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[1/2] i2c: designware: Calculate SCL timing parameter for Fast Mode Plus

Message ID 20200407133439.23422-2-wan.ahmad.zainie.wan.mohamad@intel.com
State Accepted
Commit 85f8fcaeed33315e19905af23f2693a81956688a
Headers show
Series [1/2] i2c: designware: Calculate SCL timing parameter for Fast Mode Plus | expand

Commit Message

Wan Ahmad Zainie April 7, 2020, 1:34 p.m. UTC 
Custom parameters for HCNT/LCNT are not available for OF based system.
Thus, we will use existing SCL timing parameter calculation functions
for Fast Mode Plus.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/i2c/busses/i2c-designware-master.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 3a58eef20936..23038d7272da 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -76,14 +76,27 @@  static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
 	 */
 	if (t->bus_freq_hz == 1000000) {
 		/*
-		 * Check are fast mode plus parameters available and use
-		 * fast mode if not.
+		 * Check are Fast Mode Plus parameters available. Calculate
+		 * SCL timing parameters for Fast Mode Plus if not set.
 		 */
 		if (dev->fp_hcnt && dev->fp_lcnt) {
 			dev->fs_hcnt = dev->fp_hcnt;
 			dev->fs_lcnt = dev->fp_lcnt;
-			fp_str = " Plus";
+		} else {
+			ic_clk = i2c_dw_clk_rate(dev);
+			dev->fs_hcnt =
+				i2c_dw_scl_hcnt(ic_clk,
+						260,	/* tHIGH = 260 ns */
+						sda_falling_time,
+						0,	/* DW default */
+						0);	/* No offset */
+			dev->fs_lcnt =
+				i2c_dw_scl_lcnt(ic_clk,
+						500,	/* tLOW = 500 ns */
+						scl_falling_time,
+						0);	/* No offset */
 		}
+		fp_str = " Plus";
 	}
 	/*
 	 * Calculate SCL timing parameters for fast mode if not set. They are