coreboot-kgpe-d16/src/lib/tristate_gpios.c

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Generalize revision number calculation function Some platforms use tertiary interpretation of GPIO input state to increase number of distinct values represented by a limited number of GPIOs. The three states are - external pull down (interpreted as 0) - external pull up (1) - not connected (2) This has been required by Nvidia devices so far, but Exynos and Ipq8086 platforms need this too. This patch moves the function reading the tertiary state into the library and exposes the necessary GPIO API functions in a new include file. The functions are still supposed to be provided by platform specific modules. The function interpreting the GPIO states has been modified to allow to interpret the state either as a true tertiary number or as a set two bit fields. Since linker garbage collection is not happening when building x86 targets, a new configuration option is being added to include the new module only when needed. BUG=chrome-os-partner:30489 TEST=verified that nyan_big still reports proper revision ID. Change-Id: Ib55122c359629b58288c1022da83e6c63dc2264d Original-Change-Id: I243c9f43c82bd4a41de2154bbdbd07df0a241046 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/209673 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> (cherry picked from commit c79ef1c545d073eaad69e6c8c629f9656b8c2f3e) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Reviewed-on: http://review.coreboot.org/8717 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-07-23 18:40:02 +02:00
/*
* This file is part of the coreboot project.
*
* Copyright 2014 Google Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <delay.h>
gpio: Extend common GPIO header, simplify function names We've had gpiolib.h which defines a few common GPIO access functions for a while, but it wasn't really complete. This patch adds the missing gpio_output() function, and also renames the unwieldy gpio_get_in_value() and gpio_set_out_value() to the much easier to handle gpio_get() and gpio_set(). The header is renamed to the simpler gpio.h while we're at it (there was never really anything "lib" about it, and it was presumably just chosen due to the IPQ806x include/ conflict problem that is now resolved). It also moves the definition of gpio_t into SoC-specific code, so that different implementations are free to encode their platform-specific GPIO parameters in those 4 bytes in the most convenient way (such as the rk3288 with a bitfield struct). Every SoC intending to use this common API should supply a <soc/gpio.h> that typedefs gpio_t to a type at most 4 bytes in length. Files accessing the API only need to include <gpio.h> which may pull in additional things (like a gpio_t creation macro) from <soc/gpio.h> on its own. For now the API is still only used on non-x86 SoCs. Whether it makes sense to expand it to x86 as well should be separately evaluated at a later point (by someone who understands those systems better). Also, Exynos retains its old, incompatible GPIO API even though it would be a prime candidate, because it's currently just not worth the effort. BUG=None TEST=Compiled on Daisy, Peach_Pit, Nyan_Blaze, Rush_Ryu, Storm and Veyron_Pinky. Change-Id: Ieee77373c2bd13d07ece26fa7f8b08be324842fe Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 9e04902ada56b929e3829f2c3b4aeb618682096e Original-Change-Id: I6c1e7d1e154d9b02288aabedb397e21e1aadfa15 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/220975 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9400 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2014-09-25 00:40:49 +02:00
#include <gpio.h>
Generalize revision number calculation function Some platforms use tertiary interpretation of GPIO input state to increase number of distinct values represented by a limited number of GPIOs. The three states are - external pull down (interpreted as 0) - external pull up (1) - not connected (2) This has been required by Nvidia devices so far, but Exynos and Ipq8086 platforms need this too. This patch moves the function reading the tertiary state into the library and exposes the necessary GPIO API functions in a new include file. The functions are still supposed to be provided by platform specific modules. The function interpreting the GPIO states has been modified to allow to interpret the state either as a true tertiary number or as a set two bit fields. Since linker garbage collection is not happening when building x86 targets, a new configuration option is being added to include the new module only when needed. BUG=chrome-os-partner:30489 TEST=verified that nyan_big still reports proper revision ID. Change-Id: Ib55122c359629b58288c1022da83e6c63dc2264d Original-Change-Id: I243c9f43c82bd4a41de2154bbdbd07df0a241046 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/209673 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> (cherry picked from commit c79ef1c545d073eaad69e6c8c629f9656b8c2f3e) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Reviewed-on: http://review.coreboot.org/8717 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-07-23 18:40:02 +02:00
gpio: Extend common GPIO header, simplify function names We've had gpiolib.h which defines a few common GPIO access functions for a while, but it wasn't really complete. This patch adds the missing gpio_output() function, and also renames the unwieldy gpio_get_in_value() and gpio_set_out_value() to the much easier to handle gpio_get() and gpio_set(). The header is renamed to the simpler gpio.h while we're at it (there was never really anything "lib" about it, and it was presumably just chosen due to the IPQ806x include/ conflict problem that is now resolved). It also moves the definition of gpio_t into SoC-specific code, so that different implementations are free to encode their platform-specific GPIO parameters in those 4 bytes in the most convenient way (such as the rk3288 with a bitfield struct). Every SoC intending to use this common API should supply a <soc/gpio.h> that typedefs gpio_t to a type at most 4 bytes in length. Files accessing the API only need to include <gpio.h> which may pull in additional things (like a gpio_t creation macro) from <soc/gpio.h> on its own. For now the API is still only used on non-x86 SoCs. Whether it makes sense to expand it to x86 as well should be separately evaluated at a later point (by someone who understands those systems better). Also, Exynos retains its old, incompatible GPIO API even though it would be a prime candidate, because it's currently just not worth the effort. BUG=None TEST=Compiled on Daisy, Peach_Pit, Nyan_Blaze, Rush_Ryu, Storm and Veyron_Pinky. Change-Id: Ieee77373c2bd13d07ece26fa7f8b08be324842fe Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 9e04902ada56b929e3829f2c3b4aeb618682096e Original-Change-Id: I6c1e7d1e154d9b02288aabedb397e21e1aadfa15 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/220975 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9400 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2014-09-25 00:40:49 +02:00
