[U-Boot] [PATCH 10/55] exynos: i2c: Tidy up the driver model code
Simon Glass
sjg at chromium.org
Fri Jul 3 02:15:47 CEST 2015
The existing driver model implementation uses the old non-driver-model code
to operate, but has become impossibly tangled as a result. The actual
algorithm is quite simple.
Also the normal-speed and high-speed buses are quite different and it
doesn't seem that useful to put them in the same driver.
Finally, there is a bug which breaks communication with the Maxim sound
codec and may cause problems with other device.
Rewrite the driver model code for normal-speed operation so that it is
easier to understand, and fix the bug. Add a TODO to split the drivers.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
drivers/i2c/s3c24x0_i2c.c | 139 ++++++++++++++++++++++++++++++++++------------
1 file changed, 103 insertions(+), 36 deletions(-)
diff --git a/drivers/i2c/s3c24x0_i2c.c b/drivers/i2c/s3c24x0_i2c.c
index 4bbd012..c11a6be 100644
--- a/drivers/i2c/s3c24x0_i2c.c
+++ b/drivers/i2c/s3c24x0_i2c.c
@@ -1284,62 +1284,106 @@ U_BOOT_I2C_ADAP_COMPLETE(s3c0, s3c24x0_i2c_init, s3c24x0_i2c_probe,
#endif /* CONFIG_SYS_I2C */
#ifdef CONFIG_DM_I2C
-static int i2c_write_data(struct s3c24x0_i2c_bus *i2c_bus, uchar chip,
- uchar *buffer, int len, bool end_with_repeated_start)
+static int exynos_hs_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
+ int nmsgs)
{
+ struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
+ struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
int ret;
- if (i2c_bus->is_highspeed) {
- ret = hsi2c_write(i2c_bus->hsregs, chip, 0, 0,
- buffer, len, true);
- if (ret)
+ for (; nmsgs > 0; nmsgs--, msg++) {
+ if (msg->flags & I2C_M_RD) {
+ ret = hsi2c_read(hsregs, msg->addr, 0, 0, msg->buf,
+ msg->len);
+ } else {
+ ret = hsi2c_write(hsregs, msg->addr, 0, 0, msg->buf,
+ msg->len, true);
+ }
+ if (ret) {
exynos5_i2c_reset(i2c_bus);
- } else {
- ret = i2c_transfer(i2c_bus->regs, I2C_WRITE,
- chip << 1, 0, 0, buffer, len);
+ return -EREMOTEIO;
+ }
}
- return ret != I2C_OK;
+ return 0;
}
-static int i2c_read_data(struct s3c24x0_i2c_bus *i2c_bus, uchar chip,
- uchar *buffer, int len)
+static int s3c24x0_do_msg(struct s3c24x0_i2c_bus *i2c_bus, struct i2c_msg *msg,
+ int seq)
{
- int ret;
+ struct s3c24x0_i2c *i2c = i2c_bus->regs;
+ bool is_read = msg->flags & I2C_M_RD;
+ uint status;
+ uint addr;
+ int ret, i;
- if (i2c_bus->is_highspeed) {
- ret = hsi2c_read(i2c_bus->hsregs, chip, 0, 0, buffer, len);
- if (ret)
- exynos5_i2c_reset(i2c_bus);
+ if (!seq)
+ setbits_le32(&i2c->iiccon, I2CCON_ACKGEN);
+
+ /* Get the slave chip address going */
+ addr = msg->addr << 1;
+ writel(addr, &i2c->iicds);
+ status = I2C_TXRX_ENA | I2C_START_STOP;
+ if (is_read)
+ status |= I2C_MODE_MR;
+ else
+ status |= I2C_MODE_MT;
+ writel(status, &i2c->iicstat);
+ if (seq)
+ read_write_byte(i2c);
+
+ /* Wait for chip address to transmit */
+ ret = WaitForXfer(i2c);
+ if (ret)
+ goto err;
+
+ if (is_read) {
+ for (i = 0; !ret && i < msg->len; i++) {
+ /* disable ACK for final READ */
