1 // SPDX-License-Identifier: GPL-2.0
3 * Microchip PCI1XXXX I2C adapter driver for PCIe Switch
4 * which has I2C controller in one of its downstream functions
6 * Copyright (C) 2021 - 2022 Microchip Technology Inc.
8 * Authors: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
9 * Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
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>
22 #define SMBUS_MAST_CORE_ADDR_BASE 0x00000
23 #define SMBUS_MAST_SYS_REG_ADDR_BASE 0x01000
25 /* SMB register space. */
26 #define SMB_CORE_CTRL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x00)
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)
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)
36 #define SMB_CORE_CMD_READM BIT(4)
37 #define SMB_CORE_CMD_STOP BIT(2)
38 #define SMB_CORE_CMD_START BIT(0)
40 #define SMB_CORE_CMD_REG_OFF0 (SMBUS_MAST_CORE_ADDR_BASE + 0x0C)
42 #define SMB_CORE_CMD_M_PROCEED BIT(1)
43 #define SMB_CORE_CMD_M_RUN BIT(0)
45 #define SMB_CORE_SR_HOLD_TIME_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x18)
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.
51 #define SR_HOLD_TIME_100K_TICKS 150
52 #define SR_HOLD_TIME_400K_TICKS 20
53 #define SR_HOLD_TIME_1000K_TICKS 12
55 #define SMB_CORE_COMPLETION_REG_OFF3 (SMBUS_MAST_CORE_ADDR_BASE + 0x23)
57 #define COMPLETION_MDONE BIT(6)
58 #define COMPLETION_IDLE BIT(5)
59 #define COMPLETION_MNAKX BIT(0)
61 #define SMB_CORE_IDLE_SCALING_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x24)
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.
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
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.
76 #define FAIR_IDLE_DELAY_100K_TICKS 963
77 #define FAIR_IDLE_DELAY_400K_TICKS 156
78 #define FAIR_IDLE_DELAY_1000K_TICKS 156
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)
87 #define SMB_CORE_CONFIG_REG3 (SMBUS_MAST_CORE_ADDR_BASE + 0x2B)
89 #define SMB_CONFIG3_ENMI BIT(6)
90 #define SMB_CONFIG3_ENIDI BIT(5)
92 #define SMB_CORE_CONFIG_REG2 (SMBUS_MAST_CORE_ADDR_BASE + 0x2A)
93 #define SMB_CORE_CONFIG_REG1 (SMBUS_MAST_CORE_ADDR_BASE + 0x29)
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)
100 #define SMB_CORE_BUS_CLK_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x2C)
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.
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
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.
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
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)
125 #define SMB_CORE_CLK_SYNC_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x3C)
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
132 #define CLK_SYNC_100K 4
133 #define CLK_SYNC_400K 4
134 #define CLK_SYNC_1000K 4
136 #define SMB_CORE_DATA_TIMING_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x40)
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.
145 #define FIRST_START_HOLD_100K_TICKS 23
146 #define FIRST_START_HOLD_400K_TICKS 8
147 #define FIRST_START_HOLD_1000K_TICKS 12
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.
154 #define STOP_SETUP_100K_TICKS 150
155 #define STOP_SETUP_400K_TICKS 20
156 #define STOP_SETUP_1000K_TICKS 12
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.
163 #define RESTART_SETUP_100K_TICKS 156
164 #define RESTART_SETUP_400K_TICKS 20
165 #define RESTART_SETUP_1000K_TICKS 12
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.
