aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/ramips/patches-3.8/0066-i2c-MIPS-adds-ralink-I2C-driver.patch
blob: 286020a14857cbbb198a6a5823fc32cd39746564 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
From 68fc18202484e98861ef7eed2a78b64b16c73db9 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 29 Apr 2013 14:40:43 +0200
Subject: [PATCH 66/79] i2c: MIPS: adds ralink I2C driver

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 .../devicetree/bindings/i2c/i2c-ralink.txt         |   27 ++
 drivers/i2c/busses/Kconfig                         |    4 +
 drivers/i2c/busses/Makefile                        |    1 +
 drivers/i2c/busses/i2c-ralink.c                    |  274 ++++++++++++++++++++
 4 files changed, 306 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-ralink.txt
 create mode 100644 drivers/i2c/busses/i2c-ralink.c

diff --git a/Documentation/devicetree/bindings/i2c/i2c-ralink.txt b/Documentation/devicetree/bindings/i2c/i2c-ralink.txt
new file mode 100644
index 0000000..8fa8ac3
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-ralink.txt
@@ -0,0 +1,27 @@
+I2C for Ralink platforms
+
+Required properties :
+- compatible : Must be "link,rt3052-i2c"
+- reg: physical base address of the controller and length of memory mapped
+     region.
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties:
+- Child nodes conforming to i2c bus binding
+
+Example :
+
+palmbus@10000000 {
+	i2c@900 {
+		compatible = "link,rt3052-i2c";
+		reg = <0x900 0x100>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		hwmon@4b {
+			compatible = "national,lm92";
+			reg = <0x4b>;
+		};
+	};
+};
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index bdca511..19b1105 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -604,6 +604,10 @@ config I2C_PXA_SLAVE
 	  is necessary for systems where the PXA may be a target on the
 	  I2C bus.
 
