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/arch/powerpc/boot/mv64x60_i2c.c

http://github.com/mirrors/linux
C | 204 lines | 154 code | 29 blank | 21 comment | 22 complexity | 79943539094954840db60a15cf859562 MD5 | raw file
  1/*
  2 * Bootloader version of the i2c driver for the MV64x60.
  3 *
  4 * Author: Dale Farnsworth <dfarnsworth@mvista.com>
  5 * Maintained by: Mark A. Greer <mgreer@mvista.com>
  6 *
  7 * 2003, 2007 (c) MontaVista, Software, Inc.  This file is licensed under
  8 * the terms of the GNU General Public License version 2.  This program is
  9 * licensed "as is" without any warranty of any kind, whether express or
 10 * implied.
 11 */
 12
 13#include <stdarg.h>
 14#include <stddef.h>
 15#include "types.h"
 16#include "elf.h"
 17#include "page.h"
 18#include "string.h"
 19#include "stdio.h"
 20#include "io.h"
 21#include "ops.h"
 22#include "mv64x60.h"
 23
 24/* Register defines */
 25#define MV64x60_I2C_REG_SLAVE_ADDR			0x00
 26#define MV64x60_I2C_REG_DATA				0x04
 27#define MV64x60_I2C_REG_CONTROL				0x08
 28#define MV64x60_I2C_REG_STATUS				0x0c
 29#define MV64x60_I2C_REG_BAUD				0x0c
 30#define MV64x60_I2C_REG_EXT_SLAVE_ADDR			0x10
 31#define MV64x60_I2C_REG_SOFT_RESET			0x1c
 32
 33#define MV64x60_I2C_CONTROL_ACK				0x04
 34#define MV64x60_I2C_CONTROL_IFLG			0x08
 35#define MV64x60_I2C_CONTROL_STOP			0x10
 36#define MV64x60_I2C_CONTROL_START			0x20
 37#define MV64x60_I2C_CONTROL_TWSIEN			0x40
 38#define MV64x60_I2C_CONTROL_INTEN			0x80
 39
 40#define MV64x60_I2C_STATUS_BUS_ERR			0x00
 41#define MV64x60_I2C_STATUS_MAST_START			0x08
 42#define MV64x60_I2C_STATUS_MAST_REPEAT_START		0x10
 43#define MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK		0x18
 44#define MV64x60_I2C_STATUS_MAST_WR_ADDR_NO_ACK		0x20
 45#define MV64x60_I2C_STATUS_MAST_WR_ACK			0x28
 46#define MV64x60_I2C_STATUS_MAST_WR_NO_ACK		0x30
 47#define MV64x60_I2C_STATUS_MAST_LOST_ARB		0x38
 48#define MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK		0x40
 49#define MV64x60_I2C_STATUS_MAST_RD_ADDR_NO_ACK		0x48
 50#define MV64x60_I2C_STATUS_MAST_RD_DATA_ACK		0x50
 51#define MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK		0x58
 52#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_ACK		0xd0
 53#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK	0xd8
 54#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_ACK		0xe0
 55#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK	0xe8
 56#define MV64x60_I2C_STATUS_NO_STATUS			0xf8
 57
 58static u8 *ctlr_base;
 59
 60static int mv64x60_i2c_wait_for_status(int wanted)
 61{
 62	int i;
 63	int status;
 64
 65	for (i=0; i<1000; i++) {
 66		udelay(10);
 67		status = in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_STATUS))
 68			& 0xff;
 69		if (status == wanted)
 70			return status;
 71	}
 72	return -status;
 73}
 74
 75static int mv64x60_i2c_control(int control, int status)
 76{
 77	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
 78	return mv64x60_i2c_wait_for_status(status);
 79}
 80
 81static int mv64x60_i2c_read_byte(int control, int status)
 82{
 83	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
 84	if (mv64x60_i2c_wait_for_status(status) < 0)
 85		return -1;
 86	return in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA)) & 0xff;
 87}
 88
 89static int mv64x60_i2c_write_byte(int data, int control, int status)
