[PATCH 1/4] ARM: bcm2835 mbox: Remove response valid check

[PATCH 1/4] ARM: bcm2835 mbox: Remove response valid check

[Sascha Hauer]

Not all messages return a valid response as they do not send a response
at all. This is at least true for the SET_GPIO_STATE and SET_GPIO_CONFIG
messages.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/mach-bcm283x/mbox.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/arch/arm/mach-bcm283x/mbox.c b/arch/arm/mach-bcm283x/mbox.c
index b295993359..4405efaffd 100644
--- a/arch/arm/mach-bcm283x/mbox.c
+++ b/arch/arm/mach-bcm283x/mbox.c
@@ -137,11 +137,6 @@ int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer)
 	tag = (void *)(buffer + 1);
 	tag_index = 0;
 	while (tag->tag) {
-		if (!(tag->val_len & BCM2835_MBOX_TAG_VAL_LEN_RESPONSE)) {
-			printf("mbox: Tag %d missing val_len response bit\n",
-				tag_index);
-			return -EIO;
-		}
 		/*
 		 * Clear the reponse bit so clients can just look right at the
 		 * length field without extra processing
-- 
2.24.0


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[PATCH 2/4] gpio: Add raspberrypi exp gpio driver

[Sascha Hauer]

Taken from the kernel adopted to barebox.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/mach-bcm283x/include/mach/mbox.h |   4 +
 drivers/gpio/Kconfig                      |   7 +
 drivers/gpio/Makefile                     |   1 +
 drivers/gpio/gpio-raspberrypi-exp.c       | 273 ++++++++++++++++++++++
 4 files changed, 285 insertions(+)
 create mode 100644 drivers/gpio/gpio-raspberrypi-exp.c

diff --git a/arch/arm/mach-bcm283x/include/mach/mbox.h b/arch/arm/mach-bcm283x/include/mach/mbox.h
index 6db961b807..f10f5bc148 100644
--- a/arch/arm/mach-bcm283x/include/mach/mbox.h
+++ b/arch/arm/mach-bcm283x/include/mach/mbox.h
@@ -126,6 +126,10 @@ struct bcm2835_mbox_tag_hdr {
  */
 
 #define BCM2835_MBOX_TAG_GET_BOARD_REV	0x00010002
+#define BCM2835_MBOX_TAG_GET_GPIO_STATE 0x00030041
+#define BCM2835_MBOX_TAG_SET_GPIO_STATE 0x00038041
+#define BCM2835_MBOX_TAG_GET_GPIO_CONFIG 0x00030043
+#define BCM2835_MBOX_TAG_SET_GPIO_CONFIG 0x00038043
 
 /*
  * ids
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 0f924d135f..7e4fc90d39 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -129,6 +129,13 @@ config GPIO_PL061
 	help
 	  Say yes here to support the PrimeCell PL061 GPIO device
 
