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/drivers/i2c/algos/i2c-algo-sibyte.c

https://bitbucket.org/evzijst/gittest
C | 222 lines | 148 code | 38 blank | 36 comment | 23 complexity | b72b1c8b8b1e84e2f2773d54dd86cb8e MD5 | raw file
  1/* ------------------------------------------------------------------------- */
  2/* i2c-algo-sibyte.c i2c driver algorithms for bit-shift adapters		     */
  3/* ------------------------------------------------------------------------- */
  4/*   Copyright (C) 2001,2002,2003 Broadcom Corporation
  5     Copyright (C) 1995-2000 Simon G. Vogl
  6
  7    This program is free software; you can redistribute it and/or modify
  8    it under the terms of the GNU General Public License as published by
  9    the Free Software Foundation; either version 2 of the License, or
 10    (at your option) any later version.
 11
 12    This program is distributed in the hope that it will be useful,
 13    but WITHOUT ANY WARRANTY; without even the implied warranty of
 14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15    GNU General Public License for more details.
 16
 17    You should have received a copy of the GNU General Public License
 18    along with this program; if not, write to the Free Software
 19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     */
 20/* ------------------------------------------------------------------------- */
 21
 22/* With some changes from Ky�sti M�lkki <kmalkki@cc.hut.fi> and even
 23   Frodo Looijaard <frodol@dds.nl>.  */
 24
 25/* Ported for SiByte SOCs by Broadcom Corporation.  */
 26
 27#include <linux/config.h>
 28#include <linux/kernel.h>
 29#include <linux/module.h>
 30#include <linux/init.h>
 31
 32#include <asm/io.h>
 33#include <asm/sibyte/sb1250_regs.h>
 34#include <asm/sibyte/sb1250_smbus.h>
 35
 36#include <linux/i2c.h>
 37#include <linux/i2c-algo-sibyte.h>
 38
 39/* ----- global defines ----------------------------------------------- */
 40#define SMB_CSR(a,r) ((long)(a->reg_base + r))
 41
 42/* ----- global variables ---------------------------------------------	*/
 43
 44/* module parameters:
 45 */
 46static int bit_scan=0;	/* have a look at what's hanging 'round		*/
 47
 48
 49static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, 
 50                      unsigned short flags, char read_write,
 51                      u8 command, int size, union i2c_smbus_data * data)
 52{
 53	struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
 54        int data_bytes = 0;
 55        int error;
 56
 57        while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
 58                ;
 59
 60        switch (size) {
 61        case I2C_SMBUS_QUICK:
 62                csr_out32((V_SMB_ADDR(addr) | (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
 63			   V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
 64                break;
 65        case I2C_SMBUS_BYTE:
 66                if (read_write == I2C_SMBUS_READ) {
 67                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
 68				  SMB_CSR(adap, R_SMB_START));
 69                        data_bytes = 1;
 70                } else {
 71                        csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
 72                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
 73				  SMB_CSR(adap, R_SMB_START));
 74                }
 75                break;
 76        case I2C_SMBUS_BYTE_DATA:
 77                csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
 78                if (read_write == I2C_SMBUS_READ) {
 79                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
 80				  SMB_CSR(adap, R_SMB_START));
 81                        data_bytes = 1;
 82                } else {
 83                        csr_out32(V_SMB_LB(data->byte), SMB_CSR(adap, R_SMB_DATA));
 84                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
 85				  SMB_CSR(adap, R_SMB_START));
 86                }
 87                break;
 88        case I2C_SMBUS_WORD_DATA:
 89                csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
 90                if (read_write == I2C_SMBUS_READ) {
 91                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
 92				  SMB_CSR(adap, R_SMB_START));
 93                        data_bytes = 2;
 94                } else {
 95                        csr_out32(V_SMB_LB(data->word & 0xff), SMB_CSR(adap, R_SMB_DATA));
 96                        csr_out32(V_SMB_MB(data->word >> 8), SMB_CSR(adap, R_SMB_DATA));
 97                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
 98				  SMB_CSR(adap, R_SMB_START));
 99                }
100                break;
101        default:
102                return -1;      /* XXXKW better error code? */
103        }
104
105        while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
106                ;
107
108        error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
109        if (error & M_SMB_ERROR) {
110                /* Clear error bit by writing a 1 */
111                csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
112                return -1;      /* XXXKW better error code? */
113        }
114
115        if (data_bytes == 1)
116                data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
117        if (data_bytes == 2)
118                data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
119
120        return 0;
121}
122
123static int algo_control(struct i2c_adapter *adapter, 
124	unsigned int cmd, unsigned long arg)
125{
126	return 0;
127}
128
129static u32 bit_func(struct i2c_adapter *adap)
130{
131	return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
132                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
133}
134
135
136/* -----exported algorithm data: -------------------------------------	*/
137
138static struct i2c_algorithm i2c_sibyte_algo = {
139	.name		= "SiByte algorithm",
140	.id		= I2C_ALGO_SIBYTE,
141	.smbus_xfer	= smbus_xfer,
142	.algo_control	= algo_control, /* ioctl */
143	.functionality	= bit_func,
144};
145
146/* 
147 * registering functions to load algorithms at runtime 
148 */
149int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
150{
151	int i;
152	struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
153
154	/* register new adapter to i2c module... */
155
156	i2c_adap->id |= i2c_sibyte_algo.id;
157	i2c_adap->algo = &i2c_sibyte_algo;
158        
159        /* Set the frequency to 100 kHz */
160        csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
161        csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
162
163	/* scan bus */
164	if (bit_scan) {
165                union i2c_smbus_data data;
166                int rc;
167		printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n",
168		       i2c_adap->name);
169		for (i = 0x00; i < 0x7f; i++) {
170                        /* XXXKW is this a realistic probe? */
171                        rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0,
172                                        I2C_SMBUS_BYTE_DATA, &data);
173			if (!rc) {
174				printk("(%02x)",i); 
175			} else 
176				printk("."); 
177		}
178		printk("\n");
179	}
180
181	i2c_add_adapter(i2c_adap);
182
183	return 0;
184}
185
186
187int i2c_sibyte_del_bus(struct i2c_adapter *adap)
188{
189	int res;
190
191	if ((res = i2c_del_adapter(adap)) < 0)
192		return res;
193
194	return 0;
195}
196
197int __init i2c_algo_sibyte_init (void)
198{
199	printk("i2c-algo-sibyte.o: i2c SiByte algorithm module\n");
200	return 0;
201}
202
203
204EXPORT_SYMBOL(i2c_sibyte_add_bus);
205EXPORT_SYMBOL(i2c_sibyte_del_bus);
206
207#ifdef MODULE
208MODULE_AUTHOR("Kip Walker, Broadcom Corp.");
209MODULE_DESCRIPTION("SiByte I2C-Bus algorithm");
210MODULE_PARM(bit_scan, "i");
211MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus");
212MODULE_LICENSE("GPL");
213
214int init_module(void) 
215{
216	return i2c_algo_sibyte_init();
217}
218
219void cleanup_module(void) 
220{
221}
222#endif