172 #define DATA_HOLD_100K_TICKS 12
173 #define DATA_HOLD_400K_TICKS 2
174 #define DATA_HOLD_1000K_TICKS 2
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)
186 #define SMB_CORE_TO_SCALING_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x44)
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)
193 #define BUS_IDLE_MIN_100K_TICKS 36UL
194 #define BUS_IDLE_MIN_400K_TICKS 10UL
195 #define BUS_IDLE_MIN_1000K_TICKS 4UL
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
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
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
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
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
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
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)
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)
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)
242 #define SMBUS_CONTROL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x200)
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)
249 #define I2C_DIRN_WRITE 0
250 #define I2C_DIRN_READ 1
252 #define SMBUS_STATUS_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x204)
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)
260 #define SMBUS_INTR_STAT_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x208)
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)
267 #define SMBUS_INTR_MSK_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x20C)
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)
274 #define ALL_NW_LAYER_INTERRUPTS \
275 (INTR_MSK_DMA_TERM | INTR_MSK_THRESHOLD | INTR_MSK_BUF_FULL | \
278 #define SMBUS_MCU_COUNTER_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x214)
280 #define SMBALERT_MST_PAD_CTRL_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x230)
282 #define SMBALERT_MST_PU BIT(0)
284 #define SMBUS_GEN_INT_STAT_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x23C)
286 #define SMBUS_GEN_INT_MASK_REG_OFF (SMBUS_MAST_CORE_ADDR_BASE + 0x240)
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)
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 | \
300 #define SMBUS_RESET_REG (SMBUS_MAST_CORE_ADDR_BASE + 0x248)
302 #define PERI_SMBUS_D3_RESET_DIS BIT(16)
304 #define SMBUS_MST_BUF (SMBUS_MAST_CORE_ADDR_BASE + 0x280)
306 #define SMBUS_BUF_MAX_SIZE 0x80
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)
313 #define PCI1XXXX_I2C_TIMEOUT_MS 1000
315 /* General Purpose Register. */
316 #define SMB_GPR_REG (SMBUS_MAST_CORE_ADDR_BASE + 0x1000 + 0x0c00 + \
320 #define SMB_GPR_LOCK_REG (SMBUS_MAST_CORE_ADDR_BASE + 0x1000 + 0x0000 + \
323 #define SMBUS_PERI_LOCK BIT(3)
325 struct pci1xxxx_i2c
{
326 struct completion i2c_xfer_done
;
327 bool i2c_xfer_in_progress
;
328 struct i2c_adapter adap
;
329 void __iomem
*i2c_base
;
334 static int set_sys_lock(struct pci1xxxx_i2c
*i2c
)
336 void __iomem
*p
= i2c
->i2c_base
+ SMB_GPR_LOCK_REG
;
339 writel(SMBUS_PERI_LOCK
, p
);
341 if (data
!= SMBUS_PERI_LOCK
)
347 static int release_sys_lock(struct pci1xxxx_i2c
*i2c
)
349 void __iomem
*p
= i2c
->i2c_base
+ SMB_GPR_LOCK_REG
;
353 if (data
!= SMBUS_PERI_LOCK
)
358 if (data
& SMBUS_PERI_LOCK
)
364 static void pci1xxxx_ack_high_level_intr(struct pci1xxxx_i2c
*i2c
, u16 intr_msk
)
366 writew(intr_msk
, i2c
->i2c_base
+ SMBUS_GEN_INT_STAT_REG_OFF
);
369 static void pci1xxxx_i2c_configure_smbalert_pin(struct pci1xxxx_i2c
*i2c
,
372 void __iomem
*p
= i2c
->i2c_base
+ SMBALERT_MST_PAD_CTRL_REG_OFF
;
378 regval
|= SMBALERT_MST_PU
;
380 regval
&= ~SMBALERT_MST_PU
;
385 static void pci1xxxx_i2c_send_start_stop(struct pci1xxxx_i2c
*i2c
, bool start
)
387 void __iomem
*p
= i2c
->i2c_base
+ SMB_CORE_CMD_REG_OFF1
;
393 regval
|= SMB_CORE_CMD_START
;
395 regval
|= SMB_CORE_CMD_STOP
;
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.
