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Simon Glassabb0b012016-01-17 16:11:44 -07001/*
2 * Copyright (c) 2015 Google, Inc
3 * Written by Simon Glass <sjg@chromium.org>
4 *
Stefan Roeseca6c5e02016-08-09 07:41:15 +02005 * SMBus block read/write support added by Stefan Roese:
6 * Copyright (C) 2016 Stefan Roese <sr@denx.de>
7 *
Simon Glassabb0b012016-01-17 16:11:44 -07008 * SPDX-License-Identifier: GPL-2.0+
9 */
10
11#include <common.h>
12#include <dm.h>
13#include <i2c.h>
Stefan Roeseca6c5e02016-08-09 07:41:15 +020014#include <pci.h>
Simon Glassabb0b012016-01-17 16:11:44 -070015#include <asm/io.h>
16
Stefan Roeseca6c5e02016-08-09 07:41:15 +020017/* PCI Configuration Space (D31:F3): SMBus */
18#define SMB_BASE 0x20
19#define HOSTC 0x40
20#define HST_EN (1 << 0)
21#define SMB_RCV_SLVA 0x09
22
23/* SMBus I/O bits. */
24#define SMBHSTSTAT 0x0
25#define SMBHSTCTL 0x2
26#define SMBHSTCMD 0x3
27#define SMBXMITADD 0x4
28#define SMBHSTDAT0 0x5
29#define SMBHSTDAT1 0x6
30#define SMBBLKDAT 0x7
31#define SMBTRNSADD 0x9
32#define SMBSLVDATA 0xa
33#define SMBAUXCTL 0xd
34#define SMLINK_PIN_CTL 0xe
35#define SMBUS_PIN_CTL 0xf
36
37/* I801 Hosts Status register bits */
38#define SMBHSTSTS_BYTE_DONE 0x80
39#define SMBHSTSTS_INUSE_STS 0x40
40#define SMBHSTSTS_SMBALERT_STS 0x20
41#define SMBHSTSTS_FAILED 0x10
42#define SMBHSTSTS_BUS_ERR 0x08
43#define SMBHSTSTS_DEV_ERR 0x04
44#define SMBHSTSTS_INTR 0x02
45#define SMBHSTSTS_HOST_BUSY 0x01
46
47/* I801 Host Control register bits */
48#define SMBHSTCNT_INTREN 0x01
49#define SMBHSTCNT_KILL 0x02
50#define SMBHSTCNT_LAST_BYTE 0x20
51#define SMBHSTCNT_START 0x40
52#define SMBHSTCNT_PEC_EN 0x80 /* ICH3 and later */
53
54/* Auxiliary control register bits, ICH4+ only */
55#define SMBAUXCTL_CRC 1
56#define SMBAUXCTL_E32B 2
57
58#define SMBUS_TIMEOUT 100 /* 100 ms */
59
60struct intel_i2c {
61 u32 base;
62 int running;
63};
64
65static int smbus_wait_until_ready(u32 base)
Simon Glassabb0b012016-01-17 16:11:44 -070066{
Stefan Roeseca6c5e02016-08-09 07:41:15 +020067 unsigned long ts;
68 u8 byte;
69
70 ts = get_timer(0);
71 do {
72 byte = inb(base + SMBHSTSTAT);
73 if (!(byte & 1))
74 return 0;
75 } while (get_timer(ts) < SMBUS_TIMEOUT);
76
77 return -ETIMEDOUT;
Simon Glassabb0b012016-01-17 16:11:44 -070078}
79
Stefan Roeseca6c5e02016-08-09 07:41:15 +020080static int smbus_wait_until_done(u32 base)
Simon Glassabb0b012016-01-17 16:11:44 -070081{
Stefan Roeseca6c5e02016-08-09 07:41:15 +020082 unsigned long ts;
83 u8 byte;
84
85 ts = get_timer(0);
86 do {
87 byte = inb(base + SMBHSTSTAT);
88 if (!((byte & 1) || (byte & ~((1 << 6) | (1 << 0))) == 0))
89 return 0;
90 } while (get_timer(ts) < SMBUS_TIMEOUT);
91
92 return -ETIMEDOUT;
Simon Glassabb0b012016-01-17 16:11:44 -070093}
94
Stefan Roeseca6c5e02016-08-09 07:41:15 +020095static int smbus_block_read(u32 base, u8 dev, u8 *buffer,
96 int offset, int len)
97{
98 u8 buf_temp[32];
99 int count;
100 int i;
101
102 debug("%s (%d): dev=0x%x offs=0x%x len=0x%x\n",
103 __func__, __LINE__, dev, offset, len);
104 if (smbus_wait_until_ready(base) < 0)
105 return -ETIMEDOUT;
106
107 /* Setup transaction */
108
109 /* Reset the data buffer index */
110 inb(base + SMBHSTCTL);
111
112 /* Set the device I'm talking too */
113 outb(((dev & 0x7f) << 1) | 1, base + SMBXMITADD);
