2 * Copyright (C) 2010-2013 Bluecherry, LLC <http://www.bluecherrydvr.com>
5 * Ben Collins <bcollins@ubuntu.com>
8 * John Brooks <john.brooks@bluecherry.net>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 /* XXX: The SOLO6x10 i2c does not have separate interrupts for each i2c
26 * channel. The bus can only handle one i2c event at a time. The below handles
27 * this all wrong. We should be using the status registers to see if the bus
28 * is in use, and have a global lock to check the status register. Also,
29 * the bulk of the work should be handled out-of-interrupt. The ugly loops
30 * that occur during interrupt scare me. The ISR should merely signal
31 * thread context, ACK the interrupt, and move on. -- BenC */
33 #include <linux/kernel.h>
37 u8 solo_i2c_readbyte(struct solo_dev *solo_dev, int id, u8 addr, u8 off)
39 struct i2c_msg msgs[2];
47 msgs[1].flags = I2C_M_RD;
52 i2c_transfer(&solo_dev->i2c_adap[id], msgs, 2);
57 void solo_i2c_writebyte(struct solo_dev *solo_dev, int id, u8 addr,
70 i2c_transfer(&solo_dev->i2c_adap[id], &msgs, 1);
73 static void solo_i2c_flush(struct solo_dev *solo_dev, int wr)
77 ctrl = SOLO_IIC_CH_SET(solo_dev->i2c_id);
79 if (solo_dev->i2c_state == IIC_STATE_START)
80 ctrl |= SOLO_IIC_START;
83 ctrl |= SOLO_IIC_WRITE;
85 ctrl |= SOLO_IIC_READ;
86 if (!(solo_dev->i2c_msg->flags & I2C_M_NO_RD_ACK))
87 ctrl |= SOLO_IIC_ACK_EN;
90 if (solo_dev->i2c_msg_ptr == solo_dev->i2c_msg->len)
91 ctrl |= SOLO_IIC_STOP;
93 solo_reg_write(solo_dev, SOLO_IIC_CTRL, ctrl);
96 static void solo_i2c_start(struct solo_dev *solo_dev)
98 u32 addr = solo_dev->i2c_msg->addr << 1;
100 if (solo_dev->i2c_msg->flags & I2C_M_RD)
103 solo_dev->i2c_state = IIC_STATE_START;
104 solo_reg_write(solo_dev, SOLO_IIC_TXD, addr);
105 solo_i2c_flush(solo_dev, 1);
108 static void solo_i2c_stop(struct solo_dev *solo_dev)
110 solo_irq_off(solo_dev, SOLO_IRQ_IIC);
111 solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0);
112 solo_dev->i2c_state = IIC_STATE_STOP;
113 wake_up(&solo_dev->i2c_wait);
116 static int solo_i2c_handle_read(struct solo_dev *solo_dev)
119 if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) {
120 solo_i2c_flush(solo_dev, 0);
124 solo_dev->i2c_msg_ptr = 0;
126 solo_dev->i2c_msg_num--;
128 if (solo_dev->i2c_msg_num == 0) {
129 solo_i2c_stop(solo_dev);
133 if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) {
134 solo_i2c_start(solo_dev);
136 if (solo_dev->i2c_msg->flags & I2C_M_RD)
139 solo_i2c_stop(solo_dev);
145 static int solo_i2c_handle_write(struct solo_dev *solo_dev)
148 if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) {
149 solo_reg_write(solo_dev, SOLO_IIC_TXD,
150 solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr]);
151 solo_dev->i2c_msg_ptr++;
152 solo_i2c_flush(solo_dev, 1);
156 solo_dev->i2c_msg_ptr = 0;
158 solo_dev->i2c_msg_num--;
160 if (solo_dev->i2c_msg_num == 0) {
161 solo_i2c_stop(solo_dev);
165 if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) {
166 solo_i2c_start(solo_dev);
168 if (solo_dev->i2c_msg->flags & I2C_M_RD)