405 static void pci1xxxx_i2c_set_clear_FW_ACK(struct pci1xxxx_i2c
*i2c
, bool set
)
410 regval
= SMB_CORE_CTRL_FW_ACK
| SMB_CORE_CTRL_ESO
| SMB_CORE_CTRL_ACK
;
412 regval
= SMB_CORE_CTRL_ESO
| SMB_CORE_CTRL_ACK
;
414 writeb(regval
, i2c
->i2c_base
+ SMB_CORE_CTRL_REG_OFF
);
417 static void pci1xxxx_i2c_buffer_write(struct pci1xxxx_i2c
*i2c
, u8 slaveaddr
,
418 u8 transferlen
, unsigned char *buf
)
420 void __iomem
*p
= i2c
->i2c_base
+ SMBUS_MST_BUF
;
423 writeb(slaveaddr
, p
++);
426 memcpy_toio(p
, buf
, transferlen
);
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.
434 static void pci1xxxx_i2c_enable_ESO(struct pci1xxxx_i2c
*i2c
)
436 writeb(SMB_CORE_CTRL_ESO
, i2c
->i2c_base
+ SMB_CORE_CTRL_REG_OFF
);
439 static void pci1xxxx_i2c_reset_counters(struct pci1xxxx_i2c
*i2c
)
441 void __iomem
*p
= i2c
->i2c_base
+ SMBUS_CONTROL_REG_OFF
;
445 regval
|= CTL_RESET_COUNTERS
;
449 static void pci1xxxx_i2c_set_transfer_dir(struct pci1xxxx_i2c
*i2c
, u8 direction
)
451 void __iomem
*p
= i2c
->i2c_base
+ SMBUS_CONTROL_REG_OFF
;
455 if (direction
== I2C_DIRN_WRITE
)
456 regval
&= ~CTL_TRANSFER_DIR
;
458 regval
|= CTL_TRANSFER_DIR
;
463 static void pci1xxxx_i2c_set_mcu_count(struct pci1xxxx_i2c
*i2c
, u8 count
)
465 writeb(count
, i2c
->i2c_base
+ SMBUS_MCU_COUNTER_REG_OFF
);
468 static void pci1xxxx_i2c_set_read_count(struct pci1xxxx_i2c
*i2c
, u8 readcount
)
470 writeb(readcount
, i2c
->i2c_base
+ SMB_CORE_CMD_REG_OFF3
);
473 static void pci1xxxx_i2c_set_write_count(struct pci1xxxx_i2c
*i2c
, u8 writecount
)
475 writeb(writecount
, i2c
->i2c_base
+ SMB_CORE_CMD_REG_OFF2
);
478 static void pci1xxxx_i2c_set_DMA_run(struct pci1xxxx_i2c
*i2c
)
480 void __iomem
*p
= i2c
->i2c_base
+ SMBUS_CONTROL_REG_OFF
;
488 static void pci1xxxx_i2c_set_mrun_proceed(struct pci1xxxx_i2c
*i2c
)
490 void __iomem
*p
= i2c
->i2c_base
+ SMB_CORE_CMD_REG_OFF0
;
494 regval
|= SMB_CORE_CMD_M_RUN
;
495 regval
|= SMB_CORE_CMD_M_PROCEED
;
499 static void pci1xxxx_i2c_start_DMA(struct pci1xxxx_i2c
*i2c
)
501 pci1xxxx_i2c_set_DMA_run(i2c
);
502 pci1xxxx_i2c_set_mrun_proceed(i2c
);
505 static void pci1xxxx_i2c_config_asr(struct pci1xxxx_i2c
*i2c
, bool enable
)
507 void __iomem
*p
= i2c
->i2c_base
+ SMB_CORE_CONFIG_REG1
;
512 regval
|= SMB_CONFIG1_ASR
;
514 regval
&= ~SMB_CONFIG1_ASR
;
518 static irqreturn_t
pci1xxxx_i2c_isr(int irq
, void *dev
)
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
;
528 * Read the SMBus interrupt status register to see if the
529 * DMA_TERM interrupt has caused this callback.
