dm: gpio: Add a way to update flags

It is convenient to be able to adjust some of the flags for a GPIO while
leaving others alone. Add a function for this.

Update dm_gpio_set_dir_flags() to make use of this.

Also update dm_gpio_set_value() to use this also, since this allows the
open-drain / open-source features to be implemented directly in the
driver, rather than using the uclass workaround.

Update the sandbox tests accordingly. This involves a lot of changes to
dm_test_gpio_opendrain_opensource() since we no-longer have the direciion
being reported differently depending on the open drain/open source flags.

Also update the STM32 drivers to let the uclass handle the active low/high
logic.

Drop the GPIOD_FLAGS_OUTPUT() macro which is no-longer used.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Tested-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Tested-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

5 files changed, 203 insertions, 43 deletions

diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 42479dba4da..eb8850dfe5c 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -569,6 +569,7 @@ int dm_gpio_get_value(const struct gpio_desc *desc)
 
 int dm_gpio_set_value(const struct gpio_desc *desc, int value)
 {
+	const struct dm_gpio_ops *ops;
 	int ret;
 
 	ret = check_reserved(desc, "set_value");
@@ -578,21 +579,33 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value)
 	if (desc->flags & GPIOD_ACTIVE_LOW)
 		value = !value;
 
+	/* GPIOD_ are directly managed by driver in set_flags */
+	ops = gpio_get_ops(desc->dev);
+	if (ops->set_flags) {
+		ulong flags = desc->flags;
+
+		if (value)
+			flags |= GPIOD_IS_OUT_ACTIVE;
+		else
+			flags &= ~GPIOD_IS_OUT_ACTIVE;
+		return ops->set_flags(desc->dev, desc->offset, flags);
+	}
+
 	/*
 	 * Emulate open drain by not actively driving the line high or
 	 * Emulate open source by not actively driving the line low
 	 */
 	if ((desc->flags & GPIOD_OPEN_DRAIN && value) ||
 	    (desc->flags & GPIOD_OPEN_SOURCE && !value))
-		return gpio_get_ops(desc->dev)->direction_input(desc->dev,
-								desc->offset);
+		return ops->direction_input(desc->dev, desc->offset);
 	else if (desc->flags & GPIOD_OPEN_DRAIN ||
 		 desc->flags & GPIOD_OPEN_SOURCE)
-		return gpio_get_ops(desc->dev)->direction_output(desc->dev,
-								desc->offset,
-								value);
+		return ops->direction_output(desc->dev, desc->offset, value);
+
+	ret = ops->set_value(desc->dev, desc->offset, value);
+	if (ret)
+		return ret;
 
-	gpio_get_ops(desc->dev)->set_value(desc->dev, desc->offset, value);
 	return 0;
 }
 
@@ -620,6 +633,17 @@ static int check_dir_flags(ulong flags)
 	return 0;
 }
 
+/**
+ * _dm_gpio_set_flags() - Send flags to the driver
+ *
+ * This uses the best available method to send the given flags to the driver.
+ * Note that if flags & GPIOD_ACTIVE_LOW, the driver sees the opposite value
+ * of GPIOD_IS_OUT_ACTIVE.
+ *
+ * @desc:	GPIO description
+ * @flags:	flags value to set
+ * @return 0 if OK, -ve on error
+ */
 static int _dm_gpio_set_flags(struct gpio_desc *desc, ulong flags)
 {
 	struct udevice *dev = desc->dev;
@@ -638,38 +662,52 @@ static int _dm_gpio_set_flags(struct gpio_desc *desc, ulong flags)
 		return ret;
 	}
 
+	/* If active low, invert the output state */
+	if ((flags & (GPIOD_IS_OUT | GPIOD_ACTIVE_LOW)) ==
+		(GPIOD_IS_OUT | GPIOD_ACTIVE_LOW))
+		flags ^= GPIOD_IS_OUT_ACTIVE;
+
 	/* GPIOD_ are directly managed by driver in set_flags */
 	if (ops->set_flags) {
 		ret = ops->set_flags(dev, desc->offset, flags);
 	} else {
 		if (flags & GPIOD_IS_OUT) {
-			ret = ops->direction_output(dev, desc->offset,
-						    GPIOD_FLAGS_OUTPUT(flags));
+			bool value = flags & GPIOD_IS_OUT_ACTIVE;
+
+			ret = ops->direction_output(dev, desc->offset, value);
 		} else if (flags & GPIOD_IS_IN) {
 			ret = ops->direction_input(dev, desc->offset);
 		}
 	}
 