169 solo_i2c_stop(solo_dev);
177 int solo_i2c_isr(struct solo_dev *solo_dev)
179 u32 status = solo_reg_read(solo_dev, SOLO_IIC_CTRL);
183 if (CHK_FLAGS(status, SOLO_IIC_STATE_TRNS | SOLO_IIC_STATE_SIG_ERR)
184 || solo_dev->i2c_id < 0) {
185 solo_i2c_stop(solo_dev);
189 switch (solo_dev->i2c_state) {
190 case IIC_STATE_START:
191 if (solo_dev->i2c_msg->flags & I2C_M_RD) {
192 solo_dev->i2c_state = IIC_STATE_READ;
193 ret = solo_i2c_handle_read(solo_dev);
197 solo_dev->i2c_state = IIC_STATE_WRITE;
198 case IIC_STATE_WRITE:
199 ret = solo_i2c_handle_write(solo_dev);
203 solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr] =
204 solo_reg_read(solo_dev, SOLO_IIC_RXD);
205 solo_dev->i2c_msg_ptr++;
207 ret = solo_i2c_handle_read(solo_dev);
211 solo_i2c_stop(solo_dev);
217 static int solo_i2c_master_xfer(struct i2c_adapter *adap,
218 struct i2c_msg msgs[], int num)
220 struct solo_dev *solo_dev = adap->algo_data;
221 unsigned long timeout;
226 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
227 if (&solo_dev->i2c_adap[i] == adap)
231 if (i == SOLO_I2C_ADAPTERS)
232 return num; /* XXX Right return value for failure? */
234 mutex_lock(&solo_dev->i2c_mutex);
235 solo_dev->i2c_id = i;
236 solo_dev->i2c_msg = msgs;
237 solo_dev->i2c_msg_num = num;
238 solo_dev->i2c_msg_ptr = 0;
240 solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0);
241 solo_irq_on(solo_dev, SOLO_IRQ_IIC);
242 solo_i2c_start(solo_dev);
247 prepare_to_wait(&solo_dev->i2c_wait, &wait,
250 if (solo_dev->i2c_state == IIC_STATE_STOP)
253 timeout = schedule_timeout(timeout);
257 if (signal_pending(current))
261 finish_wait(&solo_dev->i2c_wait, &wait);
262 ret = num - solo_dev->i2c_msg_num;
263 solo_dev->i2c_state = IIC_STATE_IDLE;
264 solo_dev->i2c_id = -1;
266 mutex_unlock(&solo_dev->i2c_mutex);
271 static u32 solo_i2c_functionality(struct i2c_adapter *adap)
276 static const struct i2c_algorithm solo_i2c_algo = {
277 .master_xfer = solo_i2c_master_xfer,
278 .functionality = solo_i2c_functionality,
281 int solo_i2c_init(struct solo_dev *solo_dev)
286 solo_reg_write(solo_dev, SOLO_IIC_CFG,
287 SOLO_IIC_PRESCALE(8) | SOLO_IIC_ENABLE);
289 solo_dev->i2c_id = -1;
290 solo_dev->i2c_state = IIC_STATE_IDLE;
291 init_waitqueue_head(&solo_dev->i2c_wait);
292 mutex_init(&solo_dev->i2c_mutex);
294 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
295 struct i2c_adapter *adap = &solo_dev->i2c_adap[i];
297 snprintf(adap->name, I2C_NAME_SIZE, "%s I2C %d",
299 adap->algo = &solo_i2c_algo;
300 adap->algo_data = solo_dev;
302 adap->dev.parent = &solo_dev->pdev->dev;
304 ret = i2c_add_adapter(adap);
306 adap->algo_data = NULL;
312 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
313 if (!solo_dev->i2c_adap[i].algo_data)
315 i2c_del_adapter(&solo_dev->i2c_adap[i]);
316 solo_dev->i2c_adap[i].algo_data = NULL;
324 void solo_i2c_exit(struct solo_dev *solo_dev)
328 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
329 if (!solo_dev->i2c_adap[i].algo_data)
331 i2c_del_adapter(&solo_dev->i2c_adap[i]);
332 solo_dev->i2c_adap[i].algo_data = NULL;