533 if (reg1
& I2C_BUF_MSTR_INTR_MASK
) {
535 if (reg3
& INTR_STAT_DMA_TERM
) {
536 complete(&i2c
->i2c_xfer_done
);
537 intr_handled
= IRQ_HANDLED
;
538 writeb(INTR_STAT_DMA_TERM
, p2
);
540 pci1xxxx_ack_high_level_intr(i2c
, I2C_BUF_MSTR_INTR_MASK
);
543 if (reg1
& SMBALERT_INTR_MASK
) {
544 intr_handled
= IRQ_HANDLED
;
545 pci1xxxx_ack_high_level_intr(i2c
, SMBALERT_INTR_MASK
);
551 static void pci1xxxx_i2c_set_count(struct pci1xxxx_i2c
*i2c
, u8 mcucount
,
552 u8 writecount
, u8 readcount
)
554 pci1xxxx_i2c_set_mcu_count(i2c
, mcucount
);
555 pci1xxxx_i2c_set_write_count(i2c
, writecount
);
556 pci1xxxx_i2c_set_read_count(i2c
, readcount
);
559 static void pci1xxxx_i2c_set_readm(struct pci1xxxx_i2c
*i2c
, bool enable
)
561 void __iomem
*p
= i2c
->i2c_base
+ SMB_CORE_CMD_REG_OFF1
;
566 regval
|= SMB_CORE_CMD_READM
;
568 regval
&= ~SMB_CORE_CMD_READM
;
573 static void pci1xxxx_ack_nw_layer_intr(struct pci1xxxx_i2c
*i2c
, u8 ack_intr_msk
)
575 writeb(ack_intr_msk
, i2c
->i2c_base
+ SMBUS_INTR_STAT_REG_OFF
);
578 static void pci1xxxx_config_nw_layer_intr(struct pci1xxxx_i2c
*i2c
,
579 u8 intr_msk
, bool enable
)
581 void __iomem
*p
= i2c
->i2c_base
+ SMBUS_INTR_MSK_REG_OFF
;
593 static void pci1xxxx_i2c_config_padctrl(struct pci1xxxx_i2c
*i2c
, bool enable
)
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
;
601 regval
|= I2C_INPUT_EN
| I2C_OUTPUT_EN
;
603 regval
&= ~(I2C_INPUT_EN
| I2C_OUTPUT_EN
);
609 regval
|= I2C_INPUT_EN
| I2C_OUTPUT_EN
;
611 regval
&= ~(I2C_INPUT_EN
| I2C_OUTPUT_EN
);
616 static void pci1xxxx_i2c_set_mode(struct pci1xxxx_i2c
*i2c
)
618 void __iomem
*p
= i2c
->i2c_base
+ SMBUS_CONTROL_REG_OFF
;
622 if (i2c
->flags
& I2C_FLAGS_DIRECT_MODE
)
623 regval
&= ~CTL_HOST_FIFO_ENTRY
;
625 regval
|= CTL_HOST_FIFO_ENTRY
;
630 static void pci1xxxx_i2c_config_high_level_intr(struct pci1xxxx_i2c
*i2c
,
631 u16 intr_msk
, bool enable
)
633 void __iomem
*p
= i2c
->i2c_base
+ SMBUS_GEN_INT_MASK_REG_OFF
;
644 static void pci1xxxx_i2c_configure_core_reg(struct pci1xxxx_i2c
*i2c
, bool enable
)
646 void __iomem
*p1
= i2c
->i2c_base
+ SMB_CORE_CONFIG_REG1
;
647 void __iomem
*p3
= i2c
->i2c_base
+ SMB_CORE_CONFIG_REG3
;
654 reg1
|= SMB_CONFIG1_ENAB
| SMB_CONFIG1_FEN
;
655 reg3
|= SMB_CONFIG3_ENMI
| SMB_CONFIG3_ENIDI
;
657 reg1
&= ~(SMB_CONFIG1_ENAB
| SMB_CONFIG1_FEN
);
658 reg3
&= ~(SMB_CONFIG3_ENMI
| SMB_CONFIG3_ENIDI
);
665 static void pci1xxxx_i2c_set_freq(struct pci1xxxx_i2c
*i2c
)
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
;
676 case I2C_MAX_STANDARD_MODE_FREQ
:
677 writeb(SR_HOLD_TIME_100K_TICKS
, p_hold_time
);
678 writel(SMB_IDLE_SCALING_100K
, p_idle_scaling
);
679 writew(BUS_CLK_100K
, p_clk_reg
);
680 writel(CLK_SYNC_100K