-	/* save the flags also in descriptor */
-	if (!ret)
-		desc->flags = flags;
-
 	return ret;
 }
 
-int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
+int dm_gpio_clrset_flags(struct gpio_desc *desc, ulong clr, ulong set)
 {
+	ulong flags;
 	int ret;
 
 	ret = check_reserved(desc, "set_dir_flags");
 	if (ret)
 		return ret;
 
-	/* combine the requested flags (for IN/OUT) and the descriptor flags */
-	flags |= desc->flags;
+	flags = (desc->flags & ~clr) | set;
+
 	ret = _dm_gpio_set_flags(desc, flags);
+	if (ret)
+		return ret;
 
-	return ret;
+	/* save the flags also in descriptor */
+	desc->flags = flags;
+
+	return 0;
+}
+
+int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
+{
+	/* combine the requested flags (for IN/OUT) and the descriptor flags */
+	return dm_gpio_clrset_flags(desc, GPIOD_MASK_DIR, flags);
 }
 
 int dm_gpio_set_dir(struct gpio_desc *desc)
@@ -1011,7 +1049,10 @@ static int gpio_request_tail(int ret, const char *nodename,
 		debug("%s: dm_gpio_requestf failed\n", __func__);
 		goto err;
 	}
-	ret = dm_gpio_set_dir_flags(desc, flags);
+
+	/* Keep any direction flags provided by the devicetree */
+	ret = dm_gpio_set_dir_flags(desc,
+				    flags | (desc->flags & GPIOD_MASK_DIR));
 	if (ret) {
 		debug("%s: dm_gpio_set_dir failed\n", __func__);
 		goto err;
diff --git a/drivers/gpio/stm32_gpio.c b/drivers/gpio/stm32_gpio.c
index c2d7046c0dd..125c237551c 100644
--- a/drivers/gpio/stm32_gpio.c
+++ b/drivers/gpio/stm32_gpio.c
@@ -203,12 +203,13 @@ static int stm32_gpio_set_flags(struct udevice *dev, unsigned int offset,
 		return idx;
 
 	if (flags & GPIOD_IS_OUT) {
-		int value = GPIOD_FLAGS_OUTPUT(flags);
+		bool value = flags & GPIOD_IS_OUT_ACTIVE;
 
 		if (flags & GPIOD_OPEN_DRAIN)
 			stm32_gpio_set_otype(regs, idx, STM32_GPIO_OTYPE_OD);
 		else
 			stm32_gpio_set_otype(regs, idx, STM32_GPIO_OTYPE_PP);
+
 		stm32_gpio_set_moder(regs, idx, STM32_GPIO_MODE_OUT);
 		writel(BSRR_BIT(idx, value), &regs->bsrr);
 
diff --git a/drivers/pinctrl/pinctrl-stmfx.c b/drivers/pinctrl/pinctrl-stmfx.c
index 6ba56a16a3a..fe7a59d4313 100644
--- a/drivers/pinctrl/pinctrl-stmfx.c
+++ b/drivers/pinctrl/pinctrl-stmfx.c
@@ -169,6 +169,8 @@ static int stmfx_gpio_set_flags(struct udevice *dev, unsigned int offset,
 	int ret = -ENOTSUPP;
 
 	if (flags & GPIOD_IS_OUT) {
+		bool value = flags & GPIOD_IS_OUT_ACTIVE;
+
 		if (flags & GPIOD_OPEN_SOURCE)
 			return -ENOTSUPP;
 		if (flags & GPIOD_OPEN_DRAIN)
@@ -177,8 +179,7 @@ static int stmfx_gpio_set_flags(struct udevice *dev, unsigned int offset,
 			ret = stmfx_conf_set_type(dev, offset, 1);
 		if (ret)
 			return ret;
-		ret = stmfx_gpio_direction_output(dev, offset,
-						  GPIOD_FLAGS_OUTPUT(flags));
+		ret = stmfx_gpio_direction_output(dev, offset, value);
 	} else if (flags & GPIOD_IS_IN) {
 		ret = stmfx_gpio_direction_input(dev, offset);
 		if (ret)
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 4f8d1938da9..7d1e19ad531 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -128,6 +128,12 @@ struct gpio_desc {
 #define GPIOD_PULL_UP		BIT(7)	/* GPIO has pull-up enabled */
 #define GPIOD_PULL_DOWN		BIT(8)	/* GPIO has pull-down enabled */
 
