| Message ID | 1371808422-27742-1-git-send-email-christian.ruppert@abilis.com |
|---|---|
| State | Changes Requested |
| Headers | show |
Hi, On Fri, Jun 21, 2013 at 11:53:42AM +0200, Christian Ruppert wrote: > This patch makes the SDA hold time configurable through device tree. > > Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com> > Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com> > --- > .../devicetree/bindings/i2c/i2c-designware.txt | 14 ++++++++++++++ > arch/arc/boot/dts/abilis_tb100_dvk.dts | 10 +++++----- > arch/arc/boot/dts/abilis_tb101_dvk.dts | 10 +++++----- Vineet, an ack for those would be nice since I think it is better if I take all this via I2C. > drivers/i2c/busses/i2c-designware-core.c | 13 +++++++++++++ > drivers/i2c/busses/i2c-designware-core.h | 1 + > drivers/i2c/busses/i2c-designware-platdrv.c | 10 ++++++++++ > 6 files changed, 48 insertions(+), 10 deletions(-) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt > index e42a2ee..3266cc7 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt > @@ -10,6 +10,9 @@ Recommended properties : > > - clock-frequency : desired I2C bus clock frequency in Hz. > > +Optional properties : > + - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds. Not on all versions, should be mentioned here. > + > Example : > > i2c@f0000 { > @@ -20,3 +23,14 @@ Example : > interrupts = <11>; > clock-frequency = <400000>; > }; > + > + i2c@1120000 { > + #address-cells = <1>; > + #size-cells = <0>; > + compatible = "snps,designware-i2c"; > + reg = <0x1120000 0x1000>; > + interrupt-parent = <&ictl>; > + interrupts = <12 1>; > + clock-frequency = <400000>; > + i2c-sda-hold-time-ns = <300>; > + }; > diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c > index c41ca63..66119e2 100644 > --- a/drivers/i2c/busses/i2c-designware-core.c > +++ b/drivers/i2c/busses/i2c-designware-core.c > @@ -67,9 +67,12 @@ > #define DW_IC_STATUS 0x70 > #define DW_IC_TXFLR 0x74 > #define DW_IC_RXFLR 0x78 > +#define DW_IC_SDA_HOLD 0x7c > #define DW_IC_TX_ABRT_SOURCE 0x80 > #define DW_IC_ENABLE_STATUS 0x9c > #define DW_IC_COMP_PARAM_1 0xf4 > +#define DW_IC_COMP_VERSION 0xf8 > +#define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A > #define DW_IC_COMP_TYPE 0xfc > #define DW_IC_COMP_TYPE_VALUE 0x44570140 > > @@ -332,6 +335,16 @@ int i2c_dw_init(struct dw_i2c_dev *dev) > dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); > dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); > > + /* Configure SDA Hold Time if required */ > + reg = dw_readl(dev, DW_IC_COMP_VERSION); Why not reading reg inside the if-block? Thanks, Wolfram
On 06/25/2013 10:09 PM, Wolfram Sang wrote: > Hi, > > On Fri, Jun 21, 2013 at 11:53:42AM +0200, Christian Ruppert wrote: >> > This patch makes the SDA hold time configurable through device tree. >> > >> > Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com> >> > Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com> >> > --- >> > .../devicetree/bindings/i2c/i2c-designware.txt | 14 ++++++++++++++ >> > arch/arc/boot/dts/abilis_tb100_dvk.dts | 10 +++++----- >> > arch/arc/boot/dts/abilis_tb101_dvk.dts | 10 +++++----- > Vineet, an ack for those would be nice since I think it is better if I > take all this via I2C. > Certainly, I was waiting for you guys to converge :-) Acked-by: Vineet Gupta <vgupta@synopsys.com> # for arch/arc/boot/dts/* -Vineet -- 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/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt index e42a2ee..3266cc7 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt @@ -10,6 +10,9 @@ Recommended properties : - clock-frequency : desired I2C bus clock frequency in Hz. +Optional properties : + - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds. + Example : i2c@f0000 { @@ -20,3 +23,14 @@ Example : interrupts = <11>; clock-frequency = <400000>; }; + + i2c@1120000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "snps,designware-i2c"; + reg = <0x1120000 0x1000>; + interrupt-parent = <&ictl>; + interrupts = <12 1>; + clock-frequency = <400000>; + i2c-sda-hold-time-ns = <300>; + }; diff --git a/arch/arc/boot/dts/abilis_tb100_dvk.dts b/arch/arc/boot/dts/abilis_tb100_dvk.dts index 0fa0d4a..ebc313a 100644 --- a/arch/arc/boot/dts/abilis_tb100_dvk.dts +++ b/arch/arc/boot/dts/abilis_tb100_dvk.dts @@ -45,19 +45,19 @@ }; i2c0: i2c@FF120000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c1: i2c@FF121000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c2: i2c@FF122000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c3: i2c@FF123000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c4: i2c@FF124000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; leds { diff --git a/arch/arc/boot/dts/abilis_tb101_dvk.dts b/arch/arc/boot/dts/abilis_tb101_dvk.dts index a4d80ce..b204657 100644 --- a/arch/arc/boot/dts/abilis_tb101_dvk.dts +++ b/arch/arc/boot/dts/abilis_tb101_dvk.dts @@ -45,19 +45,19 @@ }; i2c0: i2c@FF120000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c1: i2c@FF121000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c2: i2c@FF122000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c3: i2c@FF123000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c4: i2c@FF124000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; leds { diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index c41ca63..66119e2 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -67,9 +67,12 @@ #define DW_IC_STATUS 0x70 #define DW_IC_TXFLR 0x74 #define DW_IC_RXFLR 0x78 +#define DW_IC_SDA_HOLD 0x7c #define DW_IC_TX_ABRT_SOURCE 0x80 #define DW_IC_ENABLE_STATUS 0x9c #define DW_IC_COMP_PARAM_1 0xf4 +#define DW_IC_COMP_VERSION 0xf8 +#define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A #define DW_IC_COMP_TYPE 0xfc #define DW_IC_COMP_TYPE_VALUE 0x44570140 @@ -332,6 +335,16 @@ int i2c_dw_init(struct dw_i2c_dev *dev) dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); + /* Configure SDA Hold Time if required */ + reg = dw_readl(dev, DW_IC_COMP_VERSION); + if (dev->sda_hold_time) { + if (reg >= DW_IC_SDA_HOLD_MIN_VERS) + dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); + else + dev_warn(dev->dev, + "Hardware too old to adjust SDA hold time."); + } + /* Configure Tx/Rx FIFO threshold levels */ dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL); dw_writel(dev, 0, DW_IC_RX_TL); diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index e761ad1..912aa22 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -90,6 +90,7 @@ struct dw_i2c_dev { unsigned int tx_fifo_depth; unsigned int rx_fifo_depth; int rx_outstanding; + u32 sda_hold_time; }; #define ACCESS_SWAP 0x00000001 diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 35b70a1..8b9d3f1 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -34,6 +34,7 @@ #include <linux/sched.h> #include <linux/err.h> #include <linux/interrupt.h> +#include <linux/of.h> #include <linux/of_i2c.h> #include <linux/platform_device.h> #include <linux/pm.h> @@ -121,6 +122,15 @@ static int dw_i2c_probe(struct platform_device *pdev) return PTR_ERR(dev->clk); clk_prepare_enable(dev->clk); + if (pdev->dev.of_node) { + u32 ht = 0; + u32 ic_clk = dev->get_clk_rate_khz(dev); + + of_property_read_u32(pdev->dev.of_node, + "i2c-sda-hold-time-ns", &ht); + dev->sda_hold_time = ((u64)ic_clk * ht + 500000) / 1000000; + } + dev->functionality = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |