[U-Boot] [RFC PATCH] gpio: Add support for microblaze xilinx GPIO
Simon Glass
sjg at chromium.org
Sat Apr 27 17:45:53 CEST 2013
Hi Michal,
On Wed, Apr 24, 2013 at 1:27 AM, Michal Simek <michal.simek at xilinx.com> wrote:
> Microblaze uses gpio which is connected to the system reset.
> Currently gpio subsystem wasn't used for it.
>
> Add gpio driver and change Microblaze reset logic to be done
> via gpio subsystem.
>
> There are various configurations which Microblaze can have
> that's why gpio_alloc/gpio_alloc_dual(for dual channel)
> function has been introduced and gpio can be allocated
> dynamically.
>
> Adding several gpios IP is also possible and supported.
>
> For listing gpio configuration please use "gpio status" command
>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
> arch/microblaze/include/asm/gpio.h | 50 +---
> .../xilinx/microblaze-generic/microblaze-generic.c | 17 +-
> drivers/gpio/Makefile | 1 +
> drivers/gpio/xilinx_gpio.c | 323 +++++++++++++++++++++
> include/configs/microblaze-generic.h | 3 +-
> 5 files changed, 353 insertions(+), 41 deletions(-)
> create mode 100644 drivers/gpio/xilinx_gpio.c
>
> diff --git a/arch/microblaze/include/asm/gpio.h b/arch/microblaze/include/asm/gpio.h
> index 883f4d4..69df8c5 100644
> --- a/arch/microblaze/include/asm/gpio.h
> +++ b/arch/microblaze/include/asm/gpio.h
> @@ -1,41 +1,21 @@
> #ifndef _ASM_MICROBLAZE_GPIO_H_
> #define _ASM_MICROBLAZE_GPIO_H_
>
> -#include <asm/io.h>
> +/* Allocation functions */
> +extern int gpio_alloc_dual(u32 baseaddr, const char *name, u32 gpio_no0,
> + u32 gpio_no1);
> +extern int gpio_alloc(u32 baseaddr, const char *name, u32 gpio_no);
> +
> +/* Standard functions */
> +extern int gpio_request(unsigned gpio, const char *label);
> +extern int gpio_free(unsigned gpio);
> +extern int gpio_direction_input(unsigned gpio);
> +extern int gpio_direction_output(unsigned gpio, int value);
> +extern int gpio_get_value(unsigned gpio);
> +extern int gpio_set_value(unsigned gpio, int value);
> +extern int gpio_is_valid(int number);
You should just be able to include <asm-generic/gpio.h> for these.
> +#define gpio_status() gpio_info()
> +extern void gpio_info(void);
>
> -static inline int gpio_request(unsigned gpio, const char *label)
> -{
> - return 0;
> -}
> -
> -static inline int gpio_free(unsigned gpio)
> -{
> - return 0;
> -}
> -
> -static inline int gpio_direction_input(unsigned gpio)
> -{
> - return 0;
> -}
> -
> -static inline int gpio_direction_output(unsigned gpio, int value)
> -{
> - return 0;
> -}
> -
> -static inline int gpio_get_value(unsigned gpio)
> -{
> - return 0;
> -}
> -
> -static inline int gpio_set_value(unsigned gpio, int value)
> -{
> - return 0;
> -}
> -
> -static inline int gpio_is_valid(int number)
> -{
> - return 0;
> -}
> #endif
>
> diff --git a/board/xilinx/microblaze-generic/microblaze-generic.c b/board/xilinx/microblaze-generic/microblaze-generic.c
> index befbb3a..2f5f20e 100644
> --- a/board/xilinx/microblaze-generic/microblaze-generic.c
> +++ b/board/xilinx/microblaze-generic/microblaze-generic.c
> @@ -31,12 +31,17 @@
> #include <asm/processor.h>
> #include <asm/microblaze_intc.h>
> #include <asm/asm.h>
> +#include <asm/gpio.h>
> +
