diff options
Diffstat (limited to 'drivers/media/pci/cx25821/cx25821-i2c.c')
-rw-r--r-- | drivers/media/pci/cx25821/cx25821-i2c.c | 415 |
1 files changed, 415 insertions, 0 deletions
diff --git a/drivers/media/pci/cx25821/cx25821-i2c.c b/drivers/media/pci/cx25821/cx25821-i2c.c new file mode 100644 index 000000000..31479a41f --- /dev/null +++ b/drivers/media/pci/cx25821/cx25821-i2c.c @@ -0,0 +1,415 @@ +/* + * Driver for the Conexant CX25821 PCIe bridge + * + * Copyright (C) 2009 Conexant Systems Inc. + * Authors <shu.lin@conexant.com>, <hiep.huynh@conexant.com> + * Based on Steven Toth <stoth@linuxtv.org> cx23885 driver + * + * 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/i2c.h> +#include "cx25821.h" + +static unsigned int i2c_debug; +module_param(i2c_debug, int, 0644); +MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]"); + +static unsigned int i2c_scan; +module_param(i2c_scan, int, 0444); +MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time"); + +#define dprintk(level, fmt, arg...) \ +do { \ + if (i2c_debug >= level) \ + printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg); \ +} while (0) + +#define I2C_WAIT_DELAY 32 +#define I2C_WAIT_RETRY 64 + +#define I2C_EXTEND (1 << 3) +#define I2C_NOSTOP (1 << 4) + +static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap) +{ + struct cx25821_i2c *bus = i2c_adap->algo_data; + struct cx25821_dev *dev = bus->dev; + return cx_read(bus->reg_stat) & 0x01; +} + +static inline int i2c_is_busy(struct i2c_adapter *i2c_adap) +{ + struct cx25821_i2c *bus = i2c_adap->algo_data; + struct cx25821_dev *dev = bus->dev; + return cx_read(bus->reg_stat) & 0x02 ? 1 : 0; +} + +static int i2c_wait_done(struct i2c_adapter *i2c_adap) +{ + int count; + + for (count = 0; count < I2C_WAIT_RETRY; count++) { + if (!i2c_is_busy(i2c_adap)) + break; + udelay(I2C_WAIT_DELAY); + } + + if (I2C_WAIT_RETRY == count) + return 0; + + return 1; +} + +static int i2c_sendbytes(struct i2c_adapter *i2c_adap, + const struct i2c_msg *msg, int joined_rlen) +{ + struct cx25821_i2c *bus = i2c_adap->algo_data; + struct cx25821_dev *dev = bus->dev; + u32 wdata, addr, ctrl; + int retval, cnt; + + if (joined_rlen) + dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__, + msg->len, joined_rlen); + else + dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len); + + /* Deal with i2c probe functions with zero payload */ + if (msg->len == 0) { + cx_write(bus->reg_addr, msg->addr << 25); + cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2)); + + if (!i2c_wait_done(i2c_adap)) + return -EIO; + + if (!i2c_slave_did_ack(i2c_adap)) + return -EIO; + + dprintk(1, "%s(): returns 0\n", __func__); + return 0; + } + + /* dev, reg + first byte */ + addr = (msg->addr << 25) | msg->buf[0]; + wdata = msg->buf[0]; + + ctrl = bus->i2c_period | (1 << 12) | (1 << 2); + + if (msg->len > 1) + ctrl |= I2C_NOSTOP | I2C_EXTEND; + else if (joined_rlen) + ctrl |= I2C_NOSTOP; + + cx_write(bus->reg_addr, addr); + cx_write(bus->reg_wdata, wdata); + cx_write(bus->reg_ctrl, ctrl); + + retval = i2c_wait_done(i2c_adap); + if (retval < 0) + goto err; + + if (retval == 0) + goto eio; + + if (i2c_debug) { + if (!(ctrl & I2C_NOSTOP)) + printk(" >\n"); + } + + for (cnt = 1; cnt < msg->len; cnt++) { + /* following bytes */ + wdata = msg->buf[cnt]; + ctrl = bus->i2c_period | (1 << 12) | (1 << 2); + + if (cnt < msg->len - 1) + ctrl |= I2C_NOSTOP | I2C_EXTEND; + else if (joined_rlen) + ctrl |= I2C_NOSTOP; + + cx_write(bus->reg_addr, addr); + cx_write(bus->reg_wdata, wdata); + cx_write(bus->reg_ctrl, ctrl); + + retval = i2c_wait_done(i2c_adap); + if (retval < 0) + goto err; + + if (retval == 0) + goto eio; + + if (i2c_debug) { + dprintk(1, " %02x", msg->buf[cnt]); + if (!(ctrl & I2C_NOSTOP)) + dprintk(1, " >\n"); + } + } + + return msg->len; + +eio: + retval = -EIO; +err: + if (i2c_debug) + pr_err(" ERR: %d\n", retval); + return retval; +} + +static int i2c_readbytes(struct i2c_adapter *i2c_adap, + const struct i2c_msg *msg, int joined) +{ + struct cx25821_i2c *bus = i2c_adap->algo_data; + struct cx25821_dev *dev = bus->dev; + u32 ctrl, cnt; + int retval; + + if (i2c_debug && !joined) + dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len); + + /* Deal with i2c probe functions with zero payload */ + if (msg->len == 0) { + cx_write(bus->reg_addr, msg->addr << 25); + cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1); + if (!i2c_wait_done(i2c_adap)) + return -EIO; + if (!i2c_slave_did_ack(i2c_adap)) + return -EIO; + + dprintk(1, "%s(): returns 0\n", __func__); + return 0; + } + + if (i2c_debug) { + if (joined) + dprintk(1, " R"); + else + dprintk(1, " <R %02x", (msg->addr << 1) + 1); + } + + for (cnt = 0; cnt < msg->len; cnt++) { + + ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1; + + if (cnt < msg->len - 1) + ctrl |= I2C_NOSTOP | I2C_EXTEND; + + cx_write(bus->reg_addr, msg->addr << 25); + cx_write(bus->reg_ctrl, ctrl); + + retval = i2c_wait_done(i2c_adap); + if (retval < 0) + goto err; + if (retval == 0) + goto eio; + msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff; + + if (i2c_debug) { + dprintk(1, " %02x", msg->buf[cnt]); + if (!