+config I2C_RALINK
+	tristate "Ralink I2C Controller"
+	select OF_I2C
+
 config HAVE_S3C2410_I2C
 	bool
 	help
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 6181f3f..4cf4a88 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -60,6 +60,7 @@ obj-$(CONFIG_I2C_PNX)		+= i2c-pnx.o
 obj-$(CONFIG_I2C_PUV3)		+= i2c-puv3.o
 obj-$(CONFIG_I2C_PXA)		+= i2c-pxa.o
 obj-$(CONFIG_I2C_PXA_PCI)	+= i2c-pxa-pci.o
+obj-$(CONFIG_I2C_RALINK)	+= i2c-ralink.o
 obj-$(CONFIG_I2C_S3C2410)	+= i2c-s3c2410.o
 obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
 obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
diff --git a/drivers/i2c/busses/i2c-ralink.c b/drivers/i2c/busses/i2c-ralink.c
new file mode 100644
index 0000000..b5abf0f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ralink.c
@@ -0,0 +1,274 @@
+/*
+ * drivers/i2c/busses/i2c-ralink.c
+ *
+ * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/reset.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/of_i2c.h>
+#include <linux/err.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define REG_CONFIG_REG		0x00
+#define REG_CLKDIV_REG		0x04
+#define REG_DEVADDR_REG		0x08
+#define REG_ADDR_REG		0x0C
+#define REG_DATAOUT_REG		0x10
+#define REG_DATAIN_REG		0x14
+#define REG_STATUS_REG		0x18
+#define REG_STARTXFR_REG	0x1C
+#define REG_BYTECNT_REG		0x20
+
+#define I2C_STARTERR		BIT(4)
+#define I2C_ACKERR		BIT(3)
+#define I2C_DATARDY		BIT(2)
+#define I2C_SDOEMPTY		BIT(1)
+#define I2C_BUSY		BIT(0)
+
+#define I2C_DEVADLEN_7		(6 << 2)
+#define I2C_ADDRDIS		BIT(1)
+
+#define I2C_RETRY		0x400
+
+#define CLKDIV_VALUE		600
+
+#define READ_CMD		0x01
+#define WRITE_CMD		0x00
+#define READ_BLOCK              64
+
+static void __iomem *membase;
+static struct i2c_adapter *adapter;
+
+static void rt_i2c_w32(u32 val, unsigned reg)
+{
+	iowrite32(val, membase + reg);
+}
+
+static u32 rt_i2c_r32(unsigned reg)
+{
+	return ioread32(membase + reg);
+}
+
+static inline int rt_i2c_wait_rx_done(void)
+{
+	int retries = I2C_RETRY;
+
+	do {
+		if (!retries--)
+			break;
+	} while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
+
+	return (retries < 0);
+}
+
+static inline int rt_i2c_wait_idle(void)
+{
+	int retries = I2C_RETRY;
+
+	do {
+		if (!retries--)
+			break;
+	} while(rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
+
+	return (retries < 0);
+}
+
+static inline int rt_i2c_wait_tx_done(void)
+{
+	int retries = I2C_RETRY;
+
+	do {
+		if (!retries--)
+			break;
+	} while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
+
+	return (retries < 0);
+}
+
+static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
+{
+	int i = 0, j = 0, pos = 0;
+	int nblock = msg->len / READ_BLOCK;
+        int rem = msg->len % READ_BLOCK;
+
+	if (msg->flags & I2C_M_TEN) {
+		printk("10 bits addr not supported\n");
+		return -EINVAL;
+	}
+
+	if (msg->flags & I2C_M_RD) {
+		for (i = 0; i < nblock; i++) {
+			rt_i2c_wait_idle();
+			rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
+			rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
+			for (j = 0; j < READ_BLOCK; j++) {
+				if (rt_i2c_wait_rx_done())
+					return -1;
+				msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
+			}
+		}
+
+		rt_i2c_wait_idle();
+		rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
+		rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
+		for (i = 0; i < rem; i++) {
+			if (rt_i2c_wait_rx_done())
+				return -1;
+			msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
+		}
+	} else {
+		rt_i2c_wait_idle();
+		rt_i2c_w32(msg->len - 1, REG_BYTECNT_REG);
+		rt_i2c_w32(msg->buf[0], REG_DATAOUT_REG);
+		rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
+		for (i = 1; i < msg->len; i++) {
+			rt_i2c_w32(msg->buf[i], REG_DATAOUT_REG);
+			if (rt_i2c_wait_tx_done())
+				return -1;
+		}
+	}
+
+	return msg->len;
+}
+
+static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
+{
+	int i = 0;
+	int ret = 0;
+
+	if (rt_i2c_wait_idle()) {
+		printk("i2c transfer failed\n");
+		return 0;
+	}
+
+	device_reset(a->dev.parent);
+
+	rt_i2c_w32(m->addr, REG_DEVADDR_REG);
+	rt_i2c_w32(I2C_DEVADLEN_7 | I2C_ADDRDIS, REG_CONFIG_REG);
+	rt_i2c_w32(CLKDIV_VALUE, REG_CLKDIV_REG);
+
+	for (i = 0; i < n && !ret; i++)
+		ret = rt_i2c_handle_msg(a, &m[i]);
+
+	if (ret) {
+		printk("i2c transfer failed\n");
+		return 0;
+	}
+
+	return n;
+}
+
+static u32 rt_i2c_func(struct i2c_adapter *a)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm rt_i2c_algo = {
+	.master_xfer	= rt_i2c_master_xfer,
+	.functionality	= rt_i2c_func,
+};
+
+static int rt_i2c_probe(struct platform_device *pdev)
+{
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	int ret;
+
+	if (!res) {
+		dev_err(&pdev->dev, "no memory resource found\n");
+		return -ENODEV;
+	}
+
+	adapter = devm_kzalloc(&pdev->dev, sizeof(struct i2c_adapter), GFP_KERNEL);
+	if (!adapter) {
+		dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
+		return -ENOMEM;
+	}
+
+	membase = devm_request_and_ioremap(&pdev->dev, res);
+	if (IS_ERR(membase))
+		return PTR_ERR(membase);
+
+	strlcpy(adapter->name, dev_name(&pdev->dev), sizeof(adapter->name));
+	adapter->owner = THIS_MODULE;
+	adapter->nr = pdev->id;
+	adapter->timeout = HZ;
+	adapter->algo = &rt_i2c_algo;
+	adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+	adapter->dev.parent = &pdev->dev;
+	adapter->dev.of_node = pdev->dev.of_node;
+
+	ret = i2c_add_numbered_adapter(adapter);
+	if (ret)
+		return ret;
+
+	of_i2c_register_devices(adapter);
+
+	platform_set_drvdata(pdev, adapter);
+
+	dev_info(&pdev->dev, "loaded\n");
+
+	return 0;
+}
+
+static int rt_i2c_remove(struct platform_device *pdev)
+{
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static const struct of_device_id i2c_rt_dt_ids[] = {
+	{ .compatible = "ralink,rt2880-i2c", },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
+
+static struct platform_driver rt_i2c_driver = {
+	.probe		= rt_i2c_probe,
+	.remove		= rt_i2c_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "i2c-ralink",
+		.of_match_table = i2c_rt_dt_ids,
+	},
+};
+
+static int __init i2c_rt_init (void)
+{
+	return platform_driver_register(&rt_i2c_driver);
+}
+subsys_initcall(i2c_rt_init);
+
+static void __exit i2c_rt_exit (void)
+{
+	platform_driver_unregister(&rt_i2c_driver);
+}
+
+module_exit (i2c_rt_exit);
+
+MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
+MODULE_DESCRIPTION("Ralink I2c host driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:Ralink-I2C");
-- 
1.7.10.4