int gpio_get_tristates(gpio_t gpio[], int num_gpio, int tertiary)
Generalize revision number calculation function Some platforms use tertiary interpretation of GPIO input state to increase number of distinct values represented by a limited number of GPIOs. The three states are - external pull down (interpreted as 0) - external pull up (1) - not connected (2) This has been required by Nvidia devices so far, but Exynos and Ipq8086 platforms need this too. This patch moves the function reading the tertiary state into the library and exposes the necessary GPIO API functions in a new include file. The functions are still supposed to be provided by platform specific modules. The function interpreting the GPIO states has been modified to allow to interpret the state either as a true tertiary number or as a set two bit fields. Since linker garbage collection is not happening when building x86 targets, a new configuration option is being added to include the new module only when needed. BUG=chrome-os-partner:30489 TEST=verified that nyan_big still reports proper revision ID. Change-Id: Ib55122c359629b58288c1022da83e6c63dc2264d Original-Change-Id: I243c9f43c82bd4a41de2154bbdbd07df0a241046 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/209673 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> (cherry picked from commit c79ef1c545d073eaad69e6c8c629f9656b8c2f3e) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Reviewed-on: http://review.coreboot.org/8717 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-07-23 18:40:02 +02:00
{
/*
* GPIOs which are tied to stronger external pull up or pull down
* will stay there regardless of the internal pull up or pull
* down setting.
*
* GPIOs which are floating will go to whatever level they're
* internally pulled to.
*/
int temp;
int index;
int id = 0;
char value[num_gpio];
/* Enable internal pull up */
for (index = 0; index < num_gpio; ++index)
gpio_input_pullup(gpio[index]);
/* Wait until signals become stable */
udelay(10);
/* Get gpio values at internal pull up */
for (index = 0; index < num_gpio; ++index)
gpio: Extend common GPIO header, simplify function names We've had gpiolib.h which defines a few common GPIO access functions for a while, but it wasn't really complete. This patch adds the missing gpio_output() function, and also renames the unwieldy gpio_get_in_value() and gpio_set_out_value() to the much easier to handle gpio_get() and gpio_set(). The header is renamed to the simpler gpio.h while we're at it (there was never really anything "lib" about it, and it was presumably just chosen due to the IPQ806x include/ conflict problem that is now resolved). It also moves the definition of gpio_t into SoC-specific code, so that different implementations are free to encode their platform-specific GPIO parameters in those 4 bytes in the most convenient way (such as the rk3288 with a bitfield struct). Every SoC intending to use this common API should supply a <soc/gpio.h> that typedefs gpio_t to a type at most 4 bytes in length. Files accessing the API only need to include <gpio.h> which may pull in additional things (like a gpio_t creation macro) from <soc/gpio.h> on its own. For now the API is still only used on non-x86 SoCs. Whether it makes sense to expand it to x86 as well should be separately evaluated at a later point (by someone who understands those systems better). Also, Exynos retains its old, incompatible GPIO API even though it would be a prime candidate, because it's currently just not worth the effort. BUG=None TEST=Compiled on Daisy, Peach_Pit, Nyan_Blaze, Rush_Ryu, Storm and Veyron_Pinky. Change-Id: Ieee77373c2bd13d07ece26fa7f8b08be324842fe Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 9e04902ada56b929e3829f2c3b4aeb618682096e Original-Change-Id: I6c1e7d1e154d9b02288aabedb397e21e1aadfa15 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/220975 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9400 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2014-09-25 00:40:49 +02:00
value[index] = gpio_get(gpio[index]);
Generalize revision number calculation function Some platforms use tertiary interpretation of GPIO input state to increase number of distinct values represented by a limited number of GPIOs. The three states are - external pull down (interpreted as 0) - external pull up (1) - not connected (2) This has been required by Nvidia devices so far, but Exynos and Ipq8086 platforms need this too. This patch moves the function reading the tertiary state into the library and exposes the necessary GPIO API functions in a new include file. The functions are still supposed to be provided by platform specific modules. The function interpreting the GPIO states has been modified to allow to interpret the state either as a true tertiary number or as a set two bit fields. Since linker garbage collection is not happening when building x86 targets, a new configuration option is being added to include the new module only when needed. BUG=chrome-os-partner:30489 TEST=verified that nyan_big still reports proper revision ID. Change-Id: Ib55122c359629b58288c1022da83e6c63dc2264d Original-Change-Id: I243c9f43c82bd4a41de2154bbdbd07df0a241046 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/209673 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> (cherry picked from commit c79ef1c545d073eaad69e6c8c629f9656b8c2f3e) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Reviewed-on: http://review.coreboot.org/8717 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-07-23 18:40:02 +02:00
/* Enable internal pull down */
for (index = 0; index < num_gpio; ++index)
gpio_input_pulldown(gpio[index]);
/* Wait until signals become stable */
udelay(10);
/*
* Get gpio values at internal pull down.
