mk-rootfs.sh

hc

2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376

 kernel/drivers/gpio/gpio-ts4900.c
..
..
@@ -1,7 +1,7 @@
1
1
 /*
2
2
  * Digital I/O driver for Technologic Systems I2C FPGA Core
3
3
  *
4
- * Copyright (C) 2015 Technologic Systems
4
+ * Copyright (C) 2015, 2018 Technologic Systems
5
5
  * Copyright (C) 2016 Savoir-Faire Linux
6
6
  *
7
7
  * This program is free software; you can redistribute it and/or
..
..
@@ -44,7 +44,10 @@
44
44
 
45
45
 	regmap_read(priv->regmap, offset, &reg);
46
46
 
47
-	return !(reg & TS4900_GPIO_OE);
47
+	if (reg & TS4900_GPIO_OE)
48
+		return GPIO_LINE_DIRECTION_OUT;
49
+
50
+	return GPIO_LINE_DIRECTION_IN;
48
51
 }
49
52
 
50
53
 static int ts4900_gpio_direction_input(struct gpio_chip *chip,
..
..
@@ -52,19 +55,33 @@
52
55
 {
53
56
 	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
54
57
 
55
-	/*
56
-	 * This will clear the output enable bit, the other bits are
57
-	 * dontcare when this is cleared
58
+	/* Only clear the OE bit here, requires a RMW. Prevents potential issue
59
+	 * with OE and data getting to the physical pin at different times.
58
60
 	 */
59
-	return regmap_write(priv->regmap, offset, 0);
61
+	return regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OE, 0);
60
62
 }
61
63
 
62
64
 static int ts4900_gpio_direction_output(struct gpio_chip *chip,
63
65
 					unsigned int offset, int value)
64
66
 {
65
67
 	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
68
+	unsigned int reg;
66
69
 	int ret;
67
70
 
71
+	/* If changing from an input to an output, we need to first set the
72
+	 * proper data bit to what is requested and then set OE bit. This
73
+	 * prevents a glitch that can occur on the IO line
74
+	 */
75
+	regmap_read(priv->regmap, offset, &reg);
76
+	if (!(reg & TS4900_GPIO_OE)) {
77
+		if (value)
78
+			reg = TS4900_GPIO_OUT;
79
+		else
80
+			reg &= ~TS4900_GPIO_OUT;
81
+
82
+		regmap_write(priv->regmap, offset, reg);
83
+	}
84
+
68
85
 	if (value)
69
86
 		ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE |
70
87
 							 TS4900_GPIO_OUT);