diff options
author | Simon Glass <sjg@chromium.org> | 2015-07-03 00:15:47 (GMT) |
---|---|---|
committer | Simon Glass <sjg@chromium.org> | 2015-08-06 03:06:10 (GMT) |
commit | 45d9ae87cbe9b2e76a856647c35da83535af2984 (patch) | |
tree | 16d28eb57196235359850f6a542ea5b9b69fdbcf /drivers | |
parent | 26ea76850e136651d0b02f6623b5c39fb98b10eb (diff) | |
download | u-boot-45d9ae87cbe9b2e76a856647c35da83535af2984.tar.xz |
exynos: i2c: Tidy up the driver model code
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@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/i2c/s3c24x0_i2c.c | 139 |
1 files 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@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 */ |