diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/media/pci/solo6x10/solo6x10-i2c.c |
Initial import
Diffstat (limited to 'drivers/media/pci/solo6x10/solo6x10-i2c.c')
-rw-r--r-- | drivers/media/pci/solo6x10/solo6x10-i2c.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/media/pci/solo6x10/solo6x10-i2c.c b/drivers/media/pci/solo6x10/solo6x10-i2c.c new file mode 100644 index 000000000..c908672b2 --- /dev/null +++ b/drivers/media/pci/solo6x10/solo6x10-i2c.c @@ -0,0 +1,330 @@ +/* + * Copyright (C) 2010-2013 Bluecherry, LLC <http://www.bluecherrydvr.com> + * + * Original author: + * Ben Collins <bcollins@ubuntu.com> + * + * Additional work by: + * John Brooks <john.brooks@bluecherry.net> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + */ + +/* XXX: The SOLO6x10 i2c does not have separate interrupts for each i2c + * channel. The bus can only handle one i2c event at a time. The below handles + * this all wrong. We should be using the status registers to see if the bus + * is in use, and have a global lock to check the status register. Also, + * the bulk of the work should be handled out-of-interrupt. The ugly loops + * that occur during interrupt scare me. The ISR should merely signal + * thread context, ACK the interrupt, and move on. -- BenC */ + +#include <linux/kernel.h> + +#include "solo6x10.h" + +u8 solo_i2c_readbyte(struct solo_dev *solo_dev, int id, u8 addr, u8 off) +{ + struct i2c_msg msgs[2]; + u8 data; + + msgs[0].flags = 0; + msgs[0].addr = addr; + msgs[0].len = 1; + msgs[0].buf = &off; + + msgs[1].flags = I2C_M_RD; + msgs[1].addr = addr; + msgs[1].len = 1; + msgs[1].buf = &data; + + i2c_transfer(&solo_dev->i2c_adap[id], msgs, 2); + + return data; +} + +void solo_i2c_writebyte(struct solo_dev *solo_dev, int id, u8 addr, + u8 off, u8 data) +{ + struct i2c_msg msgs; + u8 buf[2]; + + buf[0] = off; + buf[1] = data; + msgs.flags = 0; + msgs.addr = addr; + msgs.len = 2; + msgs.buf = buf; + + i2c_transfer(&solo_dev->i2c_adap[id], &msgs, 1); +} + +static void solo_i2c_flush(struct solo_dev *solo_dev, int wr) +{ + u32 ctrl; + + ctrl = SOLO_IIC_CH_SET(solo_dev->i2c_id); + + if (solo_dev->i2c_state == IIC_STATE_START) + ctrl |= SOLO_IIC_START; + + if (wr) { + ctrl |= SOLO_IIC_WRITE; + } else { + ctrl |= SOLO_IIC_READ; + if (!(solo_dev->i2c_msg->flags & I2C_M_NO_RD_ACK)) + ctrl |= SOLO_IIC_ACK_EN; + } + + if (solo_dev->i2c_msg_ptr == solo_dev->i2c_msg->len) + ctrl |= SOLO_IIC_STOP; + + solo_reg_write(solo_dev, SOLO_IIC_CTRL, ctrl); +} + +static void solo_i2c_start(struct solo_dev *solo_dev) +{ + u32 addr = solo_dev->i2c_msg->addr << 1; + + if (solo_dev->i2c_msg->flags & I2C_M_RD) + addr |= 1; + + solo_dev->i2c_state = IIC_STATE_START; + solo_reg_write(solo_dev, SOLO_IIC_TXD, addr); + solo_i2c_flush(solo_dev, 1); +} + +static void solo_i2c_stop(struct solo_dev *solo_dev) +{ + solo_irq_off(solo_dev, SOLO_IRQ_IIC); + solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0); + solo_dev->i2c_state = IIC_STATE_STOP; + wake_up(&solo_dev->i2c_wait); +} + +static int solo_i2c_handle_read(struct solo_dev *solo_dev) +{ +prepare_read: + if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) { + solo_i2c_flush(solo_dev, 0); + return 0; + } + + solo_dev->i2c_msg_ptr = 0; + solo_dev->i2c_msg++; + solo_dev->i2c_msg_num--; + + if (solo_dev->i2c_msg_num == 0) { + solo_i2c_stop(solo_dev); + return 0; + } + + if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) { + solo_i2c_start(solo_dev); + } else { + if (solo_dev->i2c_msg->flags & I2C_M_RD) + goto prepare_read; + else + solo_i2c_stop(solo_dev); + } + + return 0; +} + +static int solo_i2c_handle_write(struct solo_dev *solo_dev) +{ +retry_write: + if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) { + solo_reg_write(solo_dev, SOLO_IIC_TXD, + solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr]); + solo_dev->i2c_msg_ptr++; + solo_i2c_flush(solo_dev, 