114 /* Set the command/address... */
115 outb(offset & 0xff, base + SMBHSTCMD);
116 /* Set up for a block read */
117 outb((inb(base + SMBHSTCTL) & (~(0x7) << 2)) | (0x5 << 2),
118 (base + SMBHSTCTL));
119 /* Clear any lingering errors, so the transaction will run */
120 outb(inb(base + SMBHSTSTAT), base + SMBHSTSTAT);
121
122 /* Start the command */
123 outb((inb(base + SMBHSTCTL) | SMBHSTCNT_START), base + SMBHSTCTL);
124
125 /* Poll for transaction completion */
126 if (smbus_wait_until_done(base) < 0) {
127 printf("SMBUS read transaction timeout (dev=0x%x)\n", dev);
128 return -ETIMEDOUT;
129 }
130
131 count = inb(base + SMBHSTDAT0);
132 debug("%s (%d): count=%d (len=%d)\n", __func__, __LINE__, count, len);
133 if (count == 0) {
134 debug("ERROR: len=0 on read\n");
135 return -EIO;
136 }
137
138 if (count < len) {
139 debug("ERROR: too few bytes read\n");
140 return -EIO;
141 }
142
143 if (count > 32) {
144 debug("ERROR: count=%d too high\n", count);
145 return -EIO;
146 }
147
148 /* Read all available bytes from buffer */
149 for (i = 0; i < count; i++)
150 buf_temp[i] = inb(base + SMBBLKDAT);
151
152 memcpy(buffer, buf_temp, len);
153
154 /* Return results of transaction */
155 if (!(inb(base + SMBHSTSTAT) & SMBHSTSTS_INTR))
156 return -EIO;
157
158 return 0;
159}
160
161static int smbus_block_write(u32 base, u8 dev, u8 *buffer,
162 int offset, int len)
163{
164 int i;
165
166 debug("%s (%d): dev=0x%x offs=0x%x len=0x%x\n",
167 __func__, __LINE__, dev, offset, len);
168 if (smbus_wait_until_ready(base) < 0)
169 return -ETIMEDOUT;
170
171 /* Setup transaction */
172 /* Set the device I'm talking too */
173 outb(((dev & 0x7f) << 1) & ~0x01, base + SMBXMITADD);
174 /* Set the command/address... */
175 outb(offset, base + SMBHSTCMD);
176 /* Set up for a block write */
177 outb((inb(base + SMBHSTCTL) & (~(0x7) << 2)) | (0x5 << 2),
178 (base + SMBHSTCTL));
179 /* Clear any lingering errors, so the transaction will run */
180 outb(inb(base + SMBHSTSTAT), base + SMBHSTSTAT);
181
182 /* Write count in DAT0 register */
183 outb(len, base + SMBHSTDAT0);
184
185 /* Write data bytes... */
186 for (i = 0; i < len; i++)
187 outb(*buffer++, base + SMBBLKDAT);
188
189 /* Start the command */
190 outb((inb(base + SMBHSTCTL) | SMBHSTCNT_START), base + SMBHSTCTL);
191
192 /* Poll for transaction completion */
193 if (smbus_wait_until_done(base) < 0) {
194 printf("SMBUS write transaction timeout (dev=0x%x)\n", dev);
195 return -ETIMEDOUT;
196 }
197
198 /* Return results of transaction */
199 if (!(inb(base + SMBHSTSTAT) & SMBHSTSTS_INTR))
200 return -EIO;
201
202 return 0;
203}
204
205static int intel_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
206{
207 struct intel_i2c *i2c = dev_get_priv(bus);
208 struct i2c_msg *dmsg, *omsg, dummy;
209
210 debug("i2c_xfer: %d messages\n", nmsgs);
211
212 memset(&dummy, 0, sizeof(struct i2c_msg));
213
214 /*
215 * We expect either two messages (one with an offset and one with the
216 * actucal data) or one message (just data)
217 */
218 if (nmsgs > 2 || nmsgs == 0) {
219 debug("%s: Only one or two messages are supported", __func__);
220 return -EIO;
221 }
222
223 omsg = nmsgs == 1 ? &dummy : msg;
224 dmsg = nmsgs == 1 ? msg : msg + 1;
225
226 if (dmsg->flags & I2C_M_RD)