, p_clk_sync
);
681 writel(DATA_TIMING_100K
, p_data_timing
);
682 writel(TO_SCALING_100K
, p_to_scaling
);
685 case I2C_MAX_FAST_MODE_PLUS_FREQ
:
686 writeb(SR_HOLD_TIME_1000K_TICKS
, p_hold_time
);
687 writel(SMB_IDLE_SCALING_1000K
, p_idle_scaling
);
688 writew(BUS_CLK_1000K
, p_clk_reg
);
689 writel(CLK_SYNC_1000K
, p_clk_sync
);
690 writel(DATA_TIMING_1000K
, p_data_timing
);
691 writel(TO_SCALING_1000K
, p_to_scaling
);
694 case I2C_MAX_FAST_MODE_FREQ
:
696 writeb(SR_HOLD_TIME_400K_TICKS
, p_hold_time
);
697 writel(SMB_IDLE_SCALING_400K
, p_idle_scaling
);
698 writew(BUS_CLK_400K
, p_clk_reg
);
699 writel(CLK_SYNC_400K
, p_clk_sync
);
700 writel(DATA_TIMING_400K
, p_data_timing
);
701 writel(TO_SCALING_400K
, p_to_scaling
);
706 static void pci1xxxx_i2c_init(struct pci1xxxx_i2c
*i2c
)
708 void __iomem
*p2
= i2c
->i2c_base
+ SMBUS_STATUS_REG_OFF
;
709 void __iomem
*p1
= i2c
->i2c_base
+ SMB_GPR_REG
;
713 ret
= set_sys_lock(i2c
);
716 * Configure I2C Fast Mode as default frequency if unable
717 * to acquire sys lock.
722 release_sys_lock(i2c
);
727 i2c
->freq
= I2C_MAX_FAST_MODE_FREQ
;
728 pci1xxxx_i2c_set_freq(i2c
);
731 i2c
->freq
= I2C_MAX_STANDARD_MODE_FREQ
;
732 pci1xxxx_i2c_set_freq(i2c
);
735 i2c
->freq
= I2C_MAX_FAST_MODE_PLUS_FREQ
;
736 pci1xxxx_i2c_set_freq(i2c
);
743 pci1xxxx_i2c_config_padctrl(i2c
, true);
744 i2c
->flags
|= I2C_FLAGS_DIRECT_MODE
;
745 pci1xxxx_i2c_set_mode(i2c
);
748 * Added as a precaution since BUF_EMPTY in status register
749 * also trigered an Interrupt.
751 writeb(STA_BUF_EMPTY
, p2
);
753 /* Configure core I2c control registers. */
754 pci1xxxx_i2c_configure_core_reg(i2c
, true);
757 * Enable pull-up for the SMB alert pin which is just used for
760 pci1xxxx_i2c_configure_smbalert_pin(i2c
, true);
763 static void pci1xxxx_i2c_clear_flags(struct pci1xxxx_i2c
*i2c
)
767 /* Reset the internal buffer counters. */
768 pci1xxxx_i2c_reset_counters(i2c
);
770 /* Clear low level interrupts. */
771 regval
= COMPLETION_MNAKX
| COMPLETION_IDLE
| COMPLETION_MDONE
;
772 writeb(regval
, i2c
->i2c_base
+ SMB_CORE_COMPLETION_REG_OFF3
);
773 reinit_completion(&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
);
778 static int pci1xxxx_i2c_read(struct pci1xxxx_i2c
*i2c
, u8 slaveaddr
,
779 unsigned char *buf
, u16 total_len
)
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
;
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
, true);
796 pci1xxxx_i2c_config_high_level_intr(i2c
, I2C_BUF_MSTR_INTR_MASK
, true);
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.
807 for (count
= 0; count
< total_len
; count
+= transferlen
) {
810 * Before start of any transaction clear the existing
811 * START/STOP conditions.
