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From: Stephen Boyd <sboyd@codeaurora.org>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Timur Tabi <timur@codeaurora.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	linux-gpio@vger.kernel.org,
	Grant Likely <grant.likely@secretlab.ca>,
	devicetree@vger.kernel.org
Subject: [PATCH v2 1/3] dt-bindings: pinctrl: Add a reserved-gpio-ranges property
Date: Thu, 25 Jan 2018 17:13:58 -0800	[thread overview]
Message-ID: <20180126011400.2191-2-sboyd@codeaurora.org> (raw)
In-Reply-To: <20180126011400.2191-1-sboyd@codeaurora.org>

Some qcom platforms make some GPIOs or pins unavailable for use
by non-secure operating systems, and thus reading or writing the
registers for those pins will cause access control issues.
Introduce a DT property to describe the set of GPIOs that are
available for use so that higher level OSes are able to know what
pins to avoid reading/writing.

Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 Documentation/devicetree/bindings/gpio/gpio.txt | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index b5de08e3b1a2..c22b56680fc8 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -151,9 +151,9 @@ in a lot of designs, some using all 32 bits, some using 18 and some using
 first 18 GPIOs, at local offset 0 .. 17, are in use.
 
 If these GPIOs do not happen to be the first N GPIOs at offset 0...N-1, an
-additional bitmask is needed to specify which GPIOs are actually in use,
-and which are dummies. The bindings for this case has not yet been
-specified, but should be specified if/when such hardware appears.
+additional set of tuples is needed to specify which GPIOs are unusable, with
+the reserved-gpio-ranges binding. This property indicates the start and size
+of the GPIOs that can't be used.
 
 Optionally, a GPIO controller may have a "gpio-line-names" property. This is
 an array of strings defining the names of the GPIO lines going out of the
@@ -178,6 +178,7 @@ gpio-controller@00000000 {
 	gpio-controller;
 	#gpio-cells = <2>;
 	ngpios = <18>;
+	reserved-gpio-ranges = <0 4>, <12 2>;
 	gpio-line-names = "MMC-CD", "MMC-WP", "VDD eth", "RST eth", "LED R",
 		"LED G", "LED B", "Col A", "Col B", "Col C", "Col D",
 		"Row A", "Row B", "Row C", "Row D", "NMI button",
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

  reply	other threads:[~2018-01-26  1:14 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-26  1:13 [PATCH v2 0/3] Support qcom pinctrl protected pins Stephen Boyd
2018-01-26  1:13 ` Stephen Boyd [this message]
2018-01-26  9:20   ` [PATCH v2 1/3] dt-bindings: pinctrl: Add a reserved-gpio-ranges property Andy Shevchenko
2018-02-23 16:37   ` Bjorn Andersson
2018-03-20  3:36   ` Linus Walleij
2018-03-20  3:40     ` Timur Tabi
2018-03-20 21:35     ` Stephen Boyd
2018-01-26  1:13 ` [PATCH v2 2/3] gpiolib-of: Support 'reserved-gpio-ranges' property Stephen Boyd
2018-01-26  9:35   ` Andy Shevchenko
2018-02-07 13:34   ` Linus Walleij
2018-03-01 21:49     ` Stephen Boyd
2018-01-26  1:14 ` [PATCH v2 3/3] pinctrl: qcom: Don't allow protected pins to be requested Stephen Boyd
2018-02-20 16:45 ` [PATCH v2 0/3] Support qcom pinctrl protected pins Timur Tabi
2018-02-23 14:22   ` Linus Walleij
2018-02-23 16:54     ` Bjorn Andersson
2018-02-26 21:18       ` Timur Tabi

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