+config GPIO_RASPBERRYPI_EXP
+	bool "Raspberry Pi 3 GPIO Expander"
+	depends on ARCH_BCM283X
+	help
+	  Turn on GPIO support for the expander on Raspberry Pi 3 boards, using
+	  the firmware mailbox to communicate with VideoCore on BCM283x chips.
+
 config GPIO_STMPE
 	depends on MFD_STMPE
 	bool "STMPE GPIO Expander"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index bc5c500e4d..77dcf58f64 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_GPIO_TEGRA)	+= gpio-tegra.o
 obj-$(CONFIG_GPIO_DESIGNWARE)	+= gpio-dw.o
 obj-$(CONFIG_GPIO_SX150X)	+= gpio-sx150x.o
 obj-$(CONFIG_GPIO_VF610)	+= gpio-vf610.o
+obj-$(CONFIG_GPIO_RASPBERRYPI_EXP) += gpio-raspberrypi-exp.o
diff --git a/drivers/gpio/gpio-raspberrypi-exp.c b/drivers/gpio/gpio-raspberrypi-exp.c
new file mode 100644
index 0000000000..f03a2a2579
--- /dev/null
+++ b/drivers/gpio/gpio-raspberrypi-exp.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Raspberry Pi 3 expander GPIO driver
+ *
+ *  Uses the firmware mailbox service to communicate with the
+ *  GPIO expander on the VPU.
+ *
+ *  Copyright (C) 2017 Raspberry Pi Trading Ltd.
+ */
+
+#include <common.h>
+#include <gpio.h>
+#include <init.h>
+#include <mach/mbox.h>
+
+#define NUM_GPIO 8
+
+#define RPI_EXP_GPIO_BASE	128
+
+#define RPI_EXP_GPIO_DIR_IN	0
+#define RPI_EXP_GPIO_DIR_OUT	1
+
+struct rpi_exp_gpio {
+	struct gpio_chip gc;
+	struct rpi_firmware *fw;
+};
+
+/* VC4 firmware mailbox interface data structures */
+struct gpio_set_config {
+	struct bcm2835_mbox_hdr hdr;		/* buf_size, code */
+	struct bcm2835_mbox_tag_hdr tag_hdr;	/* tag, val_buf_size, val_len */
+        union {
+                struct {
+			u32 gpio;
+			u32 direction;
+			u32 polarity;
+			u32 term_en;
+			u32 term_pull_up;
+			u32 state;
+                } req;
+	} body;
+	u32 end_tag;
+};
+
+struct gpio_get_config {
+	struct bcm2835_mbox_hdr hdr;
+	struct bcm2835_mbox_tag_hdr tag_hdr;
+        union {
+                struct {
+			u32 gpio;
+			u32 direction;
+			u32 polarity;
+			u32 term_en;
+			u32 term_pull_up;
+                } req;
+	} body;
+	u32 end_tag;
+};
+
+struct gpio_get_set_state {
+	struct bcm2835_mbox_hdr hdr;
+	struct bcm2835_mbox_tag_hdr tag_hdr;
+        union {
+                struct {
+			u32 gpio;
+			u32 state;
+                } req;
+	} body;
+	u32 end_tag;
+};
+
+static inline struct rpi_exp_gpio *to_rpi_gpio(struct gpio_chip *gc)
+{
+	return container_of(gc, struct rpi_exp_gpio, gc);
+}
+
+static int rpi_exp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off)
+{
+	struct rpi_exp_gpio *gpio;
+	int ret;
+	BCM2835_MBOX_STACK_ALIGN(struct gpio_get_config, get);
+	BCM2835_MBOX_INIT_HDR(get);
+	BCM2835_MBOX_INIT_TAG(get, GET_GPIO_CONFIG);
+
+	gpio = to_rpi_gpio(gc);
+
+	get->body.req.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &get->hdr);
+	if (ret || get->body.req.gpio != 0) {
+		dev_err(gc->dev, "Failed to get GPIO %u config (%d %x)\n",
+			off, ret, get->body.req.gpio);
+		return ret ? ret : -EIO;
+	}
+	return get->body.req.polarity;
+}
+
+static int rpi_exp_gpio_dir_in(struct gpio_chip *gc, unsigned int off)
+{
+	struct rpi_exp_gpio *gpio;
+	int ret;
+	BCM2835_MBOX_STACK_ALIGN(struct gpio_set_config, set_in);
+	BCM2835_MBOX_INIT_HDR(set_in);
+	BCM2835_MBOX_INIT_TAG(set_in, SET_GPIO_CONFIG);
+
+	gpio = to_rpi_gpio(gc);
+
+	set_in->body.req.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
+	set_in->body.req.direction = RPI_EXP_GPIO_DIR_IN;
+	set_in->body.req.term_en = 0;		/* termination disabled */
+	set_in->body.req.term_pull_up = 0;	/* n/a as termination disabled */
+	set_in->body.req.state = 0;		/* n/a as configured as an input */
+
+	ret = rpi_exp_gpio_get_polarity(gc, off);
+	if (ret < 0)
+		return ret;
+
+	set_in->body.req.polarity = ret;		/* Retain existing setting */
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &set_in->hdr);
+	if (ret || set_in->body.req.gpio != 0) {
+		dev_err(gc->dev, "Failed to set GPIO %u to input (%d %x)\n",
+			off, ret, set_in->body.req.gpio);
+		return ret ? ret : -EIO;
+	}
+
+	return 0;
+}
+
