[PATCH 4/6] input: himax_hx83112b: implement MCU register reading

From: Felix Kaechele
Date: Fri May 03 2024 - 22:15:39 EST


Implement reading from the MCU in a more universal fashion. This allows
properly handling reads of more than 4 bytes using the AHB FIFO
implemented in the chip.

Signed-off-by: Felix Kaechele <felix@xxxxxxxxxxx>
---
drivers/input/touchscreen/himax_hx83112b.c | 51 ++++++++++++++++++++--
1 file changed, 48 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/himax_hx83112b.c b/drivers/input/touchscreen/himax_hx83112b.c
index ba5442cc0a24..0173ff394a99 100644
--- a/drivers/input/touchscreen/himax_hx83112b.c
+++ b/drivers/input/touchscreen/himax_hx83112b.c
@@ -29,9 +29,13 @@
#define HIMAX_AHB_ADDR_BYTE_0 0x00
#define HIMAX_AHB_ADDR_RDATA_BYTE_0 0x08
#define HIMAX_AHB_ADDR_ACCESS_DIRECTION 0x0c
+#define HIMAX_AHB_ADDR_INCR4 0x0d
+#define HIMAX_AHB_ADDR_CONTI 0x13
#define HIMAX_AHB_ADDR_EVENT_STACK 0x30

#define HIMAX_AHB_CMD_ACCESS_DIRECTION_READ 0x00
+#define HIMAX_AHB_CMD_INCR4 0x10
+#define HIMAX_AHB_CMD_CONTI 0x31

#define HIMAX_REG_ADDR_ICID 0x900000d0

@@ -73,10 +77,34 @@ static const char *const himax_supply_names[] = {
"vdd",
};

-static int himax_read_config(struct himax_ts_data *ts, u32 address, u32 *dst)
+static int himax_bus_enable_burst(struct himax_ts_data *ts)
{
int error;

+ error = regmap_write(ts->regmap, HIMAX_AHB_ADDR_CONTI,
+ HIMAX_AHB_CMD_CONTI);
+ if (error)
+ return error;
+
+ error = regmap_write(ts->regmap, HIMAX_AHB_ADDR_INCR4,
+ HIMAX_AHB_CMD_INCR4);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static int himax_bus_read(struct himax_ts_data *ts, u32 address, void *dst,
+ size_t length)
+{
+ int error;
+
+ if (length > 4) {
+ error = himax_bus_enable_burst(ts);
+ if (error)
+ return error;
+ }
+
error = regmap_write(ts->regmap, HIMAX_AHB_ADDR_BYTE_0, address);
if (error)
return error;
@@ -86,7 +114,24 @@ static int himax_read_config(struct himax_ts_data *ts, u32 address, u32 *dst)
if (error)
return error;

- error = regmap_read(ts->regmap, HIMAX_AHB_ADDR_RDATA_BYTE_0, dst);
+ if (length > 4)
+ error = regmap_noinc_read(ts->regmap,
+ HIMAX_AHB_ADDR_RDATA_BYTE_0,
+ dst, length);
+ else
+ error = regmap_read(ts->regmap,
+ HIMAX_AHB_ADDR_RDATA_BYTE_0, dst);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static int himax_read_mcu(struct himax_ts_data *ts, u32 address, u32 *dst)
+{
+ int error;
+
+ error = himax_bus_read(ts, address, dst, sizeof(dst));
if (error)
return error;

@@ -112,7 +157,7 @@ static int himax_read_product_id(struct himax_ts_data *ts, u32 *product_id)
{
int error;

- error = himax_read_config(ts, HIMAX_REG_ADDR_ICID, product_id);
+ error = himax_read_mcu(ts, HIMAX_REG_ADDR_ICID, product_id);
if (error)
return error;

--
2.44.0