[U-Boot] [PATCH v2 4/8] lpc32xx: add GPIO support

Albert ARIBAUD (3ADEV) albert.aribaud at 3adev.fr
Thu Feb 12 18:37:03 CET 2015


This driver only supports Driver Model, not legacy model.

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud at 3adev.fr>
---

Changes in v2:
- move from legacy to Driver Model support

 arch/arm/cpu/arm926ejs/lpc32xx/devices.c |   5 +
 arch/arm/include/asm/arch-lpc32xx/gpio.h |  43 +++++
 drivers/gpio/Makefile                    |   1 +
 drivers/gpio/lpc32xx_gpio.c              | 268 +++++++++++++++++++++++++++++++
 4 files changed, 317 insertions(+)
 create mode 100644 arch/arm/include/asm/arch-lpc32xx/gpio.h
 create mode 100644 drivers/gpio/lpc32xx_gpio.c

diff --git a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
index 81b53ea..a407098 100644
--- a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
+++ b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
@@ -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"
+};
diff --git a/arch/arm/include/asm/arch-lpc32xx/gpio.h b/arch/arm/include/asm/arch-lpc32xx/gpio.h
new file mode 100644
index 0000000..3bd94e3
--- /dev/null
+++ b/arch/arm/include/asm/arch-lpc32xx/gpio.h
@@ -0,0 +1,43 @@
+/*
+ * LPC32xx GPIO interface
+ *
+ * (C) Copyright 2014  DENX Software Engineering GmbH
+ * Written-by: Albert ARIBAUD <albert.aribaud at 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;
+};
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index aa11f15..559894a 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -37,3 +37,4 @@ 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 0000000..861975e
--- /dev/null
+++ b/drivers/gpio/lpc32xx_gpio.c
@@ -0,0 +1,268 @@
+/*
+ * LPC32xxGPIO driver
+ *
+ * (C) Copyright 2014  DENX Software Engineering GmbH
+ * Written-by: Albert ARIBAUD <albert.aribaud at 3adev.fr>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/**
+ * We only support driver model
+ */
+#ifndef CONFIG_DM_GPIO
+#error Please enable Driver Model GPIO in your target configuration.
+#endif
+
+#include <asm/io.h>
+#include <asm/arch-lpc32xx/cpu.h>
+#include <asm/arch-lpc32xx/gpio.h>
+#include <asm-generic/gpio.h>
+#include <dm.h>
+#include <malloc.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 **
+ *
+ * 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.
+ */
+
+#define LPC32XX_GPIOS 128
+
+static struct gpio_regs *regs = (struct gpio_regs *)GPIO_BASE;
+
+/**
+ * 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))
+
+/**
+ * Array of current GPIO functions. Allocated as unsigned chars to
+ * limit memory consumption.
+ */
+
+static signed char lpc32xx_function[LPC32XX_GPIOS];
+
+/**
+ * Configure a GPIO number 'offset' as input
+ */
+
+static int lpc32xx_gpio_direction_input(struct udevice *dev, unsigned offset)
+{
+	int port, mask;
+
+	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;
+	}
+
+	lpc32xx_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;
+
+	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(unsigned gpio)
+{
+	int port, mask;
+
+	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(unsigned gpio)
+{
+	int port, mask;
+
+	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(offset);
+	else
+		return gpio_clr(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;
+
+	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;
+	}
+
+	lpc32xx_function[offset] = GPIOF_OUTPUT;
+
+	return lpc32xx_gpio_set_value(dev, offset, value);
+}
+
+static int lpc32xx_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+	return lpc32xx_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 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;
+	}
+
+	/* all GPIO functions are unknown until requested */
+	memset(lpc32xx_function, GPIOF_UNKNOWN, LPC32XX_GPIOS);
+
+	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 = 0,
+};
-- 
2.1.0



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