+/* Flags for updating the above */
+#define GPIOD_MASK_DIR		(GPIOD_IS_OUT | GPIOD_IS_IN | \
+					GPIOD_IS_OUT_ACTIVE)
+#define GPIOD_MASK_DSTYPE	(GPIOD_OPEN_DRAIN | GPIOD_OPEN_SOURCE)
+#define GPIOD_MASK_PULL		(GPIOD_PULL_UP | GPIOD_PULL_DOWN)
+
 	uint offset;		/* GPIO offset within the device */
 	/*
 	 * We could consider adding the GPIO label in here. Possibly we could
@@ -135,12 +141,6 @@ struct gpio_desc {
 	 */
 };
 
-/* helper to compute the value of the gpio output */
-#define GPIOD_FLAGS_OUTPUT_MASK (GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE)
-#define GPIOD_FLAGS_OUTPUT(flags) \
-	(((((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_IS_OUT_ACTIVE) || \
-	  (((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_ACTIVE_LOW)))
-
 /**
  * dm_gpio_is_valid() - Check if a GPIO is valid
  *
@@ -669,6 +669,25 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value);
 int dm_gpio_set_dir(struct gpio_desc *desc);
 
 /**
+ * dm_gpio_clrset_flags() - Update flags
+ *
+ * This updates the flags as directled. Note that desc->flags is updated by this
+ * function on success. If any changes cannot be made, best efforts are made.
+ *
+ * By use of @clr and @set any of flags can be individually updated, or left
+ * alone
+ *
+ * @desc:	GPIO description containing device, offset and flags,
+ *		previously returned by gpio_request_by_name()
+ * @clr:	Flags to clear (GPIOD_...)
+ * @set:	Flags to set (GPIOD_...)
+ * @return 0 if OK, -EINVAL if the flags had obvious conflicts,
+ * -ERECALLCONFLICT if there was a non-obvious hardware conflict when attempting
+ * to set the flags
+ */
+int dm_gpio_clrset_flags(struct gpio_desc *desc, ulong clr, ulong set);
+
+/**
  * dm_gpio_set_dir_flags() - Set direction using description and added flags
  *
  * This sets up the direction according to the provided flags and the GPIO
diff --git a/test/dm/gpio.c b/test/dm/gpio.c
index dfbb634bf71..be5da953045 100644
--- a/test/dm/gpio.c
+++ b/test/dm/gpio.c
@@ -178,15 +178,15 @@ static int dm_test_gpio_opendrain_opensource(struct unit_test_state *uts)
 	ut_asserteq(GPIOD_IS_OUT | GPIOD_OPEN_DRAIN,
 		    sandbox_gpio_get_flags(gpio_c, 0));
 
-	/* Set it as output high, should become an input */
+	/* Set it as output high */
 	ut_assertok(dm_gpio_set_value(&desc_list[0], 1));
-	ut_assertok(gpio_get_status(gpio_c, 0, buf, sizeof(buf)));
-	ut_asserteq_str("c0: input: 0 [x] a-test.test3-gpios0", buf);
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_OPEN_DRAIN | GPIOD_IS_OUT_ACTIVE,
+		    sandbox_gpio_get_flags(gpio_c, 0));
 
-	/* Set it as output low, should become output low */
+	/* Set it as output low */
 	ut_assertok(dm_gpio_set_value(&desc_list[0], 0));
-	ut_assertok(gpio_get_status(gpio_c, 0, buf, sizeof(buf)));
-	ut_asserteq_str("c0: output: 0 [x] a-test.test3-gpios0", buf);
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_OPEN_DRAIN,
+		    sandbox_gpio_get_flags(gpio_c, 0));
 
