renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2025-01-17 18:14:34 +08:00
Code

i2c: Blackfin TWI: make sure we don't end up with a CLKDIV=0

Browse Source 
Make sure we don't end up with an invalid CLKDIV=0 in case someone
specifies 20kHz SCL or less (5 * 1024 / 20 = 0x100).

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
[ben-linux@fluff.org: shortened subject line]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
Michael Hennerich 2009-05-18 08:14:41 -04:00 committed by Ben Dooks
parent f3ad116588
commit 9528d1c7a5
2 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/i2c/busses/Kconfig
View File

@ -298,7 +298,7 @@ config I2C_BLACKFIN_TWI
config I2C_BLACKFIN_TWI_CLK_KHZ config I2C_BLACKFIN_TWI_CLK_KHZ
int "Blackfin TWI I2C clock (kHz)" int "Blackfin TWI I2C clock (kHz)"
depends on I2C_BLACKFIN_TWI depends on I2C_BLACKFIN_TWI
range 10 400 range 21 400
default 50 default 50
help help
The unit of the TWI clock is kHz. The unit of the TWI clock is kHz.

11
drivers/i2c/busses/i2c-bfin-twi.c
View File

@ -614,6 +614,7 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
struct i2c_adapter *p_adap; struct i2c_adapter *p_adap;
struct resource *res; struct resource *res;
int rc; int rc;
unsigned int clkhilow;
iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL); iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
if (!iface) { if (!iface) {
@ -675,10 +676,14 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
/* Set TWI internal clock as 10MHz */ /* Set TWI internal clock as 10MHz */
write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F); write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
/*
* We will not end up with a CLKDIV=0 because no one will specify
* 20kHz SCL or less in Kconfig now. (5 * 1024 / 20 = 0x100)
*/
clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ;
/* Set Twi interface clock as specified */ /* Set Twi interface clock as specified */
write_CLKDIV(iface, ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
<< 8) | ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
& 0xFF));
/* Enable TWI */ /* Enable TWI */
write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA); write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);