814 remainingbytes
= total_len
- count
;
815 transferlen
= min_t(u16
, remainingbytes
, SMBUS_BUF_MAX_SIZE
);
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.
826 if ((count
+ transferlen
>= total_len
) &&
827 (i2c
->flags
& I2C_FLAGS_STOP
)) {
828 pci1xxxx_i2c_set_clear_FW_ACK(i2c
, false);
829 pci1xxxx_i2c_send_start_stop(i2c
, 0);
831 pci1xxxx_i2c_set_clear_FW_ACK(i2c
, true);
834 /* Send START bit for the first transaction. */
836 pci1xxxx_i2c_set_transfer_dir(i2c
, I2C_DIRN_WRITE
);
837 pci1xxxx_i2c_send_start_stop(i2c
, 1);
839 /* Write I2c buffer with just the slave addr. */
840 pci1xxxx_i2c_buffer_write(i2c
, slaveaddr
, 0, NULL
);
842 /* Set the count. Readcount is the transfer bytes. */
843 pci1xxxx_i2c_set_count(i2c
, 1, 1, transferlen
);
846 * Set the Auto_start_read bit so that the HW itself
847 * will take care of the read phase.
849 pci1xxxx_i2c_config_asr(i2c
, true);
850 if (i2c
->flags
& I2C_FLAGS_SMB_BLK_READ
)
851 pci1xxxx_i2c_set_readm(i2c
, true);
853 pci1xxxx_i2c_set_count(i2c
, 0, 0, transferlen
);
854 pci1xxxx_i2c_config_asr(i2c
, false);
855 pci1xxxx_i2c_clear_flags(i2c
);
856 pci1xxxx_i2c_set_transfer_dir(i2c
, I2C_DIRN_READ
);
860 pci1xxxx_i2c_start_DMA(i2c
);
862 /* Wait for the DMA_TERM interrupt. */
863 time_left
= wait_for_completion_timeout(&i2c
->i2c_xfer_done
,
864 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
);
872 /* Read the completion reg to know the reason for DMA_TERM. */
875 /* Slave did not respond. */
876 if (regval
& COMPLETION_MNAKX
) {
877 writeb(COMPLETION_MNAKX
, p2
);
882 if (i2c
->flags
& I2C_FLAGS_SMB_BLK_READ
) {
885 memcpy_fromio(&buf
[1], p3
+ 1, read_count
);
887 memcpy_fromio(&buf
[count
], p3
, transferlen
);
892 /* Disable all the interrupts. */
893 pci1xxxx_config_nw_layer_intr(i2c
, INTR_MSK_DMA_TERM
, false);
894 pci1xxxx_i2c_config_high_level_intr(i2c
, I2C_BUF_MSTR_INTR_MASK
, false);
895 pci1xxxx_i2c_config_asr(i2c
, false);
899 static int pci1xxxx_i2c_write(struct pci1xxxx_i2c
*i2c
, u8 slaveaddr
,
900 unsigned char *buf
, u16 total_len
)
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
;
912 /* Enable I2C host controller by setting the ESO bit in the CONTROL REG. */
913 pci1xxxx_i2c_enable_ESO(i2c
);
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
, true);
918 pci1xxxx_i2c_config_high_level_intr(i2c
, I2C_BUF_MSTR_INTR_MASK
, true);
921 * The i2c transfer could be more than 128 bytes. Our Core is
922 * capable of only sending 128 at a time.
924 for (count
= 0; count
< total_len
; count
+= transferlen
) {
926 * Before start of any transaction clear the existing
927 * START/STOP conditions.
930 pci1xxxx_i2c_clear_flags(i2c
);
931 remainingbytes
= total_len
- count
;
933 /* If it is the starting of the transaction send START. */
935 pci1xxxx_i2c_send_start_stop(i2c
, 1);
937 /* -1 for the slave address. */
938 transferlen
= min_t(u16
, SMBUS_BUF_MAX_SIZE
- 1,
940 pci1xxxx_i2c_buffer_write(i2c
, slaveaddr
,
941 transferlen
, &buf
[count
]);
943 * The actual number of bytes written on the I2C bus
944 * is including the slave address.
