[PATCH v3 1/1] i2c: qcom-geni: Support systems with 32MHz serial engine clock

[Manikanta Mylavarapu <quic_mmanikan@xxxxxxxxxxx>]

In existing socs, I2C serial engine is sourced from XO (19.2MHz).
Where as in IPQ5424, I2C serial engine is sourced from GPLL0 (32MHz).

The existing map table is based on 19.2MHz. This patch incorporates
the clock map table to derive the SCL clock from the 32MHz source
clock frequency.

Signed-off-by: Manikanta Mylavarapu <quic_mmanikan@xxxxxxxxxxx>
---
Changes in v3:
	- Updated geni_i2c_clk_map_32mhz array values
	- Added sentinel value to both 19.2MHz, 32MHz clk map arrays
	- Updated loop termination condition based on sentinel value

 drivers/i2c/busses/i2c-qcom-geni.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 212336f724a6..579c01686823 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -16,6 +16,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/soc/qcom/geni-se.h>
 #include <linux/spinlock.h>
+#include <linux/units.h>
 
 #define SE_I2C_TX_TRANS_LEN		0x26c
 #define SE_I2C_RX_TRANS_LEN		0x270
@@ -146,22 +147,36 @@ struct geni_i2c_clk_fld {
  * clk_freq_out = t / t_cycle
  * source_clock = 19.2 MHz
  */
-static const struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
+static const struct geni_i2c_clk_fld geni_i2c_clk_map_19p2mhz[] = {
 	{KHZ(100), 7, 10, 11, 26},
 	{KHZ(400), 2,  5, 12, 24},
 	{KHZ(1000), 1, 3,  9, 18},
+	{},
+};
+
+/* source_clock = 32 MHz */
+static const struct geni_i2c_clk_fld geni_i2c_clk_map_32mhz[] = {
+	{KHZ(100), 8, 14, 18, 40},
+	{KHZ(400), 4,  3, 11, 20},
+	{KHZ(1000), 2, 3,  6, 15},
+	{},
 };
 
 static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
 {
-	int i;
-	const struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;
+	const struct geni_i2c_clk_fld *itr;
+
+	if (clk_get_rate(gi2c->se.clk) == 32 * HZ_PER_MHZ)
+		itr = geni_i2c_clk_map_32mhz;
+	else
+		itr = geni_i2c_clk_map_19p2mhz;
 
-	for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
+	while (itr->clk_freq_out != 0) {
 		if (itr->clk_freq_out == gi2c->clk_freq_out) {
 			gi2c->clk_fld = itr;
 			return 0;
 		}
+		itr++;
 	}
 	return -EINVAL;
 }
-- 
2.34.1