Hi Simon,
My review is still under way,
but I have some comments below:
On Mon, 24 Nov 2014 11:57:15 -0700
Simon Glass <s...@chromium.org> wrote:
+static bool i2c_setup_offset(struct dm_i2c_chip *chip, uint offset,
+ uint8_t offset_buf[], struct i2c_msg *msg)
+{
+ if (!chip->offset_len)
+ return false;
+ msg->addr = chip->chip_addr;
+ msg->flags = chip->flags;
+ msg->len = chip->offset_len;
+ msg->buf = offset_buf;
You directly copy
from (struct dm_i2c_chip *)->flags
to (struct i2c_msg *)->flags.
But you define completely different flags for them:
DM_I2C_CHIP_10BIT is defined as 0x1.
I2C_M_TEN is defined as 0x10.
It would not work.
+
+static int i2c_read_bytewise(struct udevice *dev, uint offset,
+ const uint8_t *buffer, int len)
+{
+ struct dm_i2c_chip *chip = dev_get_parentdata(dev);
+ struct udevice *bus = dev_get_parent(dev);
+ struct dm_i2c_ops *ops = i2c_get_ops(bus);
+ struct i2c_msg msg[1];
+ uint8_t buf[5];
+ int ret;
+ int i;
+
+ for (i = 0; i < len; i++) {
+ i2c_setup_offset(chip, offset, buf, msg);
+ msg->len++;
+ buf[chip->offset_len] = buffer[i];
+
+ ret = ops->xfer(bus, msg, 1);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
I could not understand how this works.
It seems to send only write transactions.
+
+static int i2c_bind_driver(struct udevice *bus, uint chip_addr,
+ struct udevice **devp)
+{
+ struct dm_i2c_chip *chip;
+ char name[30], *str;
+ struct udevice *dev;
+ int ret;
+
+ snprintf(name, sizeof(name), "generic_%x", chip_addr);
+ str = strdup(name);
+ ret = device_bind_driver(bus, "i2c_generic_drv", str, &dev);
+ debug("%s: device_bind_driver: ret=%d\n", __func__, ret);
+ if (ret)
+ goto err_bind;
+
+ /* Tell the device what we know about it */
+ chip = calloc(1, sizeof(struct dm_i2c_chip));
+ if (!chip) {
+ ret = -ENOMEM;
+ goto err_mem;
+ }
+ chip->chip_addr = chip_addr;
+ chip->offset_len = 1; /* we assume */
+ ret = device_probe_child(dev, chip);
+ debug("%s: device_probe_child: ret=%d\n", __func__, ret);
+ free(chip);
Why do you need calloc() & free() here?
I think you can use the stack area for "struct dm_i2c_chip chip;"
+
+UCLASS_DRIVER(i2c) = {
+ .id = UCLASS_I2C,
+ .name = "i2c",
+ .per_device_auto_alloc_size = sizeof(struct dm_i2c_bus),
+ .post_bind = i2c_post_bind,
+ .post_probe = i2c_post_probe,
+};
+
+UCLASS_DRIVER(i2c_generic) = {
+ .id = UCLASS_I2C_GENERIC,
+ .name = "i2c_generic",
+};
+
+U_BOOT_DRIVER(i2c_generic_drv) = {
Perhaps isn't "i2c_generic_chip" clearer than "i2c_generic_drv"?
+ .name = "i2c_generic_drv",
+ .id = UCLASS_I2C_GENERIC,
+};
Can we move "i2c_generic" to a different file?
maybe, drivers/i2c/i2c-generic.c or drivers/i2c/i2c-generic-chip.c ?
UCLASS_DRIVER(i2c) is a bus, whereas UCLASS_DRIVER(i2c_generic) is a chip.
Mixing up a bus and a chip-device together in the same file
looks confusing to me.
/*
+ * For now there are essentially two parts to this file - driver model
+ * here at the top, and the older code below (with CONFIG_SYS_I2C being
+ * most recent). The plan is to migrate everything to driver model.
+ * The driver model structures and API are separate as they are different
+ * enough as to be incompatible for compilation purposes.
+ */
+
+#ifdef CONFIG_DM_I2C
+
+enum dm_i2c_chip_flags {
+ DM_I2C_CHIP_10BIT = 1 << 0, /* Use 10-bit addressing */
+ DM_I2C_CHIP_RE_ADDRESS = 1 << 1, /* Send address for every byte */
+};
As I mentioned above, you define DM_I2C_CHIP_10BIT as 0x1
whereas you define I2C_M_TEN as 0x0010.
These flags should be shared with struct i2c_msg.
+/*
+ * Not all of these flags are implemented in the U-Boot API
+ */
+enum dm_i2c_msg_flags {
+ I2C_M_TEN = 0x0010, /* ten-bit chip address */
+ I2C_M_RD = 0x0001, /* read data, from slave to master */
+ I2C_M_STOP = 0x8000, /* send stop after this message */
+ I2C_M_NOSTART = 0x4000, /* no start before this message */
+ I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
+ I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
+ I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
+ I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
+};
I think this enum usage is odd.
If you want to allocate specific values such as 0x8000, 0x4000, etc.
you should use #define instead of enum.
If you do not care which value is assigned, you can use enum.
arch/arm/include/asm/spl.h is a good example of usage of enum.
+};
+
+/**
+ * struct dm_i2c_ops - driver operations for I2C uclass
+ *
+ * Drivers should support these operations unless otherwise noted. These
+ * operations are intended to be used by uclass code, not directly from
+ * other code.
+ */
+struct dm_i2c_ops {
+ /**
+ * xfer() - transfer a list of I2C messages
+ *
+ * @bus: Bus to read from
+ * @chip_addr: Chip address to read from
+ * @offset: Offset within chip to start reading
+ * @olen: Length of chip offset in bytes
+ * @buffer: Place to put data
+ * @len: Number of bytes to read
+ * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
+ * other -ve value on some other error
+ */
+ int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
This comment block does not reflect the actual prototype;
chip_addr, offset, ... etc. do not exist any more.
