From 49b4c54bc969aae9a79e598266feec3d74275635 Mon Sep 17 00:00:00 2001
From: Tomas Novotny <tomas@novotny.cz>
Date: Wed, 25 Nov 2020 18:42:16 +0100
Subject: [PATCH] gpio: tca642x: fix input subcommand for gpio banks > 0

The value of input pin for bank > 0 is always 0 for input subcommand.
The reason is that gpio_bank variable is computed only for invert and
output subcommands (it depends on number of arguments). The default
value of zero causes to shift the mask away for banks > 0.

Please note that info subcommand works as expected, because the input
pin values are accessed differently.

Fixes: 61c1775f16ed ("gpio: tca642x: Add the tca642x gpio expander driver")
Cc: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Tomas Novotny <tomas@novotny.cz>
---
 drivers/gpio/tca642x.c | 49 ++++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 14 deletions(-)

diff --git a/drivers/gpio/tca642x.c b/drivers/gpio/tca642x.c
index 463cfe879a..7007c7a002 100644
--- a/drivers/gpio/tca642x.c
+++ b/drivers/gpio/tca642x.c
@@ -213,6 +213,24 @@ static int tca642x_info(uchar chip)
 	return 0;
 }
 
+static int tca642x_get_bank(int pin)
+{
+	int gpio_bank;
+
+	if (pin <= 7) {
+		gpio_bank = 0;
+	} else if ((pin >= 10) && (pin <= 17)) {
+		gpio_bank = 1;
+	} else if ((pin >= 20) && (pin <= 27)) {
+		gpio_bank = 2;
+	} else {
+		printf("Requested pin is not available\n");
+		gpio_bank = -1;
+	}
+
+	return gpio_bank;
+}
+
 static struct cmd_tbl cmd_tca642x[] = {
 	U_BOOT_CMD_MKENT(device, 3, 0, (void *)TCA642X_CMD_DEVICE, "", ""),
 	U_BOOT_CMD_MKENT(output, 4, 0, (void *)TCA642X_CMD_OUTPUT, "", ""),
@@ -226,7 +244,7 @@ static int do_tca642x(struct cmd_tbl *cmdtp, int flag, int argc,
 {
 	static uchar chip = CONFIG_SYS_I2C_TCA642X_ADDR;
 	int ret = CMD_RET_USAGE, val;
-	uint8_t gpio_bank = 0;
+	int gpio_bank = 0;
 	uint8_t bank_shift;
 	ulong ul_arg2 = 0;
 	ulong ul_arg3 = 0;
@@ -247,20 +265,8 @@ static int do_tca642x(struct cmd_tbl *cmdtp, int flag, int argc,
 		ul_arg2 = simple_strtoul(argv[2], NULL, 10);
 
 	/* arg3 used as pin or invert value */
-	if (argc > 3) {
+	if (argc > 3)
 		ul_arg3 = simple_strtoul(argv[3], NULL, 10) & 0x1;
-		if (ul_arg2 <= 7) {
-			gpio_bank = 0;
-		} else if ((ul_arg2 >= 10) && (ul_arg2 <= 17)) {
-			gpio_bank = 1;
-		} else if ((ul_arg2 >= 20) && (ul_arg2 <= 27)) {
-			gpio_bank = 2;
-		} else {
-			printf("Requested pin is not available\n");
-			ret = CMD_RET_FAILURE;
-			goto error;
-		}
-	}
 
 	switch ((int)c->cmd) {
 	case TCA642X_CMD_INFO:
@@ -277,6 +283,11 @@ static int do_tca642x(struct cmd_tbl *cmdtp, int flag, int argc,
 		break;
 
 	case TCA642X_CMD_INPUT:
+		gpio_bank = tca642x_get_bank(ul_arg2);
+		if (gpio_bank < 0) {
+			ret = CMD_RET_FAILURE;
+			goto error;
+		}
 		bank_shift = ul_arg2 - (gpio_bank * 10);
 		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
 				TCA642X_DIR_IN << bank_shift);
@@ -291,6 +302,11 @@ static int do_tca642x(struct cmd_tbl *cmdtp, int flag, int argc,
 		break;
 
 	case TCA642X_CMD_OUTPUT:
+		gpio_bank = tca642x_get_bank(ul_arg2);
+		if (gpio_bank < 0) {
+			ret = CMD_RET_FAILURE;
+			goto error;
+		}
 		bank_shift = ul_arg2 - (gpio_bank * 10);
 		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
 				(TCA642X_DIR_OUT << bank_shift));
@@ -303,6 +319,11 @@ static int do_tca642x(struct cmd_tbl *cmdtp, int flag, int argc,
 		break;
 
 	case TCA642X_CMD_INVERT:
+		gpio_bank = tca642x_get_bank(ul_arg2);
+		if (gpio_bank < 0) {
+			ret = CMD_RET_FAILURE;
+			goto error;
+		}
 		bank_shift = ul_arg2 - (gpio_bank * 10);
 		ret = tca642x_set_pol(chip, gpio_bank, (1 << bank_shift),
 					(ul_arg3 << bank_shift));