From 6d8e04f9d38345770572a39125a47da37bb8ce9e Mon Sep 17 00:00:00 2001
From: Martin DEVERA <devik@eaxlabs.cz>
Date: Wed, 5 Aug 2020 11:28:11 +0200
Subject: [PATCH] pinctrl: sx150x: Fix pinctrl enablement order bug
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I encountered bug in SX1502 expander driver in 5.7.7. Here is relevant
DTS part:

compatible = "semtech,sx1502q";
gpio4_cfg_pins: gpio2-cfg {
                         pins = "gpio5";
                         output-high;
     };

And part of OOPS:

[    0.673996] [<c023cfa6>] (gpiochip_get_data) from [<c023b235>]
(sx150x_gpio_direction_output+0xd)
[    0.683259] [<c023b235>] (sx150x_gpio_direction_output) from
[<c023b363>] (sx150x_pinconf_set+0x)
[    0.692796] [<c023b363>] (sx150x_pinconf_set) from [<c0238fef>]
(pinconf_apply_setting+0x39/0x7e)
[    0.701635] [<c0238fef>] (pinconf_apply_setting) from [<c0236c77>]
(pinctrl_commit_state+0xa5/0x)
[    0.710648] [<c0236c77>] (pinctrl_commit_state) from [<c0237e03>]
(pinctrl_enable+0xff/0x1d4)
[    0.719139] [<c0237e03>] (pinctrl_enable) from [<c023b791>]
(sx150x_probe+0x1a3/0x358)
[    0.727027] [<c023b791>] (sx150x_probe) from [<c02c38bf>]
(i2c_device_probe+0x1bb/0x1dc)

The problem is that sx150x_pinconf_set uses sx150x_gpio_direction_output
but gpio is not setup yet. Patch below fixes it but I'm not sure whether
is it correct.

Link: https://lore.kernel.org/r/f32130bf-cfd4-b1bf-538c-dbc9ee2d947a@eaxlabs.cz
Signed-off-by: Martin DEVERA <devik@eaxlabs.cz>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/pinctrl/pinctrl-sx150x.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-sx150x.c b/drivers/pinctrl/pinctrl-sx150x.c
index b325a13..c110f78 100644
--- a/drivers/pinctrl/pinctrl-sx150x.c
+++ b/drivers/pinctrl/pinctrl-sx150x.c
@@ -1154,12 +1154,6 @@ static int sx150x_probe(struct i2c_client *client,
 		return ret;
 	}
 
-	ret = pinctrl_enable(pctl->pctldev);
-	if (ret) {
-		dev_err(dev, "Failed to enable pinctrl device\n");
-		return ret;
-	}
-
 	/* Register GPIO controller */
 	pctl->gpio.base = -1;
 	pctl->gpio.ngpio = pctl->data->npins;
@@ -1238,6 +1232,17 @@ static int sx150x_probe(struct i2c_client *client,
 	if (ret)
 		return ret;
 
+	/*
+	 * Pin control functions need to be enabled AFTER registering the
+	 * GPIO chip because sx150x_pinconf_set() calls
+	 * sx150x_gpio_direction_output().
+	 */
+	ret = pinctrl_enable(pctl->pctldev);
+	if (ret) {
+		dev_err(dev, "Failed to enable pinctrl device\n");
+		return ret;
+	}
+
 	ret = gpiochip_add_pin_range(&pctl->gpio, dev_name(dev),
 				     0, 0, pctl->data->npins);
 	if (ret)
-- 
2.7.4