946 actualwritelen
= transferlen
+ 1;
948 transferlen
= min_t(u16
, SMBUS_BUF_MAX_SIZE
, remainingbytes
);
949 pci1xxxx_i2c_buffer_write(i2c
, 0, transferlen
, &buf
[count
]);
950 actualwritelen
= transferlen
;
953 pci1xxxx_i2c_set_count(i2c
, actualwritelen
, actualwritelen
, 0);
956 * Send STOP only when I2C_FLAGS_STOP bit is set in the flags and
957 * only for the last transaction.
959 if (remainingbytes
<= transferlen
&&
960 (i2c
->flags
& I2C_FLAGS_STOP
))
961 pci1xxxx_i2c_send_start_stop(i2c
, 0);
963 pci1xxxx_i2c_start_DMA(i2c
);
966 * Wait for the DMA_TERM interrupt.
968 time_left
= wait_for_completion_timeout(&i2c
->i2c_xfer_done
,
969 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
);
978 if (regval
& COMPLETION_MNAKX
) {
979 writeb(COMPLETION_MNAKX
, p2
);
985 /* Disable all the interrupts. */
986 pci1xxxx_config_nw_layer_intr(i2c
, INTR_MSK_DMA_TERM
, false);
987 pci1xxxx_i2c_config_high_level_intr(i2c
, I2C_BUF_MSTR_INTR_MASK
, false);
992 static int pci1xxxx_i2c_xfer(struct i2c_adapter
*adap
,
993 struct i2c_msg
*msgs
, int num
)
995 struct pci1xxxx_i2c
*i2c
= i2c_get_adapdata(adap
);
1000 i2c
->i2c_xfer_in_progress
= true;
1001 for (i
= 0; i
< num
; i
++) {
1002 slaveaddr
= i2c_8bit_addr_from_msg(&msgs
[i
]);
1005 * Send the STOP bit if the transfer is the final one or
1006 * if the I2C_M_STOP flag is set.
1008 if ((i
== num
- 1) || (msgs
[i
].flags
& I2C_M_STOP
))
1009 i2c
->flags
|= I2C_FLAGS_STOP
;
1011 i2c
->flags
&= ~I2C_FLAGS_STOP
;
1013 if (msgs
[i
].flags
& I2C_M_RECV_LEN
)
1014 i2c
->flags
|= I2C_FLAGS_SMB_BLK_READ
;
1016 i2c
->flags
&= ~I2C_FLAGS_SMB_BLK_READ
;
1018 if (msgs
[i
].flags
& I2C_M_RD
)
1019 retval
= pci1xxxx_i2c_read(i2c
, slaveaddr
,
1020 msgs
[i
].buf
, msgs
[i
].len
);
1022 retval
= pci1xxxx_i2c_write(i2c
, slaveaddr
,
1023 msgs
[i
].buf
, msgs
[i
].len
);
1028 i2c
->i2c_xfer_in_progress
= false;
1037 * List of supported functions by the driver.
1039 static u32
pci1xxxx_i2c_get_funcs(struct i2c_adapter
*adap
)
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
;
1050 static const struct i2c_algorithm pci1xxxx_i2c_algo
= {
1051 .master_xfer
= pci1xxxx_i2c_xfer
,
1052 .functionality
= pci1xxxx_i2c_get_funcs
,
1055 static const struct i2c_adapter_quirks pci1xxxx_i2c_quirks
= {
1056 .flags
= I2C_AQ_NO_ZERO_LEN
,
1059 static 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
,
1066 static int pci1xxxx_i2c_suspend(struct device
*dev
)
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
);
1073 i2c_mark_adapter_suspended(&i2c
->adap
);
1076 * If the system is put into 'suspend' state when the I2C transfer is in
1077 * progress, wait until the transfer completes.