227 return smbus_block_read(i2c->base, dmsg->addr, &dmsg->buf[0],
228 omsg->buf[0], dmsg->len);
229 else
230 return smbus_block_write(i2c->base, dmsg->addr, &dmsg->buf[1],
231 dmsg->buf[0], dmsg->len - 1);
232}
233
234static int intel_i2c_probe_chip(struct udevice *bus, uint chip_addr,
235 uint chip_flags)
236{
237 struct intel_i2c *i2c = dev_get_priv(bus);
238 u8 buf[4];
239
240 return smbus_block_read(i2c->base, chip_addr, buf, 0, 1);
241}
242
243static int intel_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
Simon Glassabb0b012016-01-17 16:11:44 -0700244{
245 return 0;
246}
247
248static int intel_i2c_probe(struct udevice *dev)
249{
Stefan Roeseca6c5e02016-08-09 07:41:15 +0200250 struct intel_i2c *priv = dev_get_priv(dev);
251 u32 base;
252
253 /* Save base address from PCI BAR */
254 priv->base = (u32)dm_pci_map_bar(dev, PCI_BASE_ADDRESS_4,
255 PCI_REGION_IO);
256 base = priv->base;
Simon Glass0c7645b2016-01-17 16:11:45 -0700257
258 /* Set SMBus enable. */
259 dm_pci_write_config8(dev, HOSTC, HST_EN);
260
Stefan Roeseca6c5e02016-08-09 07:41:15 +0200261 /* Disable interrupts */
262 outb(inb(base + SMBHSTCTL) & ~SMBHSTCNT_INTREN, base + SMBHSTCTL);
Simon Glass0c7645b2016-01-17 16:11:45 -0700263
Stefan Roeseca6c5e02016-08-09 07:41:15 +0200264 /* Set 32-byte data buffer mode */
265 outb(inb(base + SMBAUXCTL) | SMBAUXCTL_E32B, base + SMBAUXCTL);
Simon Glass0c7645b2016-01-17 16:11:45 -0700266
Stefan Roeseca6c5e02016-08-09 07:41:15 +0200267 return 0;
268}
269
270static int intel_i2c_bind(struct udevice *dev)
271{
272 static int num_cards __attribute__ ((section(".data")));
273 char name[20];
274
275 /* Create a unique device name for PCI type devices */
276 if (device_is_on_pci_bus(dev)) {
277 /*
278 * ToDo:
279 * Setting req_seq in the driver is probably not recommended.
280 * But without a DT alias the number is not configured. And
281 * using this driver is impossible for PCIe I2C devices.
282 * This can be removed, once a better (correct) way for this
283 * is found and implemented.
284 */
285 dev->req_seq = num_cards;
286 sprintf(name, "intel_i2c#%u", num_cards++);
287 device_set_name(dev, name);
288 }
Simon Glass0c7645b2016-01-17 16:11:45 -0700289
Simon Glassabb0b012016-01-17 16:11:44 -0700290 return 0;
291}
292
293static const struct dm_i2c_ops intel_i2c_ops = {
294 .xfer = intel_i2c_xfer,
295 .probe_chip = intel_i2c_probe_chip,
296 .set_bus_speed = intel_i2c_set_bus_speed,
297};
298
299static const struct udevice_id intel_i2c_ids[] = {
300 { .compatible = "intel,ich-i2c" },
301 { }
302};
303
304U_BOOT_DRIVER(intel_i2c) = {
305 .name = "i2c_intel",
306 .id = UCLASS_I2C,
307 .of_match = intel_i2c_ids,
Simon Glassabb0b012016-01-17 16:11:44 -0700308 .ops = &intel_i2c_ops,
Stefan Roeseca6c5e02016-08-09 07:41:15 +0200309 .priv_auto_alloc_size = sizeof(struct intel_i2c),
310 .bind = intel_i2c_bind,
Simon Glassabb0b012016-01-17 16:11:44 -0700311 .probe = intel_i2c_probe,
312};
Stefan Roeseca6c5e02016-08-09 07:41:15 +0200313
314static struct pci_device_id intel_smbus_pci_supported[] = {
315 /* Intel BayTrail SMBus on the PCI bus */
316 { PCI_VDEVICE(INTEL, 0x0f12) },
317 /* Intel IvyBridge (Panther Point PCH) SMBus on the PCI bus */
318 { PCI_VDEVICE(INTEL, 0x1e22) },
319 {},
320};
321
322U_BOOT_PCI_DEVICE(intel_i2c, intel_smbus_pci_supported);