[PATCH v3 5/5] sh: mach-rsk: rsk7203: convert pin configuration to using software nodes

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Replace legacy gpio_request() calls used to configure function pins
(SCIF0 TXD/RXD and LAN9118 IRQ) with software nodes describing GPIO
hogs. These hogs are attached to the PFC gpiochip node, allowing the
GPIO subsystem to automatically configure these pins when the driver is
registered.

Assisted-by: LLM
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 arch/sh/boards/mach-rsk/devices-rsk7203.c | 103 ++++++++++++++++++++++++++----
 1 file changed, 91 insertions(+), 12 deletions(-)

diff --git a/arch/sh/boards/mach-rsk/devices-rsk7203.c b/arch/sh/boards/mach-rsk/devices-rsk7203.c
index 8076c9d15f87..7a2e73bb9645 100644
--- a/arch/sh/boards/mach-rsk/devices-rsk7203.c
+++ b/arch/sh/boards/mach-rsk/devices-rsk7203.c
@@ -12,7 +12,6 @@
 #include <linux/smsc911x.h>
 #include <linux/input.h>
 #include <linux/io.h>
-#include <linux/gpio.h>
 #include <linux/gpio/machine.h>
 #include <linux/gpio/property.h>
 #include <asm/machvec.h>
@@ -147,6 +146,62 @@ static const struct software_node rsk7203_sw3_key_node = {
 	.properties = rsk7203_sw3_key_props,
 };
 
+/* The base of the function GPIOs in the flat enum */
+#define SH7203_FN_BASE GPIO_FN_PINT7_PB
+
+static const struct software_node rsk7203_pfc_functions_node = {
+	.name = "functions",
+	.parent = &pfc_gpiochip_node,
+};
+
+static const struct property_entry rsk7203_txd0_hog_props[] = {
+	PROPERTY_ENTRY_BOOL("gpio-hog"),
+	PROPERTY_ENTRY_U32_ARRAY("gpios", ((u32[]){
+		GPIO_FN_TXD0 - SH7203_FN_BASE, GPIO_ACTIVE_HIGH
+	})),
+	PROPERTY_ENTRY_BOOL("input"),
+	PROPERTY_ENTRY_STRING("line-name", "TXD0"),
+	{ }
+};
+
+static const struct software_node rsk7203_txd0_hog_node = {
+	.name = "txd0-hog",
+	.parent = &rsk7203_pfc_functions_node,
+	.properties = rsk7203_txd0_hog_props,
+};
+
+static const struct property_entry rsk7203_rxd0_hog_props[] = {
+	PROPERTY_ENTRY_BOOL("gpio-hog"),
+	PROPERTY_ENTRY_U32_ARRAY("gpios", ((u32[]){
+		GPIO_FN_RXD0 - SH7203_FN_BASE, GPIO_ACTIVE_HIGH
+	})),
+	PROPERTY_ENTRY_BOOL("input"),
+	PROPERTY_ENTRY_STRING("line-name", "RXD0"),
+	{ }
+};
+
+static const struct software_node rsk7203_rxd0_hog_node = {
+	.name = "rxd0-hog",
+	.parent = &rsk7203_pfc_functions_node,
+	.properties = rsk7203_rxd0_hog_props,
+};
+
+static const struct property_entry rsk7203_irq0_hog_props[] = {
+	PROPERTY_ENTRY_BOOL("gpio-hog"),
+	PROPERTY_ENTRY_U32_ARRAY("gpios", ((u32[]){
+		GPIO_FN_IRQ0_PB - SH7203_FN_BASE, GPIO_ACTIVE_HIGH
+	})),
+	PROPERTY_ENTRY_BOOL("input"),
+	PROPERTY_ENTRY_STRING("line-name", "IRQ0_PB"),
+	{ }
+};
+
+static const struct software_node rsk7203_irq0_hog_node = {
+	.name = "irq0-hog",
+	.parent = &rsk7203_pfc_functions_node,
+	.properties = rsk7203_irq0_hog_props,
+};
+
 static const struct software_node * const rsk7203_swnodes[] __initconst = {
 	&rsk7203_gpio_leds_node,
 	&rsk7203_green_led_node,
@@ -157,6 +212,10 @@ static const struct software_node * const rsk7203_swnodes[] __initconst = {
 	&rsk7203_sw1_key_node,
 	&rsk7203_sw2_key_node,
 	&rsk7203_sw3_key_node,
+	&rsk7203_pfc_functions_node,
+	&rsk7203_txd0_hog_node,
+	&rsk7203_rxd0_hog_node,
+	&rsk7203_irq0_hog_node,
 	NULL
 };
 
@@ -181,26 +240,46 @@ static const struct platform_device_info rsk7203_devices[] __initconst = {
 	},
 };
 
-static int __init rsk7203_devices_setup(void)
+/*
+ * The pfc-sh7203 device is registered at arch_initcall level, and the
+ * sh-pfc driver (registered at postcore_initcall level) probes as soon
+ * as the device is created.
+ *
+ * We need to register our software nodes at postcore_initcall level so
+ * they are already present in the system when the driver probes and
+ * tries to apply GPIO hogs.
+ */
+static int __init rsk7203_sw_nodes_setup(void)
 {
-	struct platform_device *pd;
 	int error;
-	int i;
 
-	/* Select pins for SCIF0 */
-	gpio_request(GPIO_FN_TXD0, NULL);
-	gpio_request(GPIO_FN_RXD0, NULL);
-
-	/* Setup LAN9118: CS1 in 16-bit Big Endian Mode, IRQ0 at Port B */
-	__raw_writel(0x36db0400, 0xfffc0008); /* CS1BCR */
-	gpio_request(GPIO_FN_IRQ0_PB, NULL);
+	error = software_node_register(&pfc_gpiochip_node);
+	if (error && error != -EEXIST) {
+		pr_err("RSK7203: failed to register PFC software node: %d\n",
+		       error);
+		return error;
+	}
 
 	error = software_node_register_node_group(rsk7203_swnodes);
 	if (error) {
-		pr_err("failed to register software nodes: %d\n", error);
+		pr_err("RSK7203: failed to register board software nodes: %d\n",
+		       error);
 		return error;
 	}
 
+	return 0;
+}
+postcore_initcall(rsk7203_sw_nodes_setup);
+
+static int __init rsk7203_devices_setup(void)
+{
+	struct platform_device *pd;
+	int error;
+	int i;
+
+	/* Setup LAN9118: CS1 in 16-bit Big Endian Mode, IRQ0 at Port B */
+	__raw_writel(0x36db0400, 0xfffc0008); /* CS1BCR */
+
 	for (i = 0; i < ARRAY_SIZE(rsk7203_devices); i++) {
 		pd = platform_device_register_full(&rsk7203_devices[i]);
 		error = PTR_ERR_OR_ZERO(pd);

-- 
2.56.0.rc1.315.gc6ed9934b7-goog