1963a2afc8
Add the 'gpiomux' api, which addresses the following shortcomings of existing tlmm api: - gpio power-collapse, which is managed by a peripheral processor on other targets, must be managed by the application processor on the 8x60. - The enable/disable flag of the legacy gpio_tlmm_config api is not applicable on the 8x60, and causes confusion. - The gpio 'direction' bits are meaningless for all func_sel configurations except for generic-gpio mode (func_sel 0), in which case the gpio_direction_* functions should be used. Having these bits in the tlmm api leads to confusion and misuse of the gpiolib api, and they have been removed in gpiomux. - The functional api of the legacy system ran contrary to the typical use-case, which is a single massive configuration at boot. Rather than forcing hundreds of 'config' function calls, the new api allows data to be configured with a single table. gpiomux_get and gpiomux_put are meant to be called automatically when gpio_request and gpio_free are called, giving automatic gpiomux/tlmm control to those drivers/lines with simple power profiles - in the simplest cases, an entry in the gpiomux table and the correct usage of gpiolib is all that is required to get proper gpio power control. Signed-off-by: Gregory Bean <gbean@codeaurora.org> Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
95 lines
3.2 KiB
C
95 lines
3.2 KiB
C
/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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#ifndef __ARCH_ARM_MACH_MSM_GPIOMUX_H
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#define __ARCH_ARM_MACH_MSM_GPIOMUX_H
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#include <linux/bitops.h>
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#if defined(CONFIG_MSM_V2_TLMM)
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#include "gpiomux-v2.h"
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#else
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#include "gpiomux-v1.h"
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#endif
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/**
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* struct msm_gpiomux_config: gpiomux settings for one gpio line.
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*
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* A complete gpiomux config is the bitwise-or of a drive-strength,
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* function, and pull. For functions other than GPIO, the OE
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* is hard-wired according to the function. For GPIO mode,
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* OE is controlled by gpiolib.
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*
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* Available settings differ by target; see the gpiomux header
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* specific to your target arch for available configurations.
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*
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* @active: The configuration to be installed when the line is
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* active, or its reference count is > 0.
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* @suspended: The configuration to be installed when the line
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* is suspended, or its reference count is 0.
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* @ref: The reference count of the line. For internal use of
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* the gpiomux framework only.
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*/
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struct msm_gpiomux_config {
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gpiomux_config_t active;
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gpiomux_config_t suspended;
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unsigned ref;
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};
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/**
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* @GPIOMUX_VALID: If set, the config field contains 'good data'.
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* The absence of this bit will prevent the gpiomux
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* system from applying the configuration under all
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* circumstances.
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*/
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enum {
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GPIOMUX_VALID = BIT(sizeof(gpiomux_config_t) * BITS_PER_BYTE - 1),
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GPIOMUX_CTL_MASK = GPIOMUX_VALID,
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};
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/* Each architecture must provide its own instance of this table.
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* To avoid having gpiomux manage any given gpio, one or both of
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* the entries can avoid setting GPIOMUX_VALID - the absence
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* of that flag will prevent the configuration from being applied
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* during state transitions.
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*/
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extern struct msm_gpiomux_config msm_gpiomux_configs[GPIOMUX_NGPIOS];
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/* Increment a gpio's reference count, possibly activating the line. */
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int __must_check msm_gpiomux_get(unsigned gpio);
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/* Decrement a gpio's reference count, possibly suspending the line. */
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int msm_gpiomux_put(unsigned gpio);
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/* Install a new configuration to the gpio line. To avoid overwriting
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* a configuration, leave the VALID bit out.
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*/
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int msm_gpiomux_write(unsigned gpio,
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gpiomux_config_t active,
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gpiomux_config_t suspended);
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/* Architecture-internal function for use by the framework only.
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* This function can assume the following:
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* - the gpio value has passed a bounds-check
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* - the gpiomux spinlock has been obtained
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*
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* This function is not for public consumption. External users
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* should use msm_gpiomux_write.
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*/
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void __msm_gpiomux_write(unsigned gpio, gpiomux_config_t val);
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#endif
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