Markus Rechberger <mrechberger@gmail.com>
Mauro Carvalho Chehab <mchehab@infradead.org>
Sascha Sommer <saschasommer@freenet.de>
+ Copyright (C) 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
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
return (ret < 0) ? ret : -EIO;
}
+/*
+ * em25xx_bus_B_send_bytes
+ * write bytes to the i2c device
+ */
+static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
+ u16 len)
+{
+ int ret;
+
+ if (len < 1 || len > 64)
+ return -EOPNOTSUPP;
+ /*
+ * NOTE: limited by the USB ctrl message constraints
+ * Zero length reads always succeed, even if no device is connected
+ */
+
+ /* Set register and write value */
+ ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
+ if (ret != len) {
+ if (ret < 0) {
+ em28xx_warn("writing to i2c device at 0x%x failed (error=%i)\n",
+ addr, ret);
+ return ret;
+ } else {
+ em28xx_warn("%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
+ len, addr, ret);
+ return -EIO;
+ }
+ }
+ /* Check success */
+ ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
+ /*
+ * NOTE: the only error we've seen so far is
+ * 0x01 when the slave device is not present
+ */
+ if (!ret)
+ return len;
+ else if (ret > 0)
+ return -ENODEV;
+
+ return ret;
+ /*
+ * NOTE: With chip types (other chip IDs) which actually don't support
+ * this operation, it seems to succeed ALWAYS ! (even if there is no
+ * slave device or even no second i2c bus provided)
+ */
+}
+
+/*
+ * em25xx_bus_B_recv_bytes
+ * read bytes from the i2c device
+ */
+static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
+ u16 len)
+{
+ int ret;
+
+ if (len < 1 || len > 64)
+ return -EOPNOTSUPP;
+ /*
+ * NOTE: limited by the USB ctrl message constraints
+ * Zero length reads always succeed, even if no device is connected
+ */
+
+ /* Read value */
+ ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
+ if (ret < 0) {
+ em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
+ addr, ret);
+ return ret;
+ }
+ /*
+ * NOTE: some devices with two i2c busses have the bad habit to return 0
+ * bytes if we are on bus B AND there was no write attempt to the
+ * specified slave address before AND no device is present at the
+ * requested slave address.
+ * Anyway, the next check will fail with -ENODEV in this case, so avoid
+ * spamming the system log on device probing and do nothing here.
+ */
+
+ /* Check success */
+ ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
+ /*
+ * NOTE: the only error we've seen so far is
+ * 0x01 when the slave device is not present
+ */
+ if (!ret)
+ return len;
+ else if (ret > 0)
+ return -ENODEV;
+
+ return ret;
+ /*
+ * NOTE: With chip types (other chip IDs) which actually don't support
+ * this operation, it seems to succeed ALWAYS ! (even if there is no
+ * slave device or even no second i2c bus provided)
+ */
+}
+
+/*
+ * em25xx_bus_B_check_for_device()
+ * check if there is a i2c device at the supplied address
+ */
+static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
+{
+ u8 buf;
+ int ret;
+
+ ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+ /*
+ * NOTE: With chips which do not support this operation,
+ * it seems to succeed ALWAYS ! (even if no device connected)
+ */
+}
+
+static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
+{
+ struct em28xx *dev = i2c_bus->dev;
+ int rc = -EOPNOTSUPP;
+
+ if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+ rc = em28xx_i2c_check_for_device(dev, addr);
+ else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+ rc = em2800_i2c_check_for_device(dev, addr);
+ else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+ rc = em25xx_bus_B_check_for_device(dev, addr);
+ if (rc == -ENODEV) {
+ if (i2c_debug)
+ printk(" no device\n");
+ }
+ return rc;
+}
+
+static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
+ struct i2c_msg msg)
+{
+ struct em28xx *dev = i2c_bus->dev;
+ u16 addr = msg.addr << 1;
+ int byte, rc = -EOPNOTSUPP;
+
+ if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+ rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