(ctrl & I2C_NOSTOP)) + dprintk(1, " >\n"); + } + } + + return msg->len; +eio: + retval = -EIO; +err: + if (i2c_debug) + pr_err(" ERR: %d\n", retval); + return retval; +} + +static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) +{ + struct cx25821_i2c *bus = i2c_adap->algo_data; + struct cx25821_dev *dev = bus->dev; + int i, retval = 0; + + dprintk(1, "%s(num = %d)\n", __func__, num); + + for (i = 0; i < num; i++) { + dprintk(1, "%s(num = %d) addr = 0x%02x len = 0x%x\n", + __func__, num, msgs[i].addr, msgs[i].len); + + if (msgs[i].flags & I2C_M_RD) { + /* read */ + retval = i2c_readbytes(i2c_adap, &msgs[i], 0); + } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) && + msgs[i].addr == msgs[i + 1].addr) { + /* write then read from same address */ + retval = i2c_sendbytes(i2c_adap, &msgs[i], + msgs[i + 1].len); + + if (retval < 0) + goto err; + i++; + retval = i2c_readbytes(i2c_adap, &msgs[i], 1); + } else { + /* write */ + retval = i2c_sendbytes(i2c_adap, &msgs[i], 0); + } + + if (retval < 0) + goto err; + } + return num; + +err: + return retval; +} + + +static u32 cx25821_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA; +} + +static const struct i2c_algorithm cx25821_i2c_algo_template = { + .master_xfer = i2c_xfer, + .functionality = cx25821_functionality, +#ifdef NEED_ALGO_CONTROL + .algo_control = dummy_algo_control, +#endif +}; + +static const struct i2c_adapter cx25821_i2c_adap_template = { + .name = "cx25821", + .owner = THIS_MODULE, + .algo = &cx25821_i2c_algo_template, +}; + +static const struct i2c_client cx25821_i2c_client_template = { + .name = "cx25821 internal", +}; + +/* init + register i2c adapter */ +int cx25821_i2c_register(struct cx25821_i2c *bus) +{ + struct cx25821_dev *dev = bus->dev; + + dprintk(1, "%s(bus = %d)\n", __func__, bus->nr); + + bus->i2c_adap = cx25821_i2c_adap_template; + bus->i2c_client = cx25821_i2c_client_template; + bus->i2c_adap.dev.parent = &dev->pci->dev; + + strlcpy(bus->i2c_adap.name, bus->dev->name, sizeof(bus->i2c_adap.name)); + + bus->i2c_adap.algo_data = bus; + i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev); + i2c_add_adapter(&bus->i2c_adap); + + bus->i2c_client.adapter = &bus->i2c_adap; + + /* set up the I2c */ + bus->i2c_client.addr = (0x88 >> 1); + + return bus->i2c_rc; +} + +int cx25821_i2c_unregister(struct cx25821_i2c *bus) +{ + i2c_del_adapter(&bus->i2c_adap); + return 0; +} + +#if 0 /* Currently unused */ +static void cx25821_av_clk(struct cx25821_dev *dev, int enable) +{ + /* write 0 to bus 2 addr 0x144 via i2x_xfer() */ + char buffer[3]; + struct i2c_msg msg; + dprintk(1, "%s(enabled = %d)\n", __func__, enable); + + /* Register 0x144 */ + buffer[0] = 0x01; + buffer[1] = 0x44; + if (enable == 1) + buffer[2] = 0x05; + else + buffer[2] = 0x00; + + msg.addr = 0x44; + msg.flags = I2C_M_TEN; + msg.len = 3; + msg.buf = buffer; + + i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1); +} +#endif + +int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value) +{ + struct i2c_client *client = &bus->i2c_client; + int v = 0; + u8 addr[2] = { 0, 0 }; + u8 buf[4] = { 0, 0, 0, 0 }; + + struct i2c_msg msgs[2] = { + { + .addr = client->addr, + .flags = 0, + .len = 2, + .buf = addr, + }, { + .addr = client->addr, + .flags = I2C_M_RD, + .len = 4, + .buf = buf, + } + }; + + addr[0] = (reg_addr >> 8); + addr[1] = (reg_addr & 0xff); + msgs[0].addr = 0x44; + msgs[1].addr = 0x44; + + i2c_xfer(client->adapter, msgs, 2); + + v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; + *value = v; + + return v; +} + +int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value) +{ + struct i2c_client *client = &bus->i2c_client; + int retval = 0; + u8 buf[6] = { 0, 0, 0, 0, 0, 0 }; + + struct i2c_msg msgs[1] = { + { + .addr = client->addr, + .flags = 0, + .len = 6, + .buf = buf, + } + }; + + buf[0] = reg_addr >> 8; + buf[1] = reg_addr & 0xff; + buf[5] = (value >> 24) & 0xff; + buf[4] = (value >> 16) & 0xff; + buf[3] = (value >> 8) & 0xff; + buf[2] = value & 0xff; + client->flags = 0; + msgs[0].addr = 0x44; + + retval = i2c_xfer(client->adapter, msgs, 1); + + return retval; +} |