drm/i2c: tda998x: check more I/O errors

This patch adds more error checking inn I2C I/O functions.
In case of I/O error, this permits to avoid writing in bad controller
pages, a bad chipset detection or looping when getting the EDID.

Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Jean-Francois Moine 2014-01-25 18:14:45 +01:00 committed by Russell King
parent 2f7f730a4f
commit 7d2eadc9b9
1 changed files with 43 additions and 14 deletions

View File

@ -363,7 +363,7 @@ cec_read(struct tda998x_priv *priv, uint8_t addr)
return 0; return 0;
} }
static void static int
set_page(struct tda998x_priv *priv, uint16_t reg) set_page(struct tda998x_priv *priv, uint16_t reg)
{ {
if (REG2PAGE(reg) != priv->current_page) { if (REG2PAGE(reg) != priv->current_page) {
@ -372,11 +372,14 @@ set_page(struct tda998x_priv *priv, uint16_t reg)
REG_CURPAGE, REG2PAGE(reg) REG_CURPAGE, REG2PAGE(reg)
}; };
int ret = i2c_master_send(client, buf, sizeof(buf)); int ret = i2c_master_send(client, buf, sizeof(buf));
if (ret < 0) if (ret < 0) {
dev_err(&client->dev, "Error %d writing to REG_CURPAGE\n", ret); dev_err(&client->dev, "Error %d writing to REG_CURPAGE\n", ret);
return ret;
}
priv->current_page = REG2PAGE(reg); priv->current_page = REG2PAGE(reg);
} }
return 0;
} }
static int static int
@ -386,7 +389,9 @@ reg_read_range(struct tda998x_priv *priv, uint16_t reg, char *buf, int cnt)
uint8_t addr = REG2ADDR(reg); uint8_t addr = REG2ADDR(reg);
int ret; int ret;
set_page(priv, reg); ret = set_page(priv, reg);
if (ret < 0)
return ret;
ret = i2c_master_send(client, &addr, sizeof(addr)); ret = i2c_master_send(client, &addr, sizeof(addr));
if (ret < 0) if (ret < 0)
@ -413,18 +418,24 @@ reg_write_range(struct tda998x_priv *priv, uint16_t reg, uint8_t *p, int cnt)
buf[0] = REG2ADDR(reg); buf[0] = REG2ADDR(reg);
memcpy(&buf[1], p, cnt); memcpy(&buf[1], p, cnt);
set_page(priv, reg); ret = set_page(priv, reg);
if (ret < 0)
return;
ret = i2c_master_send(client, buf, cnt + 1); ret = i2c_master_send(client, buf, cnt + 1);
if (ret < 0) if (ret < 0)
dev_err(&client->dev, "Error %d writing to 0x%x\n", ret, reg); dev_err(&client->dev, "Error %d writing to 0x%x\n", ret, reg);
} }
static uint8_t static int
reg_read(struct tda998x_priv *priv, uint16_t reg) reg_read(struct tda998x_priv *priv, uint16_t reg)
{ {
uint8_t val = 0; uint8_t val = 0;
reg_read_range(priv, reg, &val, sizeof(val)); int ret;
ret = reg_read_range(priv, reg, &val, sizeof(val));
if (ret < 0)
return ret;
return val; return val;
} }
@ -435,7 +446,9 @@ reg_write(struct tda998x_priv *priv, uint16_t reg, uint8_t val)
uint8_t buf[] = {REG2ADDR(reg), val}; uint8_t buf[] = {REG2ADDR(reg), val};
int ret; int ret;
set_page(priv, reg); ret = set_page(priv, reg);
if (ret < 0)
return;
ret = i2c_master_send(client, buf, ARRAY_SIZE(buf)); ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
if (ret < 0) if (ret < 0)
@ -449,7 +462,9 @@ reg_write16(struct tda998x_priv *priv, uint16_t reg, uint16_t val)
uint8_t buf[] = {REG2ADDR(reg), val >> 8, val}; uint8_t buf[] = {REG2ADDR(reg), val >> 8, val};
int ret; int ret;
set_page(priv, reg); ret = set_page(priv, reg);
if (ret < 0)
return;
ret = i2c_master_send(client, buf, ARRAY_SIZE(buf)); ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
if (ret < 0) if (ret < 0)
@ -459,13 +474,21 @@ reg_write16(struct tda998x_priv *priv, uint16_t reg, uint16_t val)
static void static void
reg_set(struct tda998x_priv *priv, uint16_t reg, uint8_t val) reg_set(struct tda998x_priv *priv, uint16_t reg, uint8_t val)
{ {
reg_write(priv, reg, reg_read(priv, reg) | val); int old_val;
old_val = reg_read(priv, reg);
if (old_val >= 0)
reg_write(priv, reg, old_val | val);
} }
static void static void
reg_clear(struct tda998x_priv *priv, uint16_t reg, uint8_t val) reg_clear(struct tda998x_priv *priv, uint16_t reg, uint8_t val)
{ {
reg_write(priv, reg, reg_read(priv, reg) & ~val); int old_val;
old_val = reg_read(priv, reg);
if (old_val >= 0)
reg_write(priv, reg, old_val & ~val);
} }
static void static void
@ -978,8 +1001,10 @@ read_edid_block(struct drm_encoder *encoder, uint8_t *buf, int blk)
/* wait for block read to complete: */ /* wait for block read to complete: */
for (i = 100; i > 0; i--) { for (i = 100; i > 0; i--) {
uint8_t val = reg_read(priv, REG_INT_FLAGS_2); ret = reg_read(priv, REG_INT_FLAGS_2);
if (val & INT_FLAGS_2_EDID_BLK_RD) if (ret < 0)
return ret;
if (ret & INT_FLAGS_2_EDID_BLK_RD)
break; break;
msleep(1); msleep(1);
} }
@ -1144,6 +1169,7 @@ tda998x_encoder_init(struct i2c_client *client,
struct drm_encoder_slave *encoder_slave) struct drm_encoder_slave *encoder_slave)
{ {
struct tda998x_priv *priv; struct tda998x_priv *priv;
int ret;
priv = kzalloc(sizeof(*priv), GFP_KERNEL); priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv) if (!priv)
@ -1172,8 +1198,11 @@ tda998x_encoder_init(struct i2c_client *client,
tda998x_reset(priv); tda998x_reset(priv);
/* read version: */ /* read version: */
priv->rev = reg_read(priv, REG_VERSION_LSB) | ret = reg_read(priv, REG_VERSION_LSB) |
reg_read(priv, REG_VERSION_MSB) << 8; (reg_read(priv, REG_VERSION_MSB) << 8);
if (ret < 0)
goto fail;
priv->rev = ret;
/* mask off feature bits: */ /* mask off feature bits: */
priv->rev &= ~0x30; /* not-hdcp and not-scalar bit */ priv->rev &= ~0x30; /* not-hdcp and not-scalar bit */