+ else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+ rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
+ else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+ rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
+ if (i2c_debug) {
+ for (byte = 0; byte < msg.len; byte++)
+ printk(" %02x", msg.buf[byte]);
+ }
+ return rc;
+}
+
+static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
+ struct i2c_msg msg, int stop)
+{
+ struct em28xx *dev = i2c_bus->dev;
+ u16 addr = msg.addr << 1;
+ int byte, rc = -EOPNOTSUPP;
+
+ if (i2c_debug) {
+ for (byte = 0; byte < msg.len; byte++)
+ printk(" %02x", msg.buf[byte]);
+ }
+ if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+ rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
+ else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+ rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
+ else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+ rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
+ return rc;
+}
+
/*
* em28xx_i2c_xfer()
* the main i2c transfer function
struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
struct em28xx *dev = i2c_bus->dev;
unsigned bus = i2c_bus->bus;
- int addr, rc, i, byte;
+ int addr, rc, i;
u8 reg;
rc = rt_mutex_trylock(&dev->i2c_bus_lock);
return rc;
/* Switch I2C bus if needed */
- if (bus != dev->cur_i2c_bus) {
+ if (bus != dev->cur_i2c_bus &&
+ i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
if (bus == 1)
reg = EM2874_I2C_SECONDARY_BUS_SELECT;
else
i == num - 1 ? "stop" : "nonstop",
addr, msgs[i].len);
if (!msgs[i].len) { /* no len: check only for device presence */
- if (dev->board.is_em2800)
- rc = em2800_i2c_check_for_device(dev, addr);
- else
- rc = em28xx_i2c_check_for_device(dev, addr);
+ rc = i2c_check_for_device(i2c_bus, addr);
if (rc == -ENODEV) {
- if (i2c_debug)
- printk(" no device\n");
rt_mutex_unlock(&dev->i2c_bus_lock);
return rc;
}
} else if (msgs[i].flags & I2C_M_RD) {
/* read bytes */
- if (dev->board.is_em2800)
- rc = em2800_i2c_recv_bytes(dev, addr,
- msgs[i].buf,
- msgs[i].len);
- else
- rc = em28xx_i2c_recv_bytes(dev, addr,
- msgs[i].buf,
- msgs[i].len);
- if (i2c_debug) {
- for (byte = 0; byte < msgs[i].len; byte++)
- printk(" %02x", msgs[i].buf[byte]);
- }
+ rc = i2c_recv_bytes(i2c_bus, msgs[i]);
} else {
/* write bytes */
- if (i2c_debug) {
- for (byte = 0; byte < msgs[i].len; byte++)
- printk(" %02x", msgs[i].buf[byte]);
- }
- if (dev->board.is_em2800)
- rc = em2800_i2c_send_bytes(dev, addr,
- msgs[i].buf,
- msgs[i].len);
- else
- rc = em28xx_i2c_send_bytes(dev, addr,
- msgs[i].buf,
- msgs[i].len,
- i == num - 1);
+ rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
}
if (rc < 0) {
if (i2c_debug)
static u32 functionality(struct i2c_adapter *i2c_adap)
{
struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
- struct em28xx *dev = i2c_bus->dev;
- u32 func_flags = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
- if (dev->board.is_em2800)
- func_flags &= ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
- return func_flags;
+ if ((i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) ||
+ (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)) {
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+ } else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800) {
+ return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
+ ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
+ }
+
+ WARN(1, "Unknown i2c bus algorithm.\n");
+ return 0;
}
static struct i2c_algorithm em28xx_algo = {
* em28xx_i2c_register()
* register i2c bus
*/
-int em28xx_i2c_register(struct em28xx *dev, unsigned bus)
+int em28xx_i2c_register(struct em28xx *dev, unsigned bus,
+ enum em28xx_i2c_algo_type algo_type)
{
int retval;
strcpy(dev->i2c_adap[bus].name, dev->name);
dev->i2c_bus[bus].bus = bus;
+ dev->i2c_bus[bus].algo_type = algo_type;
dev->i2c_bus[bus].dev = dev;
dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
i2c_set_adapdata(&dev->i2c_adap[bus], &dev->v4l2_dev);
projects / linux.git / commitdiff