1); + return 0; + } + + solo_dev->i2c_msg_ptr = 0; + solo_dev->i2c_msg++; + solo_dev->i2c_msg_num--; + + if (solo_dev->i2c_msg_num == 0) { + solo_i2c_stop(solo_dev); + return 0; + } + + if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) { + solo_i2c_start(solo_dev); + } else { + if (solo_dev->i2c_msg->flags & I2C_M_RD) + solo_i2c_stop(solo_dev); + else + goto retry_write; + } + + return 0; +} + +int solo_i2c_isr(struct solo_dev *solo_dev) +{ + u32 status = solo_reg_read(solo_dev, SOLO_IIC_CTRL); + int ret = -EINVAL; + + + if (CHK_FLAGS(status, SOLO_IIC_STATE_TRNS | SOLO_IIC_STATE_SIG_ERR) + || solo_dev->i2c_id < 0) { + solo_i2c_stop(solo_dev); + return -ENXIO; + } + + switch (solo_dev->i2c_state) { + case IIC_STATE_START: + if (solo_dev->i2c_msg->flags & I2C_M_RD) { + solo_dev->i2c_state = IIC_STATE_READ; + ret = solo_i2c_handle_read(solo_dev); + break; + } + + solo_dev->i2c_state = IIC_STATE_WRITE; + case IIC_STATE_WRITE: + ret = solo_i2c_handle_write(solo_dev); + break; + + case IIC_STATE_READ: + solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr] = + solo_reg_read(solo_dev, SOLO_IIC_RXD); + solo_dev->i2c_msg_ptr++; + + ret = solo_i2c_handle_read(solo_dev); + break; + + default: + solo_i2c_stop(solo_dev); + } + + return ret; +} + +static int solo_i2c_master_xfer(struct i2c_adapter *adap, + struct i2c_msg msgs[], int num) +{ + struct solo_dev *solo_dev = adap->algo_data; + unsigned long timeout; + int ret; + int i; + DEFINE_WAIT(wait); + + for (i = 0; i < SOLO_I2C_ADAPTERS; i++) { + if (&solo_dev->i2c_adap[i] == adap) + break; + } + + if (i == SOLO_I2C_ADAPTERS) + return num; /* XXX Right return value for failure? */ + + mutex_lock(&solo_dev->i2c_mutex); + solo_dev->i2c_id = i; + solo_dev->i2c_msg = msgs; + solo_dev->i2c_msg_num = num; + solo_dev->i2c_msg_ptr = 0; + + solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0); + solo_irq_on(solo_dev, SOLO_IRQ_IIC); + solo_i2c_start(solo_dev); + + timeout = HZ / 2; + + for (;;) { + prepare_to_wait(&solo_dev->i2c_wait, &wait, + TASK_INTERRUPTIBLE); + + if (solo_dev->i2c_state == IIC_STATE_STOP) + break; + + timeout = schedule_timeout(timeout); + if (!timeout) + break; + + if (signal_pending(current)) + break; + } + + finish_wait(&solo_dev->i2c_wait, &wait); + ret = num - solo_dev->i2c_msg_num; + solo_dev->i2c_state = IIC_STATE_IDLE; + solo_dev->i2c_id = -1; + + mutex_unlock(&solo_dev->i2c_mutex); + + return ret; +} + +static u32 solo_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C; +} + +static const struct i2c_algorithm solo_i2c_algo = { + .master_xfer = solo_i2c_master_xfer, + .functionality = solo_i2c_functionality, +}; + +int solo_i2c_init(struct solo_dev *solo_dev) +{ + int i; + int ret; + + solo_reg_write(solo_dev, SOLO_IIC_CFG, + SOLO_IIC_PRESCALE(8) | SOLO_IIC_ENABLE); + + solo_dev->i2c_id = -1; + solo_dev->i2c_state = IIC_STATE_IDLE; + init_waitqueue_head(&solo_dev->i2c_wait); + mutex_init(&solo_dev->i2c_mutex); + + for (i = 0; i < SOLO_I2C_ADAPTERS; i++) { + struct i2c_adapter *adap = &solo_dev->i2c_adap[i]; + + snprintf(adap->name, I2C_NAME_SIZE, "%s I2C %d", + SOLO6X10_NAME, i); + adap->algo = &solo_i2c_algo; + adap->algo_data = solo_dev; + adap->retries = 1; + adap->dev.parent = &solo_dev->pdev->dev; + + ret = i2c_add_adapter(adap); + if (ret) { + adap->algo_data = NULL; + break; + } + } + + if (ret) { + for (i = 0; i < SOLO_I2C_ADAPTERS; i++) { + if (!solo_dev->i2c_adap[i].algo_data) + break; + i2c_del_adapter(&solo_dev->i2c_adap[i]); + solo_dev->i2c_adap[i].algo_data = NULL; + } + return ret; + } + + return 0; +} + +void solo_i2c_exit(struct solo_dev *solo_dev) +{ + int i; + + for (i = 0; i < SOLO_I2C_ADAPTERS; i++) { + if (!solo_dev->i2c_adap[i].algo_data) + continue; + i2c_del_adapter(&solo_dev->i2c_adap[i]); + solo_dev->i2c_adap[i].algo_data = NULL; + } +} |