 	/* GPIO 1 is (GPIO_OUT|GPIO_OPEN_SOURCE) */
 	ut_asserteq(GPIOD_IS_OUT | GPIOD_OPEN_SOURCE,
@@ -197,13 +197,21 @@ static int dm_test_gpio_opendrain_opensource(struct unit_test_state *uts)
 	ut_assertok(gpio_get_status(gpio_c, 1, buf, sizeof(buf)));
 	ut_asserteq_str("c1: output: 1 [x] a-test.test3-gpios1", buf);
 
-	/* Set it as output low, should become an input */
+	/* Set it as output low */
 	ut_assertok(dm_gpio_set_value(&desc_list[1], 0));
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_OPEN_SOURCE,
+		    sandbox_gpio_get_flags(gpio_c, 1));
+
 	ut_assertok(gpio_get_status(gpio_c, 1, buf, sizeof(buf)));
-	ut_asserteq_str("c1: input: 1 [x] a-test.test3-gpios1", buf);
+	ut_asserteq_str("c1: output: 0 [x] a-test.test3-gpios1", buf);
 
-	/* GPIO 6 is (GPIO_ACTIVE_LOW|GPIO_OUT|GPIO_OPEN_DRAIN) */
-	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_DRAIN,
+	/*
+	 * GPIO 6 is (GPIO_ACTIVE_LOW|GPIO_OUT|GPIO_OPEN_DRAIN). Looking at it
+	 * directlt from the driver, we get GPIOD_IS_OUT_ACTIVE also, since it
+	 * is active low
+	 */
+	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_DRAIN |
+		    GPIOD_IS_OUT_ACTIVE,
 		    sandbox_gpio_get_flags(gpio_c, 6));
 
 	/* Set it as output high, should become output low */
@@ -211,19 +219,21 @@ static int dm_test_gpio_opendrain_opensource(struct unit_test_state *uts)
 	ut_assertok(gpio_get_status(gpio_c, 6, buf, sizeof(buf)));
 	ut_asserteq_str("c6: output: 0 [x] a-test.test3-gpios6", buf);
 
-	/* Set it as output low, should become an input */
+	/* Set it as output low */
 	ut_assertok(dm_gpio_set_value(&desc_list[6], 0));
-	ut_assertok(gpio_get_status(gpio_c, 6, buf, sizeof(buf)));
-	ut_asserteq_str("c6: input: 0 [x] a-test.test3-gpios6", buf);
+	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_DRAIN |
+		    GPIOD_IS_OUT_ACTIVE,
+		    sandbox_gpio_get_flags(gpio_c, 6));
 
 	/* GPIO 7 is (GPIO_ACTIVE_LOW|GPIO_OUT|GPIO_OPEN_SOURCE) */
-	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_SOURCE,
+	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_SOURCE |
+		    GPIOD_IS_OUT_ACTIVE,
 		    sandbox_gpio_get_flags(gpio_c, 7));
 
-	/* Set it as output high, should become an input */
+	/* Set it as output high */
 	ut_assertok(dm_gpio_set_value(&desc_list[7], 1));
-	ut_assertok(gpio_get_status(gpio_c, 7, buf, sizeof(buf)));
-	ut_asserteq_str("c7: input: 0 [x] a-test.test3-gpios7", buf);
+	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_SOURCE,
+		    sandbox_gpio_get_flags(gpio_c, 7));
 
