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Message-Id: <20221129151959.26052-3-l.ellero@asem.it>
Date: Tue, 29 Nov 2022 16:19:58 +0100
From: Luca Ellero <l.ellero@...m.it>
To: dmitry.torokhov@...il.com, daniel@...que.org,
m.felsch@...gutronix.de, andriy.shevchenko@...ux.intel.com,
u.kleine-koenig@...gutronix.de, mkl@...gutronix.de,
miquel.raynal@...tlin.com, imre.deak@...ia.com,
luca.ellero@...ckedbrain.com
Cc: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
Luca Ellero <l.ellero@...m.it>
Subject: [PATCH 2/3] ads7846: always set last command to PWRDOWN
Controllers that report pressure (e.g. ADS7846) use 5 commands and the
correct sequence is READ_X, READ_Y, READ_Z1, READ_Z2, PWRDOWN.
Controllers that don't report pressure (e.g. ADS7845/ADS7843) use only 3
commands and the correct sequence should be READ_X, READ_Y, PWRDOWN. But
the sequence sent was incorrect: READ_X, READ_Y, READ_Z1.
This patch fixes it.
Signed-off-by: Luca Ellero <l.ellero@...m.it>
---
drivers/input/touchscreen/ads7846.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 24605c40d039..9e15cdf6faa0 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -1066,6 +1066,9 @@ static int ads7846_setup_spi_msg(struct ads7846 *ts,
struct ads7846_buf_layout *l = &packet->l[cmd_idx];
unsigned int max_count;
+ if (cmd_idx == packet->cmds - 1)
+ cmd_idx = ADS7846_PWDOWN;
+
if (ads7846_cmd_need_settle(cmd_idx))
max_count = packet->count + packet->count_skip;
else
@@ -1102,7 +1105,12 @@ static int ads7846_setup_spi_msg(struct ads7846 *ts,
for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) {
struct ads7846_buf_layout *l = &packet->l[cmd_idx];
- u8 cmd = ads7846_get_cmd(cmd_idx, vref);
+ u8 cmd;
+
+ if (cmd_idx == packet->cmds - 1)
+ cmd_idx = ADS7846_PWDOWN;
+
+ cmd = ads7846_get_cmd(cmd_idx, vref);
for (b = 0; b < l->count; b++)
packet->tx[l->offset + b].cmd = cmd;
--
2.25.1
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