From d2ccde1c8e90d38cee87a1b0309ad2827f3fd30d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 02:45:28 +0000
Subject: [PATCH] add boot partition  size

---
 kernel/drivers/gpio/gpio-ts4900.c |   29 +++++++++++++++++++++++------
 1 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/kernel/drivers/gpio/gpio-ts4900.c b/kernel/drivers/gpio/gpio-ts4900.c
index 1da8d05..d918d2d 100644
--- a/kernel/drivers/gpio/gpio-ts4900.c
+++ b/kernel/drivers/gpio/gpio-ts4900.c
@@ -1,7 +1,7 @@
 /*
  * Digital I/O driver for Technologic Systems I2C FPGA Core
  *
- * Copyright (C) 2015 Technologic Systems
+ * Copyright (C) 2015, 2018 Technologic Systems
  * Copyright (C) 2016 Savoir-Faire Linux
  *
  * This program is free software; you can redistribute it and/or
@@ -44,7 +44,10 @@
 
 	regmap_read(priv->regmap, offset, &reg);
 
-	return !(reg & TS4900_GPIO_OE);
+	if (reg & TS4900_GPIO_OE)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
 }
 
 static int ts4900_gpio_direction_input(struct gpio_chip *chip,
@@ -52,19 +55,33 @@
 {
 	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
 
-	/*
-	 * This will clear the output enable bit, the other bits are
-	 * dontcare when this is cleared
+	/* Only clear the OE bit here, requires a RMW. Prevents potential issue
+	 * with OE and data getting to the physical pin at different times.
 	 */
-	return regmap_write(priv->regmap, offset, 0);
+	return regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OE, 0);
 }
 
 static int ts4900_gpio_direction_output(struct gpio_chip *chip,
 					unsigned int offset, int value)
 {
 	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
+	unsigned int reg;
 	int ret;
 
+	/* If changing from an input to an output, we need to first set the
+	 * proper data bit to what is requested and then set OE bit. This
+	 * prevents a glitch that can occur on the IO line
+	 */
+	regmap_read(priv->regmap, offset, &reg);
+	if (!(reg & TS4900_GPIO_OE)) {
+		if (value)
+			reg = TS4900_GPIO_OUT;
+		else
+			reg &= ~TS4900_GPIO_OUT;
+
+		regmap_write(priv->regmap, offset, reg);
+	}
+
 	if (value)
 		ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE |
 							 TS4900_GPIO_OUT);

--
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