> +#ifdef CONFIG_XILINX_GPIO
> +static int reset_pin = -1;
> +#endif
>
> int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> {
> -#ifdef CONFIG_SYS_GPIO_0
> - *((unsigned long *)(CONFIG_SYS_GPIO_0_ADDR)) =
> - ++(*((unsigned long *)(CONFIG_SYS_GPIO_0_ADDR)));
> +#ifdef CONFIG_XILINX_GPIO
> + if (reset_pin != -1)
> + gpio_direction_output(reset_pin, 1);
> #endif
>
> #ifdef CONFIG_XILINX_TB_WATCHDOG
> @@ -52,8 +57,10 @@ int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>
> int gpio_init (void)
> {
> -#ifdef CONFIG_SYS_GPIO_0
> - *((unsigned long *)(CONFIG_SYS_GPIO_0_ADDR)) = 0xFFFFFFFF;
> +#ifdef CONFIG_XILINX_GPIO
> + reset_pin = gpio_alloc(CONFIG_SYS_GPIO_0_ADDR, "reset", 1);
> + if (reset_pin != -1)
> + gpio_request(reset_pin, "reset_pin");
> #endif
> return 0;
> }
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 9df1e26..830e8e6 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -47,6 +47,7 @@ COBJS-$(CONFIG_OMAP_GPIO) += omap_gpio.o
> COBJS-$(CONFIG_DB8500_GPIO) += db8500_gpio.o
> COBJS-$(CONFIG_BCM2835_GPIO) += bcm2835_gpio.o
> COBJS-$(CONFIG_S3C2440_GPIO) += s3c2440_gpio.o
> +COBJS-$(CONFIG_XILINX_GPIO) += xilinx_gpio.o
>
> COBJS := $(COBJS-y)
> SRCS := $(COBJS:.o=.c)
> diff --git a/drivers/gpio/xilinx_gpio.c b/drivers/gpio/xilinx_gpio.c
> new file mode 100644
> index 0000000..f2c289f
> --- /dev/null
> +++ b/drivers/gpio/xilinx_gpio.c
> @@ -0,0 +1,323 @@
> +/*
> + * Copyright (c) 2013 Xilinx, Michal Simek
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <errno.h>
> +#include <malloc.h>
> +#include <linux/list.h>
> +#include <asm/io.h>
> +#include <asm/gpio.h>
> +
> +static LIST_HEAD(gpio_list);
> +
> +enum gpio_direction {
> + GPIO_DIRECTION_OUT = 0,
> + GPIO_DIRECTION_IN = 1,
> +};
> +
> +/* Gpio simple map */
> +struct gpio_regs {
> + u32 gpiodata;
> + u32 gpiodir;
> +};
> +
> +#define GPIO_NAME_SIZE 10
> +
> +struct gpio_names {
> + char name[GPIO_NAME_SIZE];
> +};
> +
> +/* Initialized, rxbd_current, rx_first_buf must be 0 after init */
> +struct xilinx_gpio_priv {
> + struct gpio_regs *regs;
> + u32 gpio_min;
> + u32 gpio_max;
> + u32 gpiodata_store;
> + char name[GPIO_NAME_SIZE];
> + struct list_head list;
> + struct gpio_names *gpio_name;
> +};
> +
> +/* Store number of allocated gpio pins */
> +static u32 xilinx_gpio_max;
> +
> +/* Get associated gpio controller */
> +static struct xilinx_gpio_priv *gpio_get_controller(unsigned gpio)
> +{
> + struct list_head *entry;
> + struct xilinx_gpio_priv *priv = NULL;
> +
> + list_for_each(entry, &gpio_list) {
> + priv = list_entry(entry, struct xilinx_gpio_priv, list);
> + if (gpio >= priv->gpio_min && gpio <= priv->gpio_max) {
> + debug("%s: reg: %x, min-max: %d-%d\n", __func__,
> + (u32)priv->regs, priv->gpio_min, priv->gpio_max);
> + return priv;
> + }
> + }
> + puts("!!!Can't get gpio controller!!!\n");
> + return NULL;
> +}
> +
> +/* Get gpio pin name if used/setup */
> +static char *get_name(unsigned gpio)
> +{
> + u32 gpio_priv;
> + debug("%s\n", __func__);
> +
> + struct xilinx_gpio_priv *priv = gpio_get_controller(gpio);
It looks like gpio_get_controller() can return NULL, but you use it anyway?
> + gpio_priv = gpio - priv->gpio_min;
> +
> + return *priv->gpio_name[gpio_priv].name ?
