From 1963a2afc81afe6d85e7a12538b74a9919d958ae Mon Sep 17 00:00:00 2001 From: Gregory Bean Date: Sat, 28 Aug 2010 10:05:44 -0700 Subject: msm: add gpiomux api for gpio multiplex & configuration. 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 Signed-off-by: Daniel Walker --- arch/arm/mach-msm/gpiomux.c | 96 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 arch/arm/mach-msm/gpiomux.c (limited to 'arch/arm/mach-msm/gpiomux.c') diff --git a/arch/arm/mach-msm/gpiomux.c b/arch/arm/mach-msm/gpiomux.c new file mode 100644 index 000000000000..53af21abd155 --- /dev/null +++ b/arch/arm/mach-msm/gpiomux.c @@ -0,0 +1,96 @@ +/* Copyright (c) 2010, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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 Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ +#include +#include +#include "gpiomux.h" + +static DEFINE_SPINLOCK(gpiomux_lock); + +int msm_gpiomux_write(unsigned gpio, + gpiomux_config_t active, + gpiomux_config_t suspended) +{ + struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio; + unsigned long irq_flags; + gpiomux_config_t setting; + + if (gpio >= GPIOMUX_NGPIOS) + return -EINVAL; + + spin_lock_irqsave(&gpiomux_lock, irq_flags); + + if (active & GPIOMUX_VALID) + cfg->active = active; + + if (suspended & GPIOMUX_VALID) + cfg->suspended = suspended; + + setting = cfg->ref ? active : suspended; + if (setting & GPIOMUX_VALID) + __msm_gpiomux_write(gpio, setting); + + spin_unlock_irqrestore(&gpiomux_lock, irq_flags); + return 0; +} +EXPORT_SYMBOL(msm_gpiomux_write); + +int msm_gpiomux_get(unsigned gpio) +{ + struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio; + unsigned long irq_flags; + + if (gpio >= GPIOMUX_NGPIOS) + return -EINVAL; + + spin_lock_irqsave(&gpiomux_lock, irq_flags); + if (cfg->ref++ == 0 && cfg->active & GPIOMUX_VALID) + __msm_gpiomux_write(gpio, cfg->active); + spin_unlock_irqrestore(&gpiomux_lock, irq_flags); + return 0; +} +EXPORT_SYMBOL(msm_gpiomux_get); + +int msm_gpiomux_put(unsigned gpio) +{ + struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio; + unsigned long irq_flags; + + if (gpio >= GPIOMUX_NGPIOS) + return -EINVAL; + + spin_lock_irqsave(&gpiomux_lock, irq_flags); + BUG_ON(cfg->ref == 0); + if (--cfg->ref == 0 && cfg->suspended & GPIOMUX_VALID) + __msm_gpiomux_write(gpio, cfg->suspended); + spin_unlock_irqrestore(&gpiomux_lock, irq_flags); + return 0; +} +EXPORT_SYMBOL(msm_gpiomux_put); + +static int __init gpiomux_init(void) +{ + unsigned n; + + for (n = 0; n < GPIOMUX_NGPIOS; ++n) { + msm_gpiomux_configs[n].ref = 0; + if (!(msm_gpiomux_configs[n].suspended & GPIOMUX_VALID)) + continue; + __msm_gpiomux_write(n, msm_gpiomux_configs[n].suspended); + } + return 0; +} +postcore_initcall(gpiomux_init); -- cgit v1.2.3-59-g8ed1b