1079 while (i2c
->i2c_xfer_in_progress
)
1082 pci1xxxx_i2c_config_high_level_intr(i2c
, SMBALERT_WAKE_INTR_MASK
, true);
1085 * Enable the PERST_DIS bit to mask the PERST from resetting the core
1089 regval
|= PERI_SMBUS_D3_RESET_DIS
;
1092 /* Enable PCI wake in the PMCSR register. */
1093 device_set_wakeup_enable(dev
, true);
1094 pci_wake_from_d3(pdev
, true);
1099 static int pci1xxxx_i2c_resume(struct device
*dev
)
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
);
1109 pci1xxxx_i2c_config_high_level_intr(i2c
, SMBALERT_WAKE_INTR_MASK
, false);
1111 regval
&= ~PERI_SMBUS_D3_RESET_DIS
;
1113 i2c_mark_adapter_resumed(&i2c
->adap
);
1114 pci_wake_from_d3(pdev
, false);
1118 static DEFINE_SIMPLE_DEV_PM_OPS(pci1xxxx_i2c_pm_ops
, pci1xxxx_i2c_suspend
,
1119 pci1xxxx_i2c_resume
);
1121 static void pci1xxxx_i2c_shutdown(void *data
)
1123 struct pci1xxxx_i2c
*i2c
= data
;
1125 pci1xxxx_i2c_config_padctrl(i2c
, false);
1126 pci1xxxx_i2c_configure_core_reg(i2c
, false);
1129 static int pci1xxxx_i2c_probe_pci(struct pci_dev
*pdev
,
1130 const struct pci_device_id
*ent
)
1132 struct device
*dev
= &pdev
->dev
;
1133 struct pci1xxxx_i2c
*i2c
;
1136 i2c
= devm_kzalloc(dev
, sizeof(*i2c
), GFP_KERNEL
);
1140 pci_set_drvdata(pdev
, i2c
);
1141 i2c
->i2c_xfer_in_progress
= false;
1143 ret
= pcim_enable_device(pdev
);
1147 pci_set_master(pdev
);
1150 * We are getting the base address of the SMB core. SMB core uses
1151 * BAR0 and size is 32K.
1153 ret
= pcim_iomap_regions(pdev
, BIT(0), pci_name(pdev
));
1157 i2c
->i2c_base
= pcim_iomap_table(pdev
)[0];
1158 init_completion(&i2c
->i2c_xfer_done
);
1159 pci1xxxx_i2c_init(i2c
);
1161 ret
= devm_add_action(dev
, pci1xxxx_i2c_shutdown
, i2c
);
1165 ret
= pci_alloc_irq_vectors(pdev
, 1, 1, PCI_IRQ_ALL_TYPES
);
1169 ret
= devm_request_irq(dev
, pci_irq_vector(pdev
, 0), pci1xxxx_i2c_isr
,
1170 0, pci_name(pdev
), i2c
);
1174 i2c
->adap
= pci1xxxx_i2c_ops
;
1175 i2c
->adap
.dev
.parent
= dev
;
1177 snprintf(i2c
->adap
.name
, sizeof(i2c
->adap
.name
),
1178 "MCHP PCI1xxxx i2c adapter at %s", pci_name(pdev
));
1180 i2c_set_adapdata(&i2c
->adap
, i2c
);
1182 ret
= devm_i2c_add_adapter(dev
, &i2c
->adap
);
1184 return dev_err_probe(dev
, ret
, "i2c add adapter failed\n");
1189 static 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) },
1197 MODULE_DEVICE_TABLE(pci
, pci1xxxx_i2c_pci_id_table
);
1199 static 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
,
1204 .pm
= pm_sleep_ptr(&pci1xxxx_i2c_pm_ops
),
1207 module_pci_driver(pci1xxxx_i2c_pci_driver
);
1209 MODULE_LICENSE("GPL");
1210 MODULE_AUTHOR("Tharun Kumar P<tharunkumar.pasumarthi@microchip.com>");
1211 MODULE_AUTHOR("Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>");
1212 MODULE_DESCRIPTION("Microchip Technology Inc. pci1xxxx I2C bus driver");