+static int rpi_exp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val)
+{
+	struct rpi_exp_gpio *gpio;
+	int ret;
+	BCM2835_MBOX_STACK_ALIGN(struct gpio_set_config, set_out);
+	BCM2835_MBOX_INIT_HDR(set_out);
+	BCM2835_MBOX_INIT_TAG(set_out, SET_GPIO_CONFIG);
+
+	gpio = to_rpi_gpio(gc);
+
+	set_out->body.req.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
+	set_out->body.req.direction = RPI_EXP_GPIO_DIR_OUT;
+	set_out->body.req.term_en = 0;		/* n/a as an output */
+	set_out->body.req.term_pull_up = 0;	/* n/a as termination disabled */
+	set_out->body.req.state = val;		/* Output state */
+
+	ret = rpi_exp_gpio_get_polarity(gc, off);
+	if (ret < 0)
+		return ret;
+	set_out->body.req.polarity = ret;		/* Retain existing setting */
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &set_out->hdr);
+	if (ret || set_out->body.req.gpio != 0) {
+		dev_err(gc->dev, "Failed to set GPIO %u to output (%d %x)\n",
+			off, ret, set_out->body.req.gpio);
+		return ret ? ret : -EIO;
+	}
+	return 0;
+}
+
+static int rpi_exp_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
+{
+	struct rpi_exp_gpio *gpio;
+	int ret;
+	BCM2835_MBOX_STACK_ALIGN(struct gpio_get_config, get);
+	BCM2835_MBOX_INIT_HDR(get);
+	BCM2835_MBOX_INIT_TAG(get, GET_GPIO_CONFIG);
+
+	gpio = to_rpi_gpio(gc);
+
+	get->body.req.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &get->hdr);
+	if (ret || get->body.req.gpio != 0) {
+		dev_err(gc->dev,
+			"Failed to get GPIO %u config (%d %x)\n", off, ret,
+			get->body.req.gpio);
+		return ret ? ret : -EIO;
+	}
+	if (get->body.req.direction)
+		return GPIOF_DIR_OUT;
+
+	return GPIOF_DIR_IN;
+}
+
+static int rpi_exp_gpio_get(struct gpio_chip *gc, unsigned int off)
+{
+	struct rpi_exp_gpio *gpio;
+	int ret;
+	BCM2835_MBOX_STACK_ALIGN(struct gpio_get_set_state, get);
+	BCM2835_MBOX_INIT_HDR(get);
+	BCM2835_MBOX_INIT_TAG(get, GET_GPIO_STATE);
+
+	gpio = to_rpi_gpio(gc);
+
+	get->body.req.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
+	get->body.req.state = 0;		/* storage for returned value */
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &get->hdr);
+	if (ret || get->body.req.gpio != 0) {
+		dev_err(gc->dev,
+			"Failed to get GPIO %u state (%d %x)\n", off, ret,
+			get->body.req.gpio);
+		return ret ? ret : -EIO;
+	}
+	return !!get->body.req.state;
+}
+
+static void rpi_exp_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
+{
+	struct rpi_exp_gpio *gpio;
+	int ret;
+	BCM2835_MBOX_STACK_ALIGN(struct gpio_get_set_state, set);
+	BCM2835_MBOX_INIT_HDR(set);
+	BCM2835_MBOX_INIT_TAG(set, SET_GPIO_STATE);
+
+	gpio = to_rpi_gpio(gc);
+
+	set->body.req.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
+	set->body.req.state = val;	/* Output state */
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &set->hdr);
+	if (ret || set->body.req.gpio != 0)
+		dev_err(gc->dev,
+			"Failed to set GPIO %u state (%d %x)\n", off, ret,
+			set->body.req.gpio);
+}
+
+static struct gpio_ops rpi_exp_gpio_ops = {
+	.direction_input = rpi_exp_gpio_dir_in,
+	.direction_output = rpi_exp_gpio_dir_out,
+	.get_direction = rpi_exp_gpio_get_direction,
+	.get = rpi_exp_gpio_get,
+	.set = rpi_exp_gpio_set,
+};
+
+static int rpi_exp_gpio_probe(struct device_d *dev)
+{
+	struct device_node *np = dev->device_node;
+	struct rpi_exp_gpio *rpi_gpio;
+	int ret;
+
+	rpi_gpio = xzalloc(sizeof(*rpi_gpio));
+
+	rpi_gpio->gc.dev = dev;
+	rpi_gpio->gc.base = -1;
+	rpi_gpio->gc.ngpio = NUM_GPIO;
+	rpi_gpio->gc.ops = &rpi_exp_gpio_ops;
+
+	ret = gpiochip_add(&rpi_gpio->gc);
+	if (ret)
+		return ret;
+
+	dev_dbg(dev, "probed gpiochip with %d gpios, base %d\n",
+			rpi_gpio->gc.ngpio, rpi_gpio->gc.base);
+
+	return 0;
+}
+
+static __maybe_unused struct of_device_id rpi_exp_gpio_ids[] = {
+	{
+		.compatible = "raspberrypi,firmware-gpio",
+	}, {
+		/* sentinel */
+	},
+};
+
+static struct driver_d rpi_exp_gpio_driver = {
+	.name = "dw-apb-gpio",
+	.probe = rpi_exp_gpio_probe,
+	.of_compatible = DRV_OF_COMPAT(rpi_exp_gpio_ids),
+};
+
+device_platform_driver(rpi_exp_gpio_driver);
-- 
2.24.0


