lpc32xx: add GPIO support

This driver only supports Driver Model, not legacy model.

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

diff --git a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
index 81b53eaa6ded9787002660adcdece01aecedb8e6..a407098edac01a5c042e3589f857219c345cf696 100644 (file)
--- 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 (file)
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@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/Kconfig b/drivers/gpio/Kconfig
index b609e73bbaf5fe4993b6a560ef9101c4363ec5e2..7b5178a23a4f623b8fddc3ea2520bf9c4fca2d5f 100644 (file)
--- 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 fe9a3b23964556e18c92a985a06f1e7fcfad433d..85f71c5d4a773172ece61eecc3f9af6640231925 100644 (file)
--- 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 (file)
index 0000000..96b3125
--- /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),
+};