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-rw-r--r--drivers/i2c/busses/i2c-designware-core.c11
-rw-r--r--drivers/i2c/busses/i2c-designware-core.h12
2 files changed, 23 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index f325ec7..dbecf08 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -317,6 +317,12 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
47, /* tLOW = 4.7 us */
3, /* tf = 0.3 us */
0); /* No offset */
+
+ /* Allow platforms to specify the ideal HCNT and LCNT values */
+ if (dev->ss_hcnt && dev->ss_lcnt) {
+ hcnt = dev->ss_hcnt;
+ lcnt = dev->ss_lcnt;
+ }
dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
@@ -331,6 +337,11 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
13, /* tLOW = 1.3 us */
3, /* tf = 0.3 us */
0); /* No offset */
+
+ if (dev->fs_hcnt && dev->fs_lcnt) {
+ hcnt = dev->fs_hcnt;
+ lcnt = dev->fs_lcnt;
+ }
dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 912aa22..e8a7565 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -61,6 +61,14 @@
* @tx_fifo_depth: depth of the hardware tx fifo
* @rx_fifo_depth: depth of the hardware rx fifo
* @rx_outstanding: current master-rx elements in tx fifo
+ * @ss_hcnt: standard speed HCNT value
+ * @ss_lcnt: standard speed LCNT value
+ * @fs_hcnt: fast speed HCNT value
+ * @fs_lcnt: fast speed LCNT value
+ *
+ * HCNT and LCNT parameters can be used if the platform knows more accurate
+ * values than the one computed based only on the input clock frequency.
+ * Leave them to be %0 if not used.
*/
struct dw_i2c_dev {
struct device *dev;
@@ -91,6 +99,10 @@ struct dw_i2c_dev {
unsigned int rx_fifo_depth;
int rx_outstanding;
u32 sda_hold_time;
+ u16 ss_hcnt;
+ u16 ss_lcnt;
+ u16 fs_hcnt;
+ u16 fs_lcnt;
};
#define ACCESS_SWAP 0x00000001