> + priv->gpio_name[gpio_priv].name : "UNKNOWN";
> +}
> +
> +/* Get output value */
> +static int gpio_get_output_value(unsigned gpio)
> +{
> + u32 val, gpio_priv;
> + struct xilinx_gpio_priv *priv = gpio_get_controller(gpio);
> +
> + gpio_priv = gpio - priv->gpio_min;
> + val = !!(priv->gpiodata_store & (1 << gpio_priv));
> + debug("%s: reg: %x, gpio_no: %d, dir: %d\n", __func__,
> + (u32)priv->regs, gpio_priv, val);
> +
> + return val;
> +}
> +
> +/* Get input value */
> +static int gpio_get_input_value(unsigned gpio)
> +{
> + u32 val, gpio_priv;
> + struct xilinx_gpio_priv *priv = gpio_get_controller(gpio);
> + struct gpio_regs *regs = priv->regs;
> +
> + gpio_priv = gpio - priv->gpio_min;
> + val = readl(®s->gpiodata);
> + val = !!(val & (1 << gpio_priv));
> + debug("%s: reg: %x, gpio_no: %d, dir: %d\n", __func__,
> + (u32)priv->regs, gpio_priv, val);
> +
> + return val;
> +}
> +
> +/* Set gpio direction */
> +static int gpio_set_direction(unsigned gpio, enum gpio_direction direction)
> +{
> + u32 val, gpio_priv;
> + struct xilinx_gpio_priv *priv = gpio_get_controller(gpio);
> + struct gpio_regs *regs = priv->regs;
> +
> + val = readl(®s->gpiodir);
> +
> + gpio_priv = gpio - priv->gpio_min;
> + if (direction == GPIO_DIRECTION_OUT)
> + val &= ~(1 << gpio_priv);
> + else
> + val |= 1 << gpio_priv;
> +
> + writel(val, ®s->gpiodir);
> + debug("%s: reg: %x, gpio_no: %d, dir: %d\n", __func__,
> + (u32)priv->regs, gpio_priv, val);
> +
> + return 0;
> +}
> +
> +/* Get gpio direction */
> +static int gpio_get_direction(unsigned gpio)
> +{
> + u32 val, gpio_priv;
> + struct xilinx_gpio_priv *priv = gpio_get_controller(gpio);
> + struct gpio_regs *regs = priv->regs;
> +
> + gpio_priv = gpio - priv->gpio_min;
> + val = readl(®s->gpiodir);
> + val = !!(val & (1 << gpio_priv));
> + debug("%s: reg: %x, gpio_no: %d, dir: %d\n", __func__,
> + (u32)priv->regs, gpio_priv, val);
> +
> + return val;
> +}
> +
> +/*
> + * Get input value
> + * for example gpio setup to output only can't get input value
> + * which is breaking gpio toggle command
> + */
> +int gpio_get_value(unsigned gpio)
> +{
> + u32 val;
> +
> + if (gpio_get_direction(gpio) == GPIO_DIRECTION_OUT)
> + val = gpio_get_output_value(gpio);
> + else
> + val = gpio_get_input_value(gpio);
> +
> + return val;
> +}
> +
> +/* Set output value */
> +int gpio_set_output_value(unsigned gpio, int value)
> +{
> + u32 val, gpio_priv;
> + struct xilinx_gpio_priv *priv = gpio_get_controller(gpio);
> + struct gpio_regs *regs = priv->regs;
> +
> + gpio_priv = gpio - priv->gpio_min;
> + val = priv->gpiodata_store;
> + if (value)
> + val |= 1 << gpio_priv;
> + else
> + val &= ~(1 << gpio_priv);
> +
> + writel(val, ®s->gpiodata);
> + debug("%s: reg: %x, gpio_no: %d, output_val: %d\n", __func__,
> + (u32)priv->regs, gpio_priv, val);
> + priv->gpiodata_store = val;
> +
> + return 0;
> +}
> +
> +/* Set GPIO as input */
> +int gpio_direction_input(unsigned gpio)
> +{
> + debug("%s\n", __func__);
> + return gpio_set_direction(gpio, GPIO_DIRECTION_IN);
> +}
> +
> +/* Setup GPIO as output and set output value */
> +int gpio_direction_output(unsigned gpio, int value)
> +{
> + int ret = gpio_set_direction(gpio, GPIO_DIRECTION_OUT);
> +