 	/* Set it as output low, should become output high */
 	ut_assertok(dm_gpio_set_value(&desc_list[7], 0));
@@ -582,3 +592,91 @@ static int dm_test_gpio_devm(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_gpio_devm, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+
+static int dm_test_clrset_flags(struct unit_test_state *uts)
+{
+	struct gpio_desc desc;
+	struct udevice *dev;
+	ulong flags;
+
+	ut_assertok(uclass_get_device(UCLASS_TEST_FDT, 0, &dev));
+	ut_asserteq_str("a-test", dev->name);
+	ut_assertok(gpio_request_by_name(dev, "test-gpios", 1, &desc, 0));
+
+	ut_assertok(dm_gpio_clrset_flags(&desc, GPIOD_MASK_DIR, GPIOD_IS_OUT));
+	ut_assertok(dm_gpio_get_flags(&desc, &flags));
+	ut_asserteq(GPIOD_IS_OUT, flags);
+	ut_asserteq(GPIOD_IS_OUT, desc.flags);
+	ut_asserteq(0, sandbox_gpio_get_value(desc.dev, desc.offset));
+
+	ut_assertok(dm_gpio_clrset_flags(&desc, 0, GPIOD_IS_OUT_ACTIVE));
+	ut_assertok(dm_gpio_get_flags(&desc, &flags));
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE, flags);
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE, desc.flags);
+	ut_asserteq(1, sandbox_gpio_get_value(desc.dev, desc.offset));
+	ut_asserteq(1, dm_gpio_get_value(&desc));
+
+	ut_assertok(dm_gpio_clrset_flags(&desc, GPIOD_MASK_DIR, GPIOD_IS_IN));
+	ut_assertok(dm_gpio_get_flags(&desc, &flags));
+	ut_asserteq(GPIOD_IS_IN, flags & GPIOD_MASK_DIR);
+	ut_asserteq(GPIOD_IS_IN, desc.flags & GPIOD_MASK_DIR);
+
+	ut_assertok(dm_gpio_clrset_flags(&desc, GPIOD_MASK_PULL,
+					 GPIOD_PULL_UP));
+	ut_assertok(dm_gpio_get_flags(&desc, &flags));
+	ut_asserteq(GPIOD_IS_IN | GPIOD_PULL_UP, flags);
+	ut_asserteq(GPIOD_IS_IN | GPIOD_PULL_UP, desc.flags);
+
+	/* Check we cannot set both PULL_UP and PULL_DOWN */
+	ut_asserteq(-EINVAL, dm_gpio_clrset_flags(&desc, 0, GPIOD_PULL_DOWN));
+
+	return 0;
+}
+DM_TEST(dm_test_clrset_flags, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+
+/* Check that an active-low GPIO works as expected */
+static int dm_test_clrset_flags_invert(struct unit_test_state *uts)
+{
+	struct gpio_desc desc;
+	struct udevice *dev;
+	ulong flags;
+
+	ut_assertok(uclass_get_device(UCLASS_TEST_FDT, 0, &dev));
+	ut_asserteq_str("a-test", dev->name);
+	ut_assertok(gpio_request_by_name(dev, "test-gpios", 1, &desc,
+					 GPIOD_IS_OUT | GPIOD_ACTIVE_LOW));
+
+	/*
+	 * From this size we see it as 0 (active low), but the sandbox driver
+	 * sees the pin value high
+	 */
+	ut_asserteq(0, dm_gpio_get_value(&desc));
+	ut_asserteq(1, sandbox_gpio_get_value(desc.dev, desc.offset));
+
+	ut_assertok(dm_gpio_set_value(&desc, 1));
+	ut_asserteq(1, dm_gpio_get_value(&desc));
+	ut_asserteq(0, sandbox_gpio_get_value(desc.dev, desc.offset));
+
+	/* Do the same with dm_gpio_clrset_flags() */
+	ut_assertok(dm_gpio_clrset_flags(&desc, GPIOD_IS_OUT_ACTIVE, 0));
+	ut_asserteq(0, dm_gpio_get_value(&desc));
+	ut_asserteq(1, sandbox_gpio_get_value(desc.dev, desc.offset));
+
+	ut_assertok(dm_gpio_clrset_flags(&desc, 0, GPIOD_IS_OUT_ACTIVE));
+	ut_asserteq(1, dm_gpio_get_value(&desc));
+	ut_asserteq(0, sandbox_gpio_get_value(desc.dev, desc.offset));
+
+	ut_assertok(dm_gpio_get_flags(&desc, &flags));
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE,
+		    flags);
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE,
+		    desc.flags);
+
+	ut_assertok(dm_gpio_clrset_flags(&desc, GPIOD_IS_OUT_ACTIVE, 0));
+	ut_assertok(dm_gpio_get_flags(&desc, &flags));
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_ACTIVE_LOW, flags);
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_ACTIVE_LOW, desc.flags);
+
+	return 0;
+}
+DM_TEST(dm_test_clrset_flags_invert, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);