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[PATCH 3/4] ARM: bcm2835 mbox: use pr_* to print messages

[Sascha Hauer]

To give the user an idea where the messages come from.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/mach-bcm283x/mbox.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/arch/arm/mach-bcm283x/mbox.c b/arch/arm/mach-bcm283x/mbox.c
index 4405efaffd..1b1981f7cb 100644
--- a/arch/arm/mach-bcm283x/mbox.c
+++ b/arch/arm/mach-bcm283x/mbox.c
@@ -6,6 +6,8 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+#define pr_fmt(fmt) "rpi-mbox: " fmt
+
 #include <clock.h>
 #include <common.h>
 #include <dma.h>
@@ -26,7 +28,7 @@ static int bcm2835_mbox_call_raw(u32 chan, struct bcm2835_mbox_hdr *buffer,
 	u32 val;
 
 	if (send & BCM2835_CHAN_MASK) {
-		printf("mbox: Illegal mbox data 0x%08x\n", send);
+		pr_err("mbox: Illegal mbox data 0x%08x\n", send);
 		return -EINVAL;
 	}
 
@@ -36,7 +38,7 @@ static int bcm2835_mbox_call_raw(u32 chan, struct bcm2835_mbox_hdr *buffer,
 		if (val & BCM2835_MBOX_STATUS_RD_EMPTY)
 			break;
 		if (is_timeout(starttime, TIMEOUT)) {
-			printf("mbox: Timeout draining stale responses\n");
+			pr_err("mbox: Timeout draining stale responses\n");
 			return -ETIMEDOUT;
 		}
 		val = readl(mbox_base + MAIL0_RD);
@@ -48,14 +50,14 @@ static int bcm2835_mbox_call_raw(u32 chan, struct bcm2835_mbox_hdr *buffer,
 		if (!(val & BCM2835_MBOX_STATUS_WR_FULL))
 			break;
 		if (is_timeout(starttime, TIMEOUT)) {
-			printf("mbox: Timeout waiting for send space\n");
+			pr_err("mbox: Timeout waiting for send space\n");
 			return -ETIMEDOUT;
 		}
 	}
 
