[1/3] ARM: OMAP1: ams-delta: assign MODEM IRQ from GPIO descriptor

Commit Message

Janusz Krzysztofik Aug. 20, 2018, 6:13 p.m. UTC

Don't request MODEM IRQ GPIO by its global number in
ams_delta_modem_init().  Instead, obtain its GPIO descriptor
and assign related IRQ to the MODEM.  Do that from
omap_gpio_deps_init(), where the chip is already looked up.  Then, in
ams_delta_modem_init(), just check for the IRQ number having been
already assigned.

Signed-off-by: Janusz Krzysztofik <[e-mail]>
---
 arch/arm/mach-omap1/board-ams-delta.c | 46 ++++++++++++++++++++++++++---------
 1 file changed, 35 insertions(+), 11 deletions(-)

Comments

Linus Walleij Aug. 23, 2018, 10:42 a.m. UTC | #1

On Mon, Aug 20, 2018 at 8:12 PM Janusz Krzysztofik <[e-mail]> wrote:

> Don't request MODEM IRQ GPIO by its global number in
> ams_delta_modem_init().  Instead, obtain its GPIO descriptor
> and assign related IRQ to the MODEM.  Do that from
> omap_gpio_deps_init(), where the chip is already looked up.  Then, in
> ams_delta_modem_init(), just check for the IRQ number having been
> already assigned.
>
> Signed-off-by: Janusz Krzysztofik <[e-mail]>

Reviewed-by: Linus Walleij <[e-mail]>

It's a bit unorthodox to have the board files intercept and poke
around inside the gpio_chip like the code in this file does,
I prefer to keep it encapsulated inside the GPIO driver.
However this is the lesser evil... if OMAP1 is ever phased
over to device tree it will go away, until then it is just nicely
contained.

Yours,
Linus Walleij

Patch

diff --git a/arch/arm/mach-omap1/board-ams-delta.c b/arch/arm/mach-omap1/board-ams-delta.c
index 34cb63ff45b3..b3fe515b6f49 100644
--- a/arch/arm/mach-omap1/board-ams-delta.c
+++ b/arch/arm/mach-omap1/board-ams-delta.c
@@ -630,6 +630,28 @@  static struct gpiod_hog ams_delta_gpio_hogs[] = {
 	{},
 };
 
+static struct plat_serial8250_port ams_delta_modem_ports[];
+
+/*
+ * Obtain MODEM IRQ GPIO descriptor using its hardware pin
+ * number and assign related IRQ number to the MODEM port.
+ * Keep the GPIO descriptor open so nobody steps in.
+ */
+static void __init modem_assign_irq(struct gpio_chip *chip)
+{
+	struct gpio_desc *gpiod;
+
+	gpiod = gpiochip_request_own_desc(chip, AMS_DELTA_GPIO_PIN_MODEM_IRQ,
+					  "modem_irq");
+	if (IS_ERR(gpiod)) {
+		pr_err("%s: modem IRQ GPIO request failed (%ld)\n", __func__,
+		       PTR_ERR(gpiod));
+	} else {
+		gpiod_direction_input(gpiod);
+		ams_delta_modem_ports[0].irq = gpiod_to_irq(gpiod);
+	}
+}
+
 /*
  * The purpose of this function is to take care of proper initialization of
  * devices and data structures which depend on GPIO lines provided by OMAP GPIO
@@ -649,7 +671,13 @@  static void __init omap_gpio_deps_init(void)
 		return;
 	}
 
+	/*
+	 * Start with FIQ initialization as it may have to request
+	 * and release successfully each OMAP GPIO pin in turn.
+	 */
 	ams_delta_init_fiq(chip, &ams_delta_serio_device);
+
+	modem_assign_irq(chip);
 }
 
 static void __init ams_delta_init(void)
@@ -844,20 +872,18 @@  static int __init modem_nreset_init(void)
 }
 
 
+/*
+ * This function expects MODEM IRQ number already assigned to the port
+ * and fails if it's not.
+ */
 static int __init ams_delta_modem_init(void)
 {
 	int err;
 
-	omap_cfg_reg(M14_1510_GPIO2);
-	ams_delta_modem_ports[0].irq =
-			gpio_to_irq(AMS_DELTA_GPIO_PIN_MODEM_IRQ);
+	if (ams_delta_modem_ports[0].irq < 0)
+		return ams_delta_modem_ports[0].irq;
 
-	err = gpio_request(AMS_DELTA_GPIO_PIN_MODEM_IRQ, "modem");
-	if (err) {
-		pr_err("Couldn't request gpio pin for modem\n");
-		return err;
-	}
-	gpio_direction_input(AMS_DELTA_GPIO_PIN_MODEM_IRQ);
+	omap_cfg_reg(M14_1510_GPIO2);
 
 	/* Initialize the modem_nreset regulator consumer before use */
 	modem_priv.regulator = ERR_PTR(-ENODEV);
@@ -866,8 +892,6 @@  static int __init ams_delta_modem_init(void)
 			AMS_DELTA_LATCH2_MODEM_CODEC);
 
 	err = platform_device_register(&ams_delta_modem_device);
-	if (err)
-		gpio_free(AMS_DELTA_GPIO_PIN_MODEM_IRQ);
 
 	return err;
 }