| Message ID | 1443602831-27069-1-git-send-email-ludovic.desroches@atmel.com |
|---|---|
| State | Superseded |
| Headers | show |
Hi all, it looks good to me. Le 30/09/2015 10:47, Ludovic Desroches a écrit : > From: Wenyou Yang <wenyou.yang@atmel.com> > > Add the HOLD field setting in order to support I2C slave devices which need > a longer hold time of the data. > Since it depends on the slave devices connected to the bus, add a DT > property "atmel,twd-hold-cycles" to specify this HOLD field. > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> > Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Acked-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> > --- > drivers/i2c/busses/i2c-at91.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c > index 1c758cd..06e66ef 100644 > --- a/drivers/i2c/busses/i2c-at91.c > +++ b/drivers/i2c/busses/i2c-at91.c > @@ -64,6 +64,7 @@ > #define AT91_TWI_IADR 0x000c /* Internal Address Register */ > > #define AT91_TWI_CWGR 0x0010 /* Clock Waveform Generator Reg */ > +#define AT91_TWI_CWGR_HOLD(x) (((x) & 0x1f) << 24) > > #define AT91_TWI_SR 0x0020 /* Status Register */ > #define AT91_TWI_TXCOMP BIT(0) /* Transmission Complete */ > @@ -185,7 +186,8 @@ static void at91_init_twi_bus(struct at91_twi_dev *dev) > * Calculate symmetric clock as stated in datasheet: > * twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset)) > */ > -static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) > +static void at91_calc_twi_clock(struct at91_twi_dev *dev, > + int twi_clk, u32 twd_hold) > { > int ckdiv, cdiv, div; > struct at91_twi_pdata *pdata = dev->pdata; > @@ -204,7 +206,9 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) > cdiv = 255; > } > > - dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv; > + dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv > + | AT91_TWI_CWGR_HOLD(twd_hold); > + > dev_dbg(dev->dev, "cdiv %d ckdiv %d\n", cdiv, ckdiv); > } > > @@ -936,6 +940,7 @@ static int at91_twi_probe(struct platform_device *pdev) > int rc; > u32 phy_addr; > u32 bus_clk_rate; > + u32 twd_hold_cycles; > > dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); > if (!dev) > @@ -992,7 +997,12 @@ static int at91_twi_probe(struct platform_device *pdev) > if (rc) > bus_clk_rate = DEFAULT_TWI_CLK_HZ; > > - at91_calc_twi_clock(dev, bus_clk_rate); > + rc = of_property_read_u32(dev->dev->of_node, > + "atmel,twd-hold-cycles", &twd_hold_cycles); > + if (rc) > + twd_hold_cycles = 0; > + > + at91_calc_twi_clock(dev, bus_clk_rate, twd_hold_cycles); > at91_init_twi_bus(dev); > > snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index 1c758cd..06e66ef 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -64,6 +64,7 @@ #define AT91_TWI_IADR 0x000c /* Internal Address Register */ #define AT91_TWI_CWGR 0x0010 /* Clock Waveform Generator Reg */ +#define AT91_TWI_CWGR_HOLD(x) (((x) & 0x1f) << 24) #define AT91_TWI_SR 0x0020 /* Status Register */ #define AT91_TWI_TXCOMP BIT(0) /* Transmission Complete */ @@ -185,7 +186,8 @@ static void at91_init_twi_bus(struct at91_twi_dev *dev) * Calculate symmetric clock as stated in datasheet: * twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset)) */ -static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) +static void at91_calc_twi_clock(struct at91_twi_dev *dev, + int twi_clk, u32 twd_hold) { int ckdiv, cdiv, div; struct at91_twi_pdata *pdata = dev->pdata; @@ -204,7 +206,9 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) cdiv = 255; } - dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv; + dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv + | AT91_TWI_CWGR_HOLD(twd_hold); + dev_dbg(dev->dev, "cdiv %d ckdiv %d\n", cdiv, ckdiv); } @@ -936,6 +940,7 @@ static int at91_twi_probe(struct platform_device *pdev) int rc; u32 phy_addr; u32 bus_clk_rate; + u32 twd_hold_cycles; dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); if (!dev) @@ -992,7 +997,12 @@ static int at91_twi_probe(struct platform_device *pdev) if (rc) bus_clk_rate = DEFAULT_TWI_CLK_HZ; - at91_calc_twi_clock(dev, bus_clk_rate); + rc = of_property_read_u32(dev->dev->of_node, + "atmel,twd-hold-cycles", &twd_hold_cycles); + if (rc) + twd_hold_cycles = 0; + + at91_calc_twi_clock(dev, bus_clk_rate, twd_hold_cycles); at91_init_twi_bus(dev); snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");