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.
21 /* XXX: The SOLO6x10 i2c does not have separate interrupts for each i2c
22 * channel. The bus can only handle one i2c event at a time. The below handles
23 * this all wrong. We should be using the status registers to see if the bus
24 * is in use, and have a global lock to check the status register. Also,
25 * the bulk of the work should be handled out-of-interrupt. The ugly loops
26 * that occur during interrupt scare me. The ISR should merely signal
27 * thread context, ACK the interrupt, and move on. -- BenC */
29 #include <linux/kernel.h>
30 #include <linux/sched/signal.h>
34 u8 solo_i2c_readbyte(struct solo_dev *solo_dev, int id, u8 addr, u8 off)
36 struct i2c_msg msgs[2];
44 msgs[1].flags = I2C_M_RD;
49 i2c_transfer(&solo_dev->i2c_adap[id], msgs, 2);
54 void solo_i2c_writebyte(struct solo_dev *solo_dev, int id, u8 addr,
67 i2c_transfer(&solo_dev->i2c_adap[id], &msgs, 1);
70 static void solo_i2c_flush(struct solo_dev *solo_dev, int wr)
74 ctrl = SOLO_IIC_CH_SET(solo_dev->i2c_id);
76 if (solo_dev->i2c_state == IIC_STATE_START)
77 ctrl |= SOLO_IIC_START;
80 ctrl |= SOLO_IIC_WRITE;
82 ctrl |= SOLO_IIC_READ;
83 if (!(solo_dev->i2c_msg->flags & I2C_M_NO_RD_ACK))
84 ctrl |= SOLO_IIC_ACK_EN;
87 if (solo_dev->i2c_msg_ptr == solo_dev->i2c_msg->len)
88 ctrl |= SOLO_IIC_STOP;
90 solo_reg_write(solo_dev, SOLO_IIC_CTRL, ctrl);
93 static void solo_i2c_start(struct solo_dev *solo_dev)
95 u32 addr = solo_dev->i2c_msg->addr << 1;
97 if (solo_dev->i2c_msg->flags & I2C_M_RD)
100 solo_dev->i2c_state = IIC_STATE_START;
101 solo_reg_write(solo_dev, SOLO_IIC_TXD, addr);
102 solo_i2c_flush(solo_dev, 1);
105 static void solo_i2c_stop(struct solo_dev *solo_dev)
107 solo_irq_off(solo_dev, SOLO_IRQ_IIC);
108 solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0);
109 solo_dev->i2c_state = IIC_STATE_STOP;
110 wake_up(&solo_dev->i2c_wait);
113 static int solo_i2c_handle_read(struct solo_dev *solo_dev)
116 if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) {
117 solo_i2c_flush(solo_dev, 0);
121 solo_dev->i2c_msg_ptr = 0;
123 solo_dev->i2c_msg_num--;
125 if (solo_dev->i2c_msg_num == 0) {
126 solo_i2c_stop(solo_dev);
130 if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) {
131 solo_i2c_start(solo_dev);
133 if (solo_dev->i2c_msg->flags & I2C_M_RD)
136 solo_i2c_stop(solo_dev);
142 static int solo_i2c_handle_write(struct solo_dev *solo_dev)
145 if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) {
146 solo_reg_write(solo_dev, SOLO_IIC_TXD,
147 solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr]);
148 solo_dev->i2c_msg_ptr++;
149 solo_i2c_flush(solo_dev, 1);
153 solo_dev->i2c_msg_ptr = 0;
155 solo_dev->i2c_msg_num--;
157 if (solo_dev->i2c_msg_num == 0) {
158 solo_i2c_stop(solo_dev);
162 if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) {
163 solo_i2c_start(solo_dev);
165 if (solo_dev->i2c_msg->flags & I2C_M_RD)
166 solo_i2c_stop(solo_dev);
174 int solo_i2c_isr(struct solo_dev *solo_dev)