> + debug("%s\n", __func__);
> +
> + if (ret < 0)
> + return ret;
> +
> + gpio_set_output_value(gpio, value);
> + return 0;
> +}
> +
> +/* Show gpio status */
> +void gpio_info(void)
> +{
> + unsigned gpio;
> +
> + struct list_head *entry;
> + struct xilinx_gpio_priv *priv = NULL;
> +
> + list_for_each(entry, &gpio_list) {
> + priv = list_entry(entry, struct xilinx_gpio_priv, list);
> + printf("\n%s: %s/%x (%d-%d)\n", __func__, priv->name,
> + (u32)priv->regs, priv->gpio_min, priv->gpio_max);
> +
> + for (gpio = priv->gpio_min; gpio <= priv->gpio_max; gpio++) {
> + printf("GPIO_%d:\t%s is an ", gpio, get_name(gpio));
> + if (gpio_get_direction(gpio) == GPIO_DIRECTION_OUT)
> + printf("OUTPUT value = %d\n",
> + gpio_get_output_value(gpio));
> + else
> + printf("INPUT value = %d\n",
> + gpio_get_input_value(gpio));
> + }
> + }
> +}
> +
> +
> +int gpio_request(unsigned gpio, const char *label)
> +{
> + u32 gpio_priv;
> + struct xilinx_gpio_priv *priv;
> +
> + if (gpio >= xilinx_gpio_max)
> + return -EINVAL;
> +
> + priv = gpio_get_controller(gpio);
> + gpio_priv = gpio - priv->gpio_min;
> +
> + if (label != NULL) {
> + strncpy(priv->gpio_name[gpio_priv].name, label, GPIO_NAME_SIZE);
> + priv->gpio_name[gpio_priv].name[GPIO_NAME_SIZE - 1] = '\0';
> + }
> +
> + return 0;
> +}
> +
> +int gpio_free(unsigned gpio)
> +{
> + u32 gpio_priv;
> + struct xilinx_gpio_priv *priv;
> +
> + if (gpio >= xilinx_gpio_max)
> + return -EINVAL;
> +
> + priv = gpio_get_controller(gpio);
> + gpio_priv = gpio - priv->gpio_min;
> + priv->gpio_name[gpio_priv].name[0] = '\0';
> +
> + /* Do nothing here */
> + return 0;
> +}
> +
> +
> +int gpio_alloc(u32 baseaddr, const char *name, u32 gpio_no)
> +{
> + struct xilinx_gpio_priv *priv;
> +
> + priv = calloc(1, sizeof(struct xilinx_gpio_priv));
> +
> + /* Setup gpio name */
> + if (name != NULL) {
> + strncpy(priv->name, name, GPIO_NAME_SIZE);
> + priv->name[GPIO_NAME_SIZE - 1] = '\0';
> + }
> + priv->regs = (struct gpio_regs *)baseaddr;
> +
> + priv->gpio_min = xilinx_gpio_max;
> + xilinx_gpio_max = priv->gpio_min + gpio_no;
> + priv->gpio_max = xilinx_gpio_max - 1;
> +
> + priv->gpio_name = calloc(gpio_no, sizeof(struct gpio_names));
> +
> + INIT_LIST_HEAD(&priv->list);
> + list_add_tail(&priv->list, &gpio_list);
> +
> + printf("%s: Add %s (%d-%d)\n", __func__, name,
> + priv->gpio_min, priv->gpio_max);
> +
> + /* Return the first gpio allocated for this device */
> + return priv->gpio_min;
> +}
In terms of allocation, is this function intended to tell the GPIO
driver that there are new GPIOs available?
For device tree the GPIO banks can be split into individual nodes each
with the same compatible string. Then during device init you can build
a table of available GPIOs. Each bank gets a phandle so that it can be
used elsewhere. For example you might do:
gpio-controllers {
gpa: gpio-a {
compatible = "xilinx,gpio-controller";
reg = <some_address size>;
};
gpb: gpio-b {
compatible = "xilinx,gpio-controller";
reg = <some_address size>;
};
};
example-peripheral {
gpios = <&gpa 5 ...>, <&gpb 6 ...>;
};
The exact binding of GPIOs is up to you - use the same one as Linux if
you have one there.
Regards,
Simon
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