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authorAlbert ARIBAUD \(3ADEV\) <albert.aribaud@3adev.fr>2015-03-31 11:40:46 +0200
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2015-04-10 14:23:09 +0200
commit606f7047603422746d112e41937649d44f311af4 (patch)
treece2cabc328db2721e3ae3204f16e2cb637b4ba79 /drivers/gpio
parent5e862b95399e6e5ea7748ee29a38756685d622fd (diff)
lpc32xx: add GPIO support
This driver only supports Driver Model, not legacy model. Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/Kconfig7
-rw-r--r--drivers/gpio/Makefile1
-rw-r--r--drivers/gpio/lpc32xx_gpio.c293
3 files changed, 301 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b609e73bba..7b5178a23a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -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.
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index fe9a3b2396..85f71c5d4a 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -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
diff --git a/drivers/gpio/lpc32xx_gpio.c b/drivers/gpio/lpc32xx_gpio.c
new file mode 100644
index 0000000000..96b312592b
--- /dev/null
+++ b/drivers/gpio/lpc32xx_gpio.c
@@ -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),
+};