 	/* Send the request */
 	val = BCM2835_MBOX_PACK(chan, send);
-	debug("mbox: TX raw: 0x%08x\n", val);
+	pr_debug("mbox: TX raw: 0x%08x\n", val);
 	dma_sync_single_for_device((unsigned long)send, buffer->buf_size,
 				   DMA_BIDIRECTIONAL);
 	writel(val, mbox_base + MAIL1_WRT);
@@ -66,20 +68,20 @@ static int bcm2835_mbox_call_raw(u32 chan, struct bcm2835_mbox_hdr *buffer,
 		if (!(val & BCM2835_MBOX_STATUS_RD_EMPTY))
 			break;
 		if (is_timeout(starttime, TIMEOUT)) {
-			printf("mbox: Timeout waiting for response\n");
+			pr_err("mbox: Timeout waiting for response\n");
 			return -ETIMEDOUT;
 		}
 	}
 
 	/* Read the response */
 	val = readl(mbox_base + MAIL0_RD);
-	debug("mbox: RX raw: 0x%08x\n", val);
+	pr_debug("mbox: RX raw: 0x%08x\n", val);
 	dma_sync_single_for_cpu((unsigned long)send, buffer->buf_size,
 				DMA_BIDIRECTIONAL);
 
 	/* Validate the response */
 	if (BCM2835_MBOX_UNPACK_CHAN(val) != chan) {
-		printf("mbox: Response channel mismatch\n");
+		pr_err("mbox: Response channel mismatch\n");
 		return -EIO;
 	}
 
@@ -89,7 +91,7 @@ static int bcm2835_mbox_call_raw(u32 chan, struct bcm2835_mbox_hdr *buffer,
 }
 
 #ifdef DEBUG
-void dump_buf(struct bcm2835_mbox_hdr *buffer)
+static void dump_buf(struct bcm2835_mbox_hdr *buffer)
 {
 	u32 *p;
 	u32 words;
@@ -98,7 +100,11 @@ void dump_buf(struct bcm2835_mbox_hdr *buffer)
 	p = (u32 *)buffer;
 	words = buffer->buf_size / 4;
 	for (i = 0; i < words; i++)
-		printf("    0x%04x: 0x%08x\n", i * 4, p[i]);
+		pr_debug("    0x%04x: 0x%08x\n", i * 4, p[i]);
+}
+#else
+static void dump_buf(struct bcm2835_mbox_hdr *buffer)
+{
 }
 #endif
 
@@ -109,27 +115,23 @@ int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer)
 	struct bcm2835_mbox_tag_hdr *tag;
 	int tag_index;
 
-#ifdef DEBUG
-	printf("mbox: TX buffer\n");
+	pr_debug("mbox: TX buffer\n");
 	dump_buf(buffer);
-#endif
 
 	ret = bcm2835_mbox_call_raw(chan, buffer, &rbuffer);
 	if (ret)
 		return ret;
 	if (rbuffer != (u32)buffer) {
-		printf("mbox: Response buffer mismatch\n");
+		pr_err("mbox: Response buffer mismatch\n");
 		return -EIO;
 	}
 
-#ifdef DEBUG
-	printf("mbox: RX buffer\n");
+	pr_debug("mbox: RX buffer\n");
 	dump_buf(buffer);
-#endif
 
 	/* Validate overall response status */
 	if (buffer->code != BCM2835_MBOX_RESP_CODE_SUCCESS) {
-		printf("mbox: Header response code invalid\n");
+		pr_err("mbox: Header response code invalid\n");
 		return -EIO;
 	}
 
-- 
2.24.0


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[PATCH 4/4] ARM: rpi_defconfig: Enable raspberry GPIO exp driver

[Sascha Hauer]

Enable the recently introduced GPIO exp driver.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/configs/rpi_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/rpi_defconfig b/arch/arm/configs/rpi_defconfig
index 9603a0fa30..560b3d1b11 100644
--- a/arch/arm/configs/rpi_defconfig
+++ b/arch/arm/configs/rpi_defconfig
@@ -83,6 +83,7 @@ CONFIG_LED_GPIO=y
 CONFIG_LED_TRIGGERS=y
 CONFIG_WATCHDOG=y
 CONFIG_WATCHDOG_BCM2835=y
+CONFIG_GPIO_RASPBERRYPI_EXP=y
 CONFIG_PINCTRL_BCM283X=y
 CONFIG_REGULATOR=y
 CONFIG_FS_EXT4=y
-- 
2.24.0


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