 90{
 91	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA), data & 0xff);
 92	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
 93	return mv64x60_i2c_wait_for_status(status);
 94}
 95
 96int mv64x60_i2c_read(u32 devaddr, u8 *buf, u32 offset, u32 offset_size,
 97		 u32 count)
 98{
 99	int i;
100	int data;
101	int control;
102	int status;
103
104	if (ctlr_base == NULL)
105		return -1;
106
107	/* send reset */
108	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SOFT_RESET), 0);
109	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SLAVE_ADDR), 0);
110	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_EXT_SLAVE_ADDR), 0);
111	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_BAUD), (4 << 3) | 0x4);
112
113	if (mv64x60_i2c_control(MV64x60_I2C_CONTROL_TWSIEN,
114				MV64x60_I2C_STATUS_NO_STATUS) < 0)
115		return -1;
116
117	/* send start */
118	control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
119	status = MV64x60_I2C_STATUS_MAST_START;
120	if (mv64x60_i2c_control(control, status) < 0)
121		return -1;
122
123	/* select device for writing */
124	data = devaddr & ~0x1;
125	control = MV64x60_I2C_CONTROL_TWSIEN;
126	status = MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK;
127	if (mv64x60_i2c_write_byte(data, control, status) < 0)
128		return -1;
129
130	/* send offset of data */
131	control = MV64x60_I2C_CONTROL_TWSIEN;
132	status = MV64x60_I2C_STATUS_MAST_WR_ACK;
133	if (offset_size > 1) {
134		if (mv64x60_i2c_write_byte(offset >> 8, control, status) < 0)
135			return -1;
136	}
137	if (mv64x60_i2c_write_byte(offset, control, status) < 0)
138		return -1;
139
140	/* resend start */
141	control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
142	status = MV64x60_I2C_STATUS_MAST_REPEAT_START;
143	if (mv64x60_i2c_control(control, status) < 0)
144		return -1;
145
146	/* select device for reading */
147	data = devaddr | 0x1;
148	control = MV64x60_I2C_CONTROL_TWSIEN;
149	status = MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK;
150	if (mv64x60_i2c_write_byte(data, control, status) < 0)
151		return -1;
152
153	/* read all but last byte of data */
154	control = MV64x60_I2C_CONTROL_ACK | MV64x60_I2C_CONTROL_TWSIEN;
155	status = MV64x60_I2C_STATUS_MAST_RD_DATA_ACK;
156
157	for (i=1; i<count; i++) {
158		data = mv64x60_i2c_read_byte(control, status);
159		if (data < 0) {
160			printf("errors on iteration %d\n", i);
161			return -1;
162		}
163		*buf++ = data;
164	}
165
166	/* read last byte of data */
167	control = MV64x60_I2C_CONTROL_TWSIEN;
168	status = MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK;
169	data = mv64x60_i2c_read_byte(control, status);
170	if (data < 0)
171		return -1;
172	*buf++ = data;
173
174	/* send stop */
175	control = MV64x60_I2C_CONTROL_STOP | MV64x60_I2C_CONTROL_TWSIEN;
176	status = MV64x60_I2C_STATUS_NO_STATUS;
177	if (mv64x60_i2c_control(control, status) < 0)
178		return -1;
179
180	return count;
181}
182
183int mv64x60_i2c_open(void)
184{
185	u32 v;
186	void *devp;
187
188	devp = find_node_by_compatible(NULL, "marvell,mv64360-i2c");
189	if (devp == NULL)
190		goto err_out;
191	if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
192		goto err_out;
193
194	ctlr_base = (u8 *)v;
195	return 0;
196
197err_out:
198	return -1;
199}
200
201void mv64x60_i2c_close(void)
202{
203	ctlr_base = NULL;
204}