+ if (i == msg->len - 1)
+ clrbits_le32(&i2c->iiccon, I2CCON_ACKGEN);
+ read_write_byte(i2c);
+ ret = WaitForXfer(i2c);
+ msg->buf[i] = readl(&i2c->iicds);
+ }
+ if (ret == I2C_NACK)
+ ret = I2C_OK; /* Normal terminated read */
} else {
- ret = i2c_transfer(i2c_bus->regs, I2C_READ,
- chip << 1, 0, 0, buffer, len);
+ for (i = 0; !ret && i < msg->len; i++) {
+ writel(msg->buf[i], &i2c->iicds);
+ read_write_byte(i2c);
+ ret = WaitForXfer(i2c);
+ }
}
- return ret != I2C_OK;
+err:
+ return ret;
}
static int s3c24x0_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
int nmsgs)
{
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
- int ret;
+ struct s3c24x0_i2c *i2c = i2c_bus->regs;
+ ulong start_time;
+ int ret, i;
- for (; nmsgs > 0; nmsgs--, msg++) {
- bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);
-
- if (msg->flags & I2C_M_RD) {
- ret = i2c_read_data(i2c_bus, msg->addr, msg->buf,
- msg->len);
- } else {
- ret = i2c_write_data(i2c_bus, msg->addr, msg->buf,
- msg->len, next_is_read);
+ start_time = get_timer(0);
+ while (readl(&i2c->iicstat) & I2CSTAT_BSY) {
+ if (get_timer(start_time) > I2C_TIMEOUT_MS) {
+ debug("Timeout\n");
+ return -ETIMEDOUT;
}
- if (ret)
- return -EREMOTEIO;
}
- return 0;
+ for (ret = 0, i = 0; !ret && i < nmsgs; i++)
+ ret = s3c24x0_do_msg(i2c_bus, &msg[i], i);
+
+ /* Send STOP */
+ writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
+ read_write_byte(i2c);
+
+ return ret ? -EREMOTEIO : 0;
}
static int s3c_i2c_ofdata_to_platdata(struct udevice *dev)
@@ -1364,8 +1408,7 @@ static int s3c_i2c_ofdata_to_platdata(struct udevice *dev)
i2c_bus->id = pinmux_decode_periph_id(blob, node);
i2c_bus->clock_frequency = fdtdec_get_int(blob, node,
- "clock-frequency",
- CONFIG_SYS_I2C_S3C24X0_SPEED);
+ "clock-frequency", 100000);
i2c_bus->node = node;
i2c_bus->bus_num = dev->seq;
@@ -1384,7 +1427,6 @@ static const struct dm_i2c_ops s3c_i2c_ops = {
static const struct udevice_id s3c_i2c_ids[] = {
{ .compatible = "samsung,s3c2440-i2c", .data = EXYNOS_I2C_STD },
- { .compatible = "samsung,exynos5-hsi2c", .data = EXYNOS_I2C_HS },
{ }
};
@@ -1397,4 +1439,29 @@ U_BOOT_DRIVER(i2c_s3c) = {
.priv_auto_alloc_size = sizeof(struct s3c24x0_i2c_bus),
.ops = &s3c_i2c_ops,
};
+
+/*
+ * TODO(sjg at chromium.org): Move this to a separate file when everything uses
+ * driver model
+ */
+static const struct dm_i2c_ops exynos_hs_i2c_ops = {
+ .xfer = exynos_hs_i2c_xfer,
+ .probe_chip = s3c24x0_i2c_probe,
+ .set_bus_speed = s3c24x0_i2c_set_bus_speed,
+};
+
+static const struct udevice_id exynos_hs_i2c_ids[] = {
+ { .compatible = "samsung,exynos5-hsi2c", .data = EXYNOS_I2C_HS },
+ { }
+};
+
+U_BOOT_DRIVER(hs_i2c) = {
+ .name = "i2c_s3c_hs",
+ .id = UCLASS_I2C,
+ .of_match = exynos_hs_i2c_ids,
+ .ofdata_to_platdata = s3c_i2c_ofdata_to_platdata,
+ .per_child_auto_alloc_size = sizeof(struct dm_i2c_chip),
+ .priv_auto_alloc_size = sizeof(struct s3c24x0_i2c_bus),
+ .ops = &exynos_hs_i2c_ops,
+};
#endif /* CONFIG_DM_I2C */
--
2.4.3.573.g4eafbef
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