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https://github.com/brain-hackers/u-boot-brain
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![Tom Rini](/assets/img/avatar_default.png)
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
322 lines
7.1 KiB
C
322 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* LPC32xxGPIO driver
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*
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* (C) Copyright 2014 DENX Software Engineering GmbH
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* Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr>
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*/
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#include <common.h>
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#include <asm/io.h>
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#include <asm/arch-lpc32xx/cpu.h>
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#include <asm/arch-lpc32xx/gpio.h>
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#include <asm-generic/gpio.h>
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#include <dm.h>
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/**
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* LPC32xx GPIOs work in banks but are non-homogeneous:
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* - each bank holds a different number of GPIOs
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* - some GPIOs are input/ouput, some input only, some output only;
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* - some GPIOs have different meanings as an input and as an output;
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* - some GPIOs are controlled on a given port and bit index, but
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* read on another one.
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*
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* In order to keep this code simple, GPIOS are considered here as
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* homogeneous and linear, from 0 to 159.
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*
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* ** WARNING #1 **
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*
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* Client code is responsible for properly using valid GPIO numbers,
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* including cases where a single physical GPIO has differing numbers
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* for setting its direction, reading it and/or writing to it.
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*
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* ** WARNING #2 **
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*
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* Please read NOTE in description of lpc32xx_gpio_get_function().
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*/
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#define LPC32XX_GPIOS 160
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struct lpc32xx_gpio_priv {
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struct gpio_regs *regs;
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/* GPIO FUNCTION: SEE WARNING #2 */
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signed char function[LPC32XX_GPIOS];
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};
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/**
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* We have 4 GPIO ports of 32 bits each
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*
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* Port mapping offset (32 bits each):
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* - Port 0: 0
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* - Port 1: 32
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* - Port 2: 64
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* - Port 3: GPO / GPIO (output): 96
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* - Port 3: GPI: 128
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*/
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#define MAX_GPIO 160
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#define GPIO_TO_PORT(gpio) ((gpio / 32) & 7)
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#define GPIO_TO_RANK(gpio) (gpio % 32)
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#define GPIO_TO_MASK(gpio) (1 << (gpio % 32))
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/**
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* Configure a GPIO number 'offset' as input
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*/
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static int lpc32xx_gpio_direction_input(struct udevice *dev, unsigned offset)
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{
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int port, mask;
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struct lpc32xx_gpio_priv *gpio_priv = dev_get_priv(dev);
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struct gpio_regs *regs = gpio_priv->regs;
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port = GPIO_TO_PORT(offset);
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mask = GPIO_TO_MASK(offset);
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switch (port) {
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case 0:
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writel(mask, ®s->p0_dir_clr);
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break;
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case 1:
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writel(mask, ®s->p1_dir_clr);
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break;
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case 2:
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/* ports 2 and 3 share a common direction */
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writel(mask, ®s->p2_p3_dir_clr);
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break;
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case 3:
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/* Setup direction only for GPIO_xx. */
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if ((mask >= 25) && (mask <= 30))
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writel(mask, ®s->p2_p3_dir_clr);
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break;
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case 4:
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/* GPI_xx; nothing to do. */
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break;
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default:
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return -1;
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}
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/* GPIO FUNCTION: SEE WARNING #2 */
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gpio_priv->function[offset] = GPIOF_INPUT;
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return 0;
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}
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/**
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* Get the value of a GPIO
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*/
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static int lpc32xx_gpio_get_value(struct udevice *dev, unsigned offset)
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{
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int port, rank, mask, value;
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struct lpc32xx_gpio_priv *gpio_priv = dev_get_priv(dev);
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struct gpio_regs *regs = gpio_priv->regs;
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port = GPIO_TO_PORT(offset);
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switch (port) {
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case 0:
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value = readl(®s->p0_inp_state);
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break;
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case 1:
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value = readl(®s->p1_inp_state);
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break;
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case 2:
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value = readl(®s->p2_inp_state);
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break;
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case 3:
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/* Read GPO_xx and GPIO_xx (as output) using p3_outp_state. */
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value = readl(®s->p3_outp_state);
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break;
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case 4:
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/* Read GPI_xx and GPIO_xx (as input) using p3_inp_state. */
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value = readl(®s->p3_inp_state);
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break;
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default:
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return -1;
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}
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rank = GPIO_TO_RANK(offset);
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mask = GPIO_TO_MASK(offset);
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return (value & mask) >> rank;
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}
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/**
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* Set a GPIO
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*/
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static int gpio_set(struct udevice *dev, unsigned gpio)
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{
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int port, mask;
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struct lpc32xx_gpio_priv *gpio_priv = dev_get_priv(dev);
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struct gpio_regs *regs = gpio_priv->regs;
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port = GPIO_TO_PORT(gpio);
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mask = GPIO_TO_MASK(gpio);
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switch (port) {
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case 0:
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writel(mask, ®s->p0_outp_set);
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break;
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case 1:
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writel(mask, ®s->p1_outp_set);
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break;
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case 2:
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writel(mask, ®s->p2_outp_set);
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break;
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case 3:
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writel(mask, ®s->p3_outp_set);
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break;
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case 4:
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/* GPI_xx; invalid. */
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default:
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return -1;
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}
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return 0;
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}
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/**
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* Clear a GPIO
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*/
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static int gpio_clr(struct udevice *dev, unsigned gpio)
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{
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int port, mask;
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struct lpc32xx_gpio_priv *gpio_priv = dev_get_priv(dev);
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struct gpio_regs *regs = gpio_priv->regs;
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port = GPIO_TO_PORT(gpio);
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mask = GPIO_TO_MASK(gpio);
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switch (port) {
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case 0:
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writel(mask, ®s->p0_outp_clr);
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break;
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case 1:
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writel(mask, ®s->p1_outp_clr);
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break;
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case 2:
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writel(mask, ®s->p2_outp_clr);
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break;
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case 3:
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writel(mask, ®s->p3_outp_clr);
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break;
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case 4:
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/* GPI_xx; invalid. */
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default:
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return -1;
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}
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return 0;
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}
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/**
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* Set the value of a GPIO
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*/
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static int lpc32xx_gpio_set_value(struct udevice *dev, unsigned offset,
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int value)
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{
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if (value)
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return gpio_set(dev, offset);
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else
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return gpio_clr(dev, offset);
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}
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/**
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* Configure a GPIO number 'offset' as output with given initial value.