* Compare with gpio pull up value and then
* determine a gpio final value/state:
* 0: pull down
* 1: pull up
* 2: floating
*/
for (index = num_gpio - 1; index >= 0; --index) {
Generalize revision number calculation function Some platforms use tertiary interpretation of GPIO input state to increase number of distinct values represented by a limited number of GPIOs. The three states are - external pull down (interpreted as 0) - external pull up (1) - not connected (2) This has been required by Nvidia devices so far, but Exynos and Ipq8086 platforms need this too. This patch moves the function reading the tertiary state into the library and exposes the necessary GPIO API functions in a new include file. The functions are still supposed to be provided by platform specific modules. The function interpreting the GPIO states has been modified to allow to interpret the state either as a true tertiary number or as a set two bit fields. Since linker garbage collection is not happening when building x86 targets, a new configuration option is being added to include the new module only when needed. BUG=chrome-os-partner:30489 TEST=verified that nyan_big still reports proper revision ID. Change-Id: Ib55122c359629b58288c1022da83e6c63dc2264d Original-Change-Id: I243c9f43c82bd4a41de2154bbdbd07df0a241046 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/209673 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> (cherry picked from commit c79ef1c545d073eaad69e6c8c629f9656b8c2f3e) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Reviewed-on: http://review.coreboot.org/8717 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-07-23 18:40:02 +02:00
if (tertiary)
id *= 3;
else
id <<= 2;
gpio: Extend common GPIO header, simplify function names We've had gpiolib.h which defines a few common GPIO access functions for a while, but it wasn't really complete. This patch adds the missing gpio_output() function, and also renames the unwieldy gpio_get_in_value() and gpio_set_out_value() to the much easier to handle gpio_get() and gpio_set(). The header is renamed to the simpler gpio.h while we're at it (there was never really anything "lib" about it, and it was presumably just chosen due to the IPQ806x include/ conflict problem that is now resolved). It also moves the definition of gpio_t into SoC-specific code, so that different implementations are free to encode their platform-specific GPIO parameters in those 4 bytes in the most convenient way (such as the rk3288 with a bitfield struct). Every SoC intending to use this common API should supply a <soc/gpio.h> that typedefs gpio_t to a type at most 4 bytes in length. Files accessing the API only need to include <gpio.h> which may pull in additional things (like a gpio_t creation macro) from <soc/gpio.h> on its own. For now the API is still only used on non-x86 SoCs. Whether it makes sense to expand it to x86 as well should be separately evaluated at a later point (by someone who understands those systems better). Also, Exynos retains its old, incompatible GPIO API even though it would be a prime candidate, because it's currently just not worth the effort. BUG=None TEST=Compiled on Daisy, Peach_Pit, Nyan_Blaze, Rush_Ryu, Storm and Veyron_Pinky. Change-Id: Ieee77373c2bd13d07ece26fa7f8b08be324842fe Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 9e04902ada56b929e3829f2c3b4aeb618682096e Original-Change-Id: I6c1e7d1e154d9b02288aabedb397e21e1aadfa15 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/220975 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9400 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2014-09-25 00:40:49 +02:00
temp = gpio_get(gpio[index]);
Generalize revision number calculation function Some platforms use tertiary interpretation of GPIO input state to increase number of distinct values represented by a limited number of GPIOs. The three states are - external pull down (interpreted as 0) - external pull up (1) - not connected (2) This has been required by Nvidia devices so far, but Exynos and Ipq8086 platforms need this too. This patch moves the function reading the tertiary state into the library and exposes the necessary GPIO API functions in a new include file. The functions are still supposed to be provided by platform specific modules. The function interpreting the GPIO states has been modified to allow to interpret the state either as a true tertiary number or as a set two bit fields. Since linker garbage collection is not happening when building x86 targets, a new configuration option is being added to include the new module only when needed. BUG=chrome-os-partner:30489 TEST=verified that nyan_big still reports proper revision ID. Change-Id: Ib55122c359629b58288c1022da83e6c63dc2264d Original-Change-Id: I243c9f43c82bd4a41de2154bbdbd07df0a241046 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/209673 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> (cherry picked from commit c79ef1c545d073eaad69e6c8c629f9656b8c2f3e) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Reviewed-on: http://review.coreboot.org/8717 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-07-23 18:40:02 +02:00
id += ((value[index] ^ temp) << 1) | temp;
}
/* Disable pull up / pull down to conserve power */
for (index = 0; index < num_gpio; ++index)
gpio_input(gpio[index]);
return id;
}