From fa2c7a694fbe76dfedf58935d9582afcfba2caa1 Mon Sep 17 00:00:00 2001
From: Alan Carvalho de Assis <acassis@gmail.com>
Date: Fri, 9 Jun 2017 15:09:03 -0600
Subject: [PATCH] stm32f103-minimum: Fix a small BUG when reading from output
 pin.  We need a different read_ops to read from output pin. This patch fixes
 the issue:

nsh> gpio -o 0 /dev/gpout1
Driver: /dev/gpout1
  Output pin:    Value=1
  Writing:       Value=0
  Verify:        Value=1

Now:

nsh> gpio -o 0 /dev/gpout1
Driver: /dev/gpout1
  Output pin:    Value=1
  Writing:       Value=0
  Verify:        Value=0
---
 configs/stm32f103-minimum/src/stm32_gpio.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/configs/stm32f103-minimum/src/stm32_gpio.c b/configs/stm32f103-minimum/src/stm32_gpio.c
index 6335acc4a3..854b84a793 100644
--- a/configs/stm32f103-minimum/src/stm32_gpio.c
+++ b/configs/stm32f103-minimum/src/stm32_gpio.c
@@ -67,7 +67,6 @@ struct stm32gpio_dev_s
 {
   struct gpio_dev_s gpio;
   uint8_t id;
-  bool value;
 };
 
 struct stm32gpint_dev_s
@@ -81,6 +80,7 @@ struct stm32gpint_dev_s
  ****************************************************************************/
 
 static int gpin_read(FAR struct gpio_dev_s *dev, FAR bool *value);
+static int gpout_read(FAR struct gpio_dev_s *dev, FAR bool *value);
 static int gpout_write(FAR struct gpio_dev_s *dev, bool value);
 static int gpint_attach(FAR struct gpio_dev_s *dev,
                         pin_interrupt_t callback);
@@ -100,7 +100,7 @@ static const struct gpio_operations_s gpin_ops =
 
 static const struct gpio_operations_s gpout_ops =
 {
-  .go_read   = gpin_read,
+  .go_read   = gpout_read,
   .go_write  = gpout_write,
   .go_attach = NULL,
   .go_enable = NULL,
@@ -167,17 +167,31 @@ static int gpin_read(FAR struct gpio_dev_s *dev, FAR bool *value)
   FAR struct stm32gpio_dev_s *stm32gpio = (FAR struct stm32gpio_dev_s *)dev;
 
   DEBUGASSERT(stm32gpio != NULL && value != NULL);
+  DEBUGASSERT(stm32gpio->id < BOARD_NGPIOIN);
   gpioinfo("Reading...\n");
 
   *value = stm32_gpioread(g_gpioinputs[stm32gpio->id]);
   return OK;
 }
 
+static int gpout_read(FAR struct gpio_dev_s *dev, FAR bool *value)
+{
+  FAR struct stm32gpio_dev_s *stm32gpio = (FAR struct stm32gpio_dev_s *)dev;
+
+  DEBUGASSERT(stm32gpio != NULL && value != NULL);
+  DEBUGASSERT(stm32gpio->id < BOARD_NGPIOOUT);
+  gpioinfo("Reading...\n");
+
+  *value = stm32_gpioread(g_gpiooutputs[stm32gpio->id]);
+  return OK;
+}
+
 static int gpout_write(FAR struct gpio_dev_s *dev, bool value)
 {
   FAR struct stm32gpio_dev_s *stm32gpio = (FAR struct stm32gpio_dev_s *)dev;
 
   DEBUGASSERT(stm32gpio != NULL);
+  DEBUGASSERT(stm32gpio->id < BOARD_NGPIOOUT);
   gpioinfo("Writing %d\n", (int)value);
 
   stm32_gpiowrite(g_gpiooutputs[stm32gpio->id], value);