176 u32 status = solo_reg_read(solo_dev, SOLO_IIC_CTRL);
180 if (CHK_FLAGS(status, SOLO_IIC_STATE_TRNS | SOLO_IIC_STATE_SIG_ERR)
181 || solo_dev->i2c_id < 0) {
182 solo_i2c_stop(solo_dev);
186 switch (solo_dev->i2c_state) {
187 case IIC_STATE_START:
188 if (solo_dev->i2c_msg->flags & I2C_M_RD) {
189 solo_dev->i2c_state = IIC_STATE_READ;
190 ret = solo_i2c_handle_read(solo_dev);
194 solo_dev->i2c_state = IIC_STATE_WRITE;
195 case IIC_STATE_WRITE:
196 ret = solo_i2c_handle_write(solo_dev);
200 solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr] =
201 solo_reg_read(solo_dev, SOLO_IIC_RXD);
202 solo_dev->i2c_msg_ptr++;
204 ret = solo_i2c_handle_read(solo_dev);
208 solo_i2c_stop(solo_dev);
214 static int solo_i2c_master_xfer(struct i2c_adapter *adap,
215 struct i2c_msg msgs[], int num)
217 struct solo_dev *solo_dev = adap->algo_data;
218 unsigned long timeout;
223 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
224 if (&solo_dev->i2c_adap[i] == adap)
228 if (i == SOLO_I2C_ADAPTERS)
229 return num; /* XXX Right return value for failure? */
231 mutex_lock(&solo_dev->i2c_mutex);
232 solo_dev->i2c_id = i;
233 solo_dev->i2c_msg = msgs;
234 solo_dev->i2c_msg_num = num;
235 solo_dev->i2c_msg_ptr = 0;
237 solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0);
238 solo_irq_on(solo_dev, SOLO_IRQ_IIC);
239 solo_i2c_start(solo_dev);
244 prepare_to_wait(&solo_dev->i2c_wait, &wait,
247 if (solo_dev->i2c_state == IIC_STATE_STOP)
250 timeout = schedule_timeout(timeout);
254 if (signal_pending(current))
258 finish_wait(&solo_dev->i2c_wait, &wait);
259 ret = num - solo_dev->i2c_msg_num;
260 solo_dev->i2c_state = IIC_STATE_IDLE;
261 solo_dev->i2c_id = -1;
263 mutex_unlock(&solo_dev->i2c_mutex);
268 static u32 solo_i2c_functionality(struct i2c_adapter *adap)
273 static const struct i2c_algorithm solo_i2c_algo = {
274 .master_xfer = solo_i2c_master_xfer,
275 .functionality = solo_i2c_functionality,
278 int solo_i2c_init(struct solo_dev *solo_dev)
283 solo_reg_write(solo_dev, SOLO_IIC_CFG,
284 SOLO_IIC_PRESCALE(8) | SOLO_IIC_ENABLE);
286 solo_dev->i2c_id = -1;
287 solo_dev->i2c_state = IIC_STATE_IDLE;
288 init_waitqueue_head(&solo_dev->i2c_wait);
289 mutex_init(&solo_dev->i2c_mutex);
291 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
292 struct i2c_adapter *adap = &solo_dev->i2c_adap[i];
294 snprintf(adap->name, I2C_NAME_SIZE, "%s I2C %d",
296 adap->algo = &solo_i2c_algo;
297 adap->algo_data = solo_dev;
299 adap->dev.parent = &solo_dev->pdev->dev;
301 ret = i2c_add_adapter(adap);
303 adap->algo_data = NULL;
309 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
310 if (!solo_dev->i2c_adap[i].algo_data)
312 i2c_del_adapter(&solo_dev->i2c_adap[i]);
313 solo_dev->i2c_adap[i].algo_data = NULL;
321 void solo_i2c_exit(struct solo_dev *solo_dev)
325 for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
326 if (!solo_dev->i2c_adap[i].algo_data)
328 i2c_del_adapter(&solo_dev->i2c_adap[i]);
329 solo_dev->i2c_adap[i].algo_data = NULL;