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*/
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static int lpc32xx_gpio_direction_output(struct udevice *dev, unsigned offset,
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int value)
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{
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int port, mask;
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struct lpc32xx_gpio_priv *gpio_priv = dev_get_priv(dev);
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struct gpio_regs *regs = gpio_priv->regs;
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port = GPIO_TO_PORT(offset);
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mask = GPIO_TO_MASK(offset);
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switch (port) {
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case 0:
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writel(mask, ®s->p0_dir_set);
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break;
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case 1:
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writel(mask, ®s->p1_dir_set);
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break;
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case 2:
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/* ports 2 and 3 share a common direction */
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writel(mask, ®s->p2_p3_dir_set);
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break;
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case 3:
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/* Setup direction only for GPIO_xx. */
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if ((mask >= 25) && (mask <= 30))
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writel(mask, ®s->p2_p3_dir_set);
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break;
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case 4:
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/* GPI_xx; invalid. */
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default:
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return -1;
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}
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/* GPIO FUNCTION: SEE WARNING #2 */
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gpio_priv->function[offset] = GPIOF_OUTPUT;
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return lpc32xx_gpio_set_value(dev, offset, value);
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}
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/**
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* GPIO functions are supposed to be computed from their current
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* configuration, but that's way too complicated in LPC32XX. A simpler
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* approach is used, where the GPIO functions are cached in an array.
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* When the GPIO is in use, its function is either "input" or "output"
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* depending on its direction, otherwise its function is "unknown".
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*
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* ** NOTE **
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*
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* THIS APPROACH WAS CHOSEN DU TO THE COMPLEX NATURE OF THE LPC32XX
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* GPIOS; DO NOT TAKE THIS AS AN EXAMPLE FOR NEW CODE.
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*/
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static int lpc32xx_gpio_get_function(struct udevice *dev, unsigned offset)
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{
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struct lpc32xx_gpio_priv *gpio_priv = dev_get_priv(dev);
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return gpio_priv->function[offset];
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}
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static const struct dm_gpio_ops gpio_lpc32xx_ops = {
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.direction_input = lpc32xx_gpio_direction_input,
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.direction_output = lpc32xx_gpio_direction_output,
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.get_value = lpc32xx_gpio_get_value,
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.set_value = lpc32xx_gpio_set_value,
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.get_function = lpc32xx_gpio_get_function,
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};
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static int lpc32xx_gpio_probe(struct udevice *dev)
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{
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struct lpc32xx_gpio_priv *gpio_priv = dev_get_priv(dev);
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struct gpio_dev_priv *uc_priv = dev->uclass_priv;
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if (dev_of_offset(dev) == -1) {
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/* Tell the uclass how many GPIOs we have */
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uc_priv->gpio_count = LPC32XX_GPIOS;
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}
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/* set base address for GPIO registers */
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gpio_priv->regs = (struct gpio_regs *)GPIO_BASE;
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/* all GPIO functions are unknown until requested */
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/* GPIO FUNCTION: SEE WARNING #2 */
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memset(gpio_priv->function, GPIOF_UNKNOWN, sizeof(gpio_priv->function));
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return 0;
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}
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U_BOOT_DRIVER(gpio_lpc32xx) = {
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.name = "gpio_lpc32xx",
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.id = UCLASS_GPIO,
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.ops = &gpio_lpc32xx_ops,
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.probe = lpc32xx_gpio_probe,
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.priv_auto_alloc_size = sizeof(struct lpc32xx_gpio_priv),
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};
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