lpc32xx: add GPIO support

This driver only supports Driver Model, not legacy model.

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
This commit is contained in:
Albert ARIBAUD \(3ADEV\) 2015-03-31 11:40:46 +02:00 committed by Albert ARIBAUD
parent 5e862b9539
commit 606f704760
5 changed files with 349 additions and 0 deletions

View file

@ -9,6 +9,7 @@
#include <asm/arch/clk.h>
#include <asm/arch/uart.h>
#include <asm/io.h>
#include <dm.h>
static struct clk_pm_regs *clk = (struct clk_pm_regs *)CLK_PM_BASE;
static struct uart_ctrl_regs *ctrl = (struct uart_ctrl_regs *)UART_CTRL_BASE;
@ -61,3 +62,7 @@ void lpc32xx_i2c_init(unsigned int devnum)
ctrl |= CLK_I2C2_ENABLE;
writel(ctrl, &clk->i2cclk_ctrl);
}
U_BOOT_DEVICE(lpc32xx_gpios) = {
.name = "gpio_lpc32xx"
};

View file

@ -0,0 +1,43 @@
/*
* LPC32xx GPIO interface
*
* (C) Copyright 2014 DENX Software Engineering GmbH
* Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr>
*
* SPDX-License-Identifier: GPL-2.0+
*/
/**
* GPIO Register map for LPC32xx
*/
struct gpio_regs {
u32 p3_inp_state;
u32 p3_outp_set;
u32 p3_outp_clr;
u32 p3_outp_state;
/* Watch out! the following are shared between p2 and p3 */
u32 p2_p3_dir_set;
u32 p2_p3_dir_clr;
u32 p2_p3_dir_state;
/* Now back to 'one register for one port' */
u32 p2_inp_state;
u32 p2_outp_set;
u32 p2_outp_clr;
u32 reserved1[6];
u32 p0_inp_state;
u32 p0_outp_set;
u32 p0_outp_clr;
u32 p0_outp_state;
u32 p0_dir_set;
u32 p0_dir_clr;
u32 p0_dir_state;
u32 reserved2;
u32 p1_inp_state;
u32 p1_outp_set;
u32 p1_outp_clr;
u32 p1_outp_state;
u32 p1_dir_set;
u32 p1_dir_clr;
u32 p1_dir_state;
};

View file

@ -7,3 +7,10 @@ config DM_GPIO
the GPIO uclass. Drivers provide methods to query the
particular GPIOs that they provide. The uclass interface
is defined in include/asm-generic/gpio.h.
config LPC32XX_GPIO
bool "LPC32XX GPIO driver"
depends on DM
default n
help
Support for the LPC32XX GPIO driver.

View file

@ -41,3 +41,4 @@ obj-$(CONFIG_ADI_GPIO2) += adi_gpio2.o
obj-$(CONFIG_TCA642X) += tca642x.o
oby-$(CONFIG_SX151X) += sx151x.o
obj-$(CONFIG_SUNXI_GPIO) += sunxi_gpio.o
obj-$(CONFIG_LPC32XX_GPIO) += lpc32xx_gpio.o

293
drivers/gpio/lpc32xx_gpio.c Normal file
View file

@ -0,0 +1,293 @@
/*
* LPC32xxGPIO driver
*
* (C) Copyright 2014 DENX Software Engineering GmbH
* Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm/io.h>
#include <asm/arch-lpc32xx/cpu.h>
#include <asm/arch-lpc32xx/gpio.h>
#include <asm-generic/gpio.h>
#include <dm.h>
/**
* LPC32xx GPIOs work in banks but are non-homogeneous:
* - each bank holds a different number of GPIOs
* - some GPIOs are input/ouput, some input only, some output only;
* - some GPIOs have different meanings as an input and as an output;
* - some GPIOs are controlled on a given port and bit index, but
* read on another one.
*
* In order to keep this code simple, GPIOS are considered here as
* homogeneous and linear, from 0 to 127.
*
* ** WARNING #1 **
*
* Client code is responsible for properly using valid GPIO numbers,
* including cases where a single physical GPIO has differing numbers
* for setting its direction, reading it and/or writing to it.
*
* ** WARNING #2 **
*
* Please read NOTE in description of lpc32xx_gpio_get_function().
*/
#define LPC32XX_GPIOS 128
struct lpc32xx_gpio_platdata {
struct gpio_regs *regs;
/* GPIO FUNCTION: SEE WARNING #2 */
signed char function[LPC32XX_GPIOS];
};
/**
* We have 4 GPIO ports of 32 bits each
*/
#define MAX_GPIO 128
#define GPIO_TO_PORT(gpio) ((gpio / 32) & 3)
#define GPIO_TO_RANK(gpio) (gpio % 32)
#define GPIO_TO_MASK(gpio) (1 << (gpio % 32))
/**
* Configure a GPIO number 'offset' as input
*/
static int lpc32xx_gpio_direction_input(struct udevice *dev, unsigned offset)
{
int port, mask;
struct lpc32xx_gpio_platdata *gpio_platdata = dev_get_platdata(dev);
struct gpio_regs *regs = gpio_platdata->regs;
port = GPIO_TO_PORT(offset);
mask = GPIO_TO_MASK(offset);
switch (port) {
case 0:
writel(mask, &regs->p0_dir_clr);
break;
case 1:
writel(mask, &regs->p1_dir_clr);
break;
case 2:
/* ports 2 and 3 share a common direction */
case 3:
writel(mask, &regs->p2_p3_dir_clr);
break;
default:
return -1;
}
/* GPIO FUNCTION: SEE WARNING #2 */
gpio_platdata->function[offset] = GPIOF_INPUT;
return 0;
}
/**
* Get the value of a GPIO
*/
static int lpc32xx_gpio_get_value(struct udevice *dev, unsigned offset)
{
int port, rank, mask, value;
struct lpc32xx_gpio_platdata *gpio_platdata = dev_get_platdata(dev);
struct gpio_regs *regs = gpio_platdata->regs;
port = GPIO_TO_PORT(offset);
switch (port) {
case 0:
value = readl(&regs->p0_inp_state);
break;
case 1:
value = readl(&regs->p1_inp_state);
break;
case 2:
value = readl(&regs->p2_inp_state);
break;
case 3:
value = readl(&regs->p3_inp_state);
break;
default:
return -1;
}
rank = GPIO_TO_RANK(offset);
mask = GPIO_TO_MASK(offset);
return (value & mask) >> rank;
}
/**
* Set a GPIO
*/
static int gpio_set(struct udevice *dev, unsigned gpio)
{
int port, mask;
struct lpc32xx_gpio_platdata *gpio_platdata = dev_get_platdata(dev);
struct gpio_regs *regs = gpio_platdata->regs;
port = GPIO_TO_PORT(gpio);
mask = GPIO_TO_MASK(gpio);
switch (port) {
case 0:
writel(mask, &regs->p0_outp_set);
break;
case 1:
writel(mask, &regs->p1_outp_set);
break;
case 2:
writel(mask, &regs->p2_outp_set);
break;
case 3:
writel(mask, &regs->p3_outp_set);
break;
default:
return -1;
}
return 0;
}
/**
* Clear a GPIO
*/
static int gpio_clr(struct udevice *dev, unsigned gpio)
{
int port, mask;
struct lpc32xx_gpio_platdata *gpio_platdata = dev_get_platdata(dev);
struct gpio_regs *regs = gpio_platdata->regs;
port = GPIO_TO_PORT(gpio);
mask = GPIO_TO_MASK(gpio);
switch (port) {
case 0:
writel(mask, &regs->p0_outp_clr);
break;
case 1:
writel(mask, &regs->p1_outp_clr);
break;
case 2:
writel(mask, &regs->p2_outp_clr);
break;
case 3:
writel(mask, &regs->p3_outp_clr);
break;
default:
return -1;
}
return 0;
}
/**
* Set the value of a GPIO
*/
static int lpc32xx_gpio_set_value(struct udevice *dev, unsigned offset,
int value)
{
if (value)
return gpio_set(dev, offset);
else
return gpio_clr(dev, offset);
}
/**
* Configure a GPIO number 'offset' as output with given initial value.
*/
static int lpc32xx_gpio_direction_output(struct udevice *dev, unsigned offset,
int value)
{
int port, mask;
struct lpc32xx_gpio_platdata *gpio_platdata = dev_get_platdata(dev);
struct gpio_regs *regs = gpio_platdata->regs;
port = GPIO_TO_PORT(offset);
mask = GPIO_TO_MASK(offset);
switch (port) {
case 0:
writel(mask, &regs->p0_dir_set);
break;
case 1:
writel(mask, &regs->p1_dir_set);
break;
case 2:
/* ports 2 and 3 share a common direction */
case 3:
writel(mask, &regs->p2_p3_dir_set);
break;
default:
return -1;
}
/* GPIO FUNCTION: SEE WARNING #2 */
gpio_platdata->function[offset] = GPIOF_OUTPUT;
return lpc32xx_gpio_set_value(dev, offset, value);
}
/**
* GPIO functions are supposed to be computed from their current
* configuration, but that's way too complicated in LPC32XX. A simpler
* approach is used, where the GPIO functions are cached in an array.
* When the GPIO is in use, its function is either "input" or "output"
* depending on its direction, otherwise its function is "unknown".
*
* ** NOTE **
*
* THIS APPROACH WAS CHOSEN DU TO THE COMPLEX NATURE OF THE LPC32XX
* GPIOS; DO NOT TAKE THIS AS AN EXAMPLE FOR NEW CODE.
*/
static int lpc32xx_gpio_get_function(struct udevice *dev, unsigned offset)
{
struct lpc32xx_gpio_platdata *gpio_platdata = dev_get_platdata(dev);
return gpio_platdata->function[offset];
}
static const struct dm_gpio_ops gpio_lpc32xx_ops = {
.direction_input = lpc32xx_gpio_direction_input,
.direction_output = lpc32xx_gpio_direction_output,
.get_value = lpc32xx_gpio_get_value,
.set_value = lpc32xx_gpio_set_value,
.get_function = lpc32xx_gpio_get_function,
};
static int lpc32xx_gpio_probe(struct udevice *dev)
{
struct lpc32xx_gpio_platdata *gpio_platdata = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
if (dev->of_offset == -1) {
/* Tell the uclass how many GPIOs we have */
uc_priv->gpio_count = LPC32XX_GPIOS;
}
/* set base address for GPIO registers */
gpio_platdata->regs = (struct gpio_regs *)GPIO_BASE;
/* all GPIO functions are unknown until requested */
/* GPIO FUNCTION: SEE WARNING #2 */
memset(gpio_platdata->function, GPIOF_UNKNOWN,
sizeof(gpio_platdata->function));
return 0;
}
U_BOOT_DRIVER(gpio_lpc32xx) = {
.name = "gpio_lpc32xx",
.id = UCLASS_GPIO,
.ops = &gpio_lpc32xx_ops,
.probe = lpc32xx_gpio_probe,
.priv_auto_alloc_size = sizeof(struct lpc32xx_gpio_platdata),
};