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![Anton Vorontsov](/assets/img/avatar_default.png)
Implement generic OF gpio hooks and thus make device-enabled GPIO chips (i.e. the ones that have gpio_chip->dev specified) automatically attach to the OpenFirmware subsystem. Which means that now we can handle I2C and SPI GPIO chips almost* transparently. * "Almost" because some chips still require platform data, and for these chips OF-glue is still needed, though with this change the glue will be much smaller. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Bill Gatliff <bgat@billgatliff.com> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Andrew Morton <akpm@linux-foundation.org> CC: linux-kernel@vger.kernel.org CC: devicetree-discuss@lists.ozlabs.org
215 lines
5.2 KiB
C
215 lines
5.2 KiB
C
/*
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* PPC4xx gpio driver
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*
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* Copyright (c) 2008 Harris Corporation
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* Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
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* Copyright (c) MontaVista Software, Inc. 2008.
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*
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* Author: Steve Falco <sfalco@harris.com>
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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
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* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_gpio.h>
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#include <linux/gpio.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#define GPIO_MASK(gpio) (0x80000000 >> (gpio))
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#define GPIO_MASK2(gpio) (0xc0000000 >> ((gpio) * 2))
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/* Physical GPIO register layout */
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struct ppc4xx_gpio {
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__be32 or;
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__be32 tcr;
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__be32 osrl;
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__be32 osrh;
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__be32 tsrl;
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__be32 tsrh;
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__be32 odr;
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__be32 ir;
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__be32 rr1;
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__be32 rr2;
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__be32 rr3;
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__be32 reserved1;
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__be32 isr1l;
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__be32 isr1h;
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__be32 isr2l;
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__be32 isr2h;
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__be32 isr3l;
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__be32 isr3h;
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};
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struct ppc4xx_gpio_chip {
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struct of_mm_gpio_chip mm_gc;
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spinlock_t lock;
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};
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/*
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* GPIO LIB API implementation for GPIOs
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*
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* There are a maximum of 32 gpios in each gpio controller.
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*/
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static inline struct ppc4xx_gpio_chip *
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to_ppc4xx_gpiochip(struct of_mm_gpio_chip *mm_gc)
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{
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return container_of(mm_gc, struct ppc4xx_gpio_chip, mm_gc);
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}
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static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
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{
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struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
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struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
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return in_be32(®s->ir) & GPIO_MASK(gpio);
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}
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static inline void
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__ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
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{
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struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
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struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
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if (val)
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setbits32(®s->or, GPIO_MASK(gpio));
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else
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clrbits32(®s->or, GPIO_MASK(gpio));
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}
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static void
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ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
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{
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struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
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struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);
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unsigned long flags;
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spin_lock_irqsave(&chip->lock, flags);
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__ppc4xx_gpio_set(gc, gpio, val);
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spin_unlock_irqrestore(&chip->lock, flags);
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pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
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}
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static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
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{
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struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
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struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);
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struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
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unsigned long flags;
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spin_lock_irqsave(&chip->lock, flags);
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/* Disable open-drain function */
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clrbits32(®s->odr, GPIO_MASK(gpio));
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/* Float the pin */
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clrbits32(®s->tcr, GPIO_MASK(gpio));
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/* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */
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if (gpio < 16) {
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clrbits32(®s->osrl, GPIO_MASK2(gpio));
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clrbits32(®s->tsrl, GPIO_MASK2(gpio));
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} else {
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clrbits32(®s->osrh, GPIO_MASK2(gpio));
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clrbits32(®s->tsrh, GPIO_MASK2(gpio));
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}
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spin_unlock_irqrestore(&chip->lock, flags);
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return 0;
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}
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static int
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ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
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{
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struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
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struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);
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struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
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unsigned long flags;
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spin_lock_irqsave(&chip->lock, flags);
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/* First set initial value */
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__ppc4xx_gpio_set(gc, gpio, val);
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/* Disable open-drain function */
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clrbits32(®s->odr, GPIO_MASK(gpio));
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/* Drive the pin */
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setbits32(®s->tcr, GPIO_MASK(gpio));
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/* Bits 0-15 use TSRL, bits 16-31 use TSRH */
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if (gpio < 16) {
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clrbits32(®s->osrl, GPIO_MASK2(gpio));
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clrbits32(®s->tsrl, GPIO_MASK2(gpio));
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} else {
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clrbits32(®s->osrh, GPIO_MASK2(gpio));
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clrbits32(®s->tsrh, GPIO_MASK2(gpio));
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}
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spin_unlock_irqrestore(&chip->lock, flags);
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pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
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return 0;
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}
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static int __init ppc4xx_add_gpiochips(void)
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{
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struct device_node *np;
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for_each_compatible_node(np, NULL, "ibm,ppc4xx-gpio") {
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int ret;
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struct ppc4xx_gpio_chip *ppc4xx_gc;
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struct of_mm_gpio_chip *mm_gc;
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struct gpio_chip *gc;
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ppc4xx_gc = kzalloc(sizeof(*ppc4xx_gc), GFP_KERNEL);
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if (!ppc4xx_gc) {
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ret = -ENOMEM;
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goto err;
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}
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spin_lock_init(&ppc4xx_gc->lock);
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mm_gc = &ppc4xx_gc->mm_gc;
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gc = &mm_gc->gc;
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gc->ngpio = 32;
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gc->direction_input = ppc4xx_gpio_dir_in;
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gc->direction_output = ppc4xx_gpio_dir_out;
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gc->get = ppc4xx_gpio_get;
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gc->set = ppc4xx_gpio_set;
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ret = of_mm_gpiochip_add(np, mm_gc);
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if (ret)
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goto err;
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continue;
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err:
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pr_err("%s: registration failed with status %d\n",
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np->full_name, ret);
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kfree(ppc4xx_gc);
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/* try others anyway */
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}
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return 0;
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}
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arch_initcall(ppc4xx_add_gpiochips);
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