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| author | Ismael Luceno Cortes <ismael.luceno@silicon-gears.com> | 2019-03-07 18:00:51 +0000 |
|---|---|---|
| committer | Heiko Schocher <hs@denx.de> | 2019-03-08 05:53:11 +0100 |
| commit | 3b59eaef4fa6139b86203db55b2e90aad1befa61 (patch) | |
| tree | 93ddb187ef212686782241df5af2bd7991ff68d5 /drivers/i2c | |
| parent | 4fcff08c4b4fe4e8e0e000fd2c2d97b8dec68d35 (diff) | |
| download | u-boot-3b59eaef4fa6139b86203db55b2e90aad1befa61.zip u-boot-3b59eaef4fa6139b86203db55b2e90aad1befa61.tar.gz u-boot-3b59eaef4fa6139b86203db55b2e90aad1befa61.tar.bz2 | |
i2c: rcar_i2c: Add comments about registers & values
Document the meaning of macros related to registers and values to be
written to them.
Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/rcar_i2c.c | 47 |
1 files changed, 26 insertions, 21 deletions
diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c index a57f72a..d7b2720 100644 --- a/drivers/i2c/rcar_i2c.c +++ b/drivers/i2c/rcar_i2c.c @@ -18,35 +18,40 @@ #include <asm/io.h> #include <wait_bit.h> -#define RCAR_I2C_ICSCR 0x00 -#define RCAR_I2C_ICMCR 0x04 -#define RCAR_I2C_ICMCR_MDBS BIT(7) -#define RCAR_I2C_ICMCR_FSCL BIT(6) -#define RCAR_I2C_ICMCR_FSDA BIT(5) -#define RCAR_I2C_ICMCR_OBPC BIT(4) -#define RCAR_I2C_ICMCR_MIE BIT(3) +#define RCAR_I2C_ICSCR 0x00 /* slave ctrl */ +#define RCAR_I2C_ICMCR 0x04 /* master ctrl */ +#define RCAR_I2C_ICMCR_MDBS BIT(7) /* non-fifo mode switch */ +#define RCAR_I2C_ICMCR_FSCL BIT(6) /* override SCL pin */ +#define RCAR_I2C_ICMCR_FSDA BIT(5) /* override SDA pin */ +#define RCAR_I2C_ICMCR_OBPC BIT(4) /* override pins */ +#define RCAR_I2C_ICMCR_MIE BIT(3) /* master if enable */ #define RCAR_I2C_ICMCR_TSBE BIT(2) -#define RCAR_I2C_ICMCR_FSB BIT(1) -#define RCAR_I2C_ICMCR_ESG BIT(0) -#define RCAR_I2C_ICSSR 0x08 -#define RCAR_I2C_ICMSR 0x0c +#define RCAR_I2C_ICMCR_FSB BIT(1) /* force stop bit */ +#define RCAR_I2C_ICMCR_ESG BIT(0) /* enable start bit gen */ +#define RCAR_I2C_ICSSR 0x08 /* slave status */ +#define RCAR_I2C_ICMSR 0x0c /* master status */ #define RCAR_I2C_ICMSR_MASK 0x7f -#define RCAR_I2C_ICMSR_MNR BIT(6) -#define RCAR_I2C_ICMSR_MAL BIT(5) -#define RCAR_I2C_ICMSR_MST BIT(4) +#define RCAR_I2C_ICMSR_MNR BIT(6) /* Nack */ +#define RCAR_I2C_ICMSR_MAL BIT(5) /* Arbitration lost */ +#define RCAR_I2C_ICMSR_MST BIT(4) /* Stop */ #define RCAR_I2C_ICMSR_MDE BIT(3) #define RCAR_I2C_ICMSR_MDT BIT(2) #define RCAR_I2C_ICMSR_MDR BIT(1) #define RCAR_I2C_ICMSR_MAT BIT(0) -#define RCAR_I2C_ICSIER 0x10 -#define RCAR_I2C_ICMIER 0x14 -#define RCAR_I2C_ICCCR 0x18 +#define RCAR_I2C_ICSIER 0x10 /* slave irq enable */ +#define RCAR_I2C_ICMIER 0x14 /* master irq enable */ +#define RCAR_I2C_ICCCR 0x18 /* clock dividers */ #define RCAR_I2C_ICCCR_SCGD_OFF 3 -#define RCAR_I2C_ICSAR 0x1c -#define RCAR_I2C_ICMAR 0x20 -#define RCAR_I2C_ICRXD_ICTXD 0x24 +#define RCAR_I2C_ICSAR 0x1c /* slave address */ +#define RCAR_I2C_ICMAR 0x20 /* master address */ +#define RCAR_I2C_ICRXD_ICTXD 0x24 /* data port */ +/* + * First Bit Setup Cycle (Gen3). + * Defines 1st bit delay between SDA and SCL. + */ #define RCAR_I2C_ICFBSCR 0x38 -#define RCAR_I2C_ICFBSCR_TCYC17 0x0f +#define RCAR_I2C_ICFBSCR_TCYC17 0x0f /* 17*Tcyc */ + enum rcar_i2c_type { RCAR_I2C_TYPE_GEN2, |