *pdev = to_pci_dev(dev);
1105 u32 regval;
1106
1107 regval = readw(addr: p1);
1108 writew(val: regval, addr: p1);
1109 pci1xxxx_i2c_config_high_level_intr(i2c, SMBALERT_WAKE_INTR_MASK, enable: false);
1110 regval = readl(addr: p2);
1111 regval &= ~PERI_SMBUS_D3_RESET_DIS;
1112 writel(val: regval, addr: p2);
1113 i2c_mark_adapter_resumed(adap: &i2c->adap);
1114 pci_wake_from_d3(dev: pdev, enable: false);
1115 return 0;
1116}
1117
1118static DEFINE_SIMPLE_DEV_PM_OPS(pci1xxxx_i2c_pm_ops, pci1xxxx_i2c_suspend,
1119 pci1xxxx_i2c_resume);
1120
1121static void pci1xxxx_i2c_shutdown(void *data)
1122{
1123 struct pci1xxxx_i2c *i2c = data;
1124
1125 pci1xxxx_i2c_config_padctrl(i2c, enable: false);
1126 pci1xxxx_i2c_configure_core_reg(i2c, enable: false);
1127}
1128
1129static int pci1xxxx_i2c_probe_pci(struct pci_dev *pdev,
1130 const struct pci_device_id *ent)
1131{
1132 struct device *dev = &pdev->dev;
1133 struct pci1xxxx_i2c *i2c;
1134 int ret;
1135
1136 i2c = devm_kzalloc(dev, size: sizeof(*i2c), GFP_KERNEL);
1137 if (!i2c)
1138 return -ENOMEM;
1139
1140 pci_set_drvdata(pdev, data: i2c);
1141 i2c->i2c_xfer_in_progress = false;
1142
1143 ret = pcim_enable_device(pdev);
1144 if (ret)
1145 return ret;
1146
1147 pci_set_master(dev: pdev);
1148
1149 /*
1150 * We are getting the base address of the SMB core. SMB core uses
1151 * BAR0 and size is 32K.
1152 */
1153 ret = pcim_iomap_regions(pdev, BIT(0), name: pci_name(pdev));
1154 if (ret < 0)
1155 return ret;
1156
1157 i2c->i2c_base = pcim_iomap_table(pdev)[0];
1158 init_completion(x: &i2c->i2c_xfer_done);
1159 pci1xxxx_i2c_init(i2c);
1160
1161 ret = devm_add_action(dev, pci1xxxx_i2c_shutdown, i2c);
1162 if (ret)
1163 return ret;
1164
1165 ret = pci_alloc_irq_vectors(dev: pdev, min_vecs: 1, max_vecs: 1, PCI_IRQ_ALL_TYPES);
1166 if (ret < 0)
1167 return ret;
1168
1169 ret = devm_request_irq(dev, irq: pci_irq_vector(dev: pdev, nr: 0), handler: pci1xxxx_i2c_isr,
1170 irqflags: 0, devname: pci_name(pdev), dev_id: i2c);
1171 if (ret)
1172 return ret;
1173
1174 i2c->adap = pci1xxxx_i2c_ops;
1175 i2c->adap.dev.parent = dev;
1176
1177 snprintf(buf: i2c->adap.name, size: sizeof(i2c->adap.name),
1178 fmt: "MCHP PCI1xxxx i2c adapter at %s", pci_name(pdev));
1179
1180 i2c_set_adapdata(adap: &i2c->adap, data: i2c);
1181
1182 ret = devm_i2c_add_adapter(dev, adapter: &i2c->adap);
1183 if (ret)
1184 return dev_err_probe(dev, err: ret, fmt: "i2c add adapter failed\n");
1185
1186 return 0;
1187}
1188
1189static const struct pci_device_id pci1xxxx_i2c_pci_id_table[] = {
1190 { PCI_VDEVICE(EFAR, 0xA003) },
1191 { PCI_VDEVICE(EFAR, 0xA013) },
1192 { PCI_VDEVICE(EFAR, 0xA023) },
1193 { PCI_VDEVICE(EFAR, 0xA033) },
1194 { PCI_VDEVICE(EFAR, 0xA043) },
1195 { }
1196};
1197MODULE_DEVICE_TABLE(pci, pci1xxxx_i2c_pci_id_table);
1198
1199static struct pci_driver pci1xxxx_i2c_pci_driver = {
1200 .name = "i2c-mchp-pci1xxxx",
1201 .id_table = pci1xxxx_i2c_pci_id_table,
1202 .probe = pci1xxxx_i2c_probe_pci,
1203 .driver = {
1204 .pm = pm_sleep_ptr(&pci1xxxx_i2c_pm_ops),
1205 },
1206};
1207module_pci_driver(pci1xxxx_i2c_pci_driver);
1208
1209MODULE_LICENSE("GPL");
1210MODULE_AUTHOR("Tharun Kumar P<tharunkumar.pasumarthi@microchip.com>");
1211MODULE_AUTHOR("Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>");
1212MODULE_DESCRIPTION("Microchip Technology Inc. pci1xxxx I2C bus driver");
1213

source code of linux/drivers/i2c/busses/i2c-mchp-pci1xxxx.c