[U-Boot] [RFC PATCH v2 13/13] tegra: Convert tegra GPIO driver to use driver model

Simon Glass
2014-05-09T17:28:28Z

This is an implementation of GPIOs for Tegra that uses driver model. It has
been tested on trimslice and also using the new iotrace feature.

The implementation uses a top-level GPIO device (which has no actual GPIOS).
Under this all the banks are created as separate GPIO devices.

The GPIOs are named as per the Tegra datasheet/header files: A0..A7, B0..B7,
..., Z0..Z7, AA0..AA7, etc.

Since driver model is not yet available before relocation, or in SPL, a
special function is provided for seaboard's SPL code.

This series is marked RFC since the Tegra driver may need further discussion.
Signed-off-by: Simon Glass <sjg@chromium.org>
---

Changes in v3:
- Move dm command enable to previous patch
- Use gpio number for the internal helper functions

Changes in v2:
- Split out driver model changes into separate patches
- Correct bugs found during testing

arch/arm/include/asm/arch-tegra/gpio.h | 14 +-
board/nvidia/seaboard/seaboard.c | 2 +-
drivers/gpio/tegra_gpio.c | 313 +++++++++++++++++++++++++++------
include/configs/tegra-common.h | 1 +
4 files changed, 266 insertions(+), 64 deletions(-)

diff --git a/arch/arm/include/asm/arch-tegra/gpio.h b/arch/arm/include/asm/arch-tegra/gpio.h
index d97190d..80e4a73 100644
--- a/arch/arm/include/asm/arch-tegra/gpio.h
+++ b/arch/arm/include/asm/arch-tegra/gpio.h
@@ -6,6 +6,8 @@
#ifndef _TEGRA_GPIO_H_
#define _TEGRA_GPIO_H_

+#define TEGRA_GPIOS_PER_PORT 8
+#define TEGRA_PORTS_PER_BANK 4
#define MAX_NUM_GPIOS (TEGRA_GPIO_PORTS * TEGRA_GPIO_BANKS * 8)
#define GPIO_NAME_SIZE 20 /* gpio_request max label len */

@@ -14,11 +16,13 @@
#define GPIO_FULLPORT(x) ((x) >> 3)
#define GPIO_BIT(x) ((x) & 0x7)

-/*
- * Tegra-specific GPIO API
+/**
+ * tegra_spl_gpio_direction_output() - set the output value of a GPIO
+ *
+ * This function is only used from SPL on seaboard, which needs to enable a
+ * GPIO to get the UART running. It could be done in U-Boot rather than SPL,
+ * but for now, this gets it working
*/
+int tegra_spl_gpio_direction_output(int gpio, int value);

-void gpio_info(void);
-
-#define gpio_status() gpio_info()
#endif /* TEGRA_GPIO_H_ */
diff --git a/board/nvidia/seaboard/seaboard.c b/board/nvidia/seaboard/seaboard.c
index ef4e481..e27efcd 100644
--- a/board/nvidia/seaboard/seaboard.c
+++ b/board/nvidia/seaboard/seaboard.c
@@ -22,7 +22,7 @@ void gpio_early_init_uart(void)
#ifndef CONFIG_SPL_BUILD
gpio_request(GPIO_PI3, NULL);
#endif
- gpio_direction_output(GPIO_PI3, 0);
+ tegra_spl_gpio_direction_output(GPIO_PI3, 0);
}
#endif

diff --git a/drivers/gpio/tegra_gpio.c b/drivers/gpio/tegra_gpio.c
index 82b30d5..f03d4ed 100644
--- a/drivers/gpio/tegra_gpio.c
+++ b/drivers/gpio/tegra_gpio.c
@@ -12,10 +12,17 @@
*/

#include <common.h>
+#include <dm.h>
+#include <malloc.h>
+#include <errno.h>
+#include <fdtdec.h>
#include <asm/io.h>
#include <asm/bitops.h>
#include <asm/arch/tegra.h>
#include <asm/gpio.h>
+#include <dm/device-internal.h>
+
+DECLARE_GLOBAL_DATA_PTR;

enum {
TEGRA_CMD_INFO,
@@ -24,14 +31,18 @@ enum {
TEGRA_CMD_INPUT,
};

-static struct gpio_names {
- char name[GPIO_NAME_SIZE];
-} gpio_names[MAX_NUM_GPIOS];
+struct tegra_gpio_platdata {
+ struct gpio_ctlr_bank *bank;
+ const char *port_name; /* Name of port, e.g. "B" */
+ int base_port; /* Port number for this port (0, 1,.., n-1) */
+};

-static char *get_name(int i)
-{
- return *gpio_names[i].name ? gpio_names[i].name : "UNKNOWN";
-}
+/* Information about each port at run-time */
+struct tegra_port_info {
+ char label[TEGRA_GPIOS_PER_PORT][GPIO_NAME_SIZE];
+ struct gpio_ctlr_bank *bank;
+ int base_port; /* Port number for this port (0, 1,.., n-1) */
+};

/* Return config of pin 'gpio' as GPIO (1) or SFPIO (0) */
static int get_config(unsigned gpio)
@@ -121,38 +132,71 @@ static void set_level(unsigned gpio, int high)
writel(u, &bank->gpio_out[GPIO_PORT(gpio)]);
}

+static int check_reserved(struct device *dev, unsigned offset,
+ const char *func)
+{
+ struct tegra_port_info *state = dev_get_priv(dev);
+ struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+
+ if (!*state->label[offset]) {
+ printf("tegra_gpio: %s: error: gpio %s%d not reserved\n",
+ func, uc_priv->bank_name, offset);
+ return -EPERM;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_SPL
+/* set GPIO pin 'gpio' as an output, with polarity 'value' */
+int tegra_spl_gpio_direction_output(int gpio, int value)
+{
+ /* Configure GPIO output value. */
+ set_level(gpio, value);
+
+ /* Configure GPIO direction as output. */
+ set_direction(gpio, value);
+
+ return 0;
+}
+#endif /* CONFIG_SPL */
+
/*
* Generic_GPIO primitives.
*/

-int gpio_request(unsigned gpio, const char *label)
+static int tegra_gpio_request(struct device *dev, unsigned offset,
+ const char *label)
{
- if (gpio >= MAX_NUM_GPIOS)
- return -1;
+ struct tegra_port_info *state = dev_get_priv(dev);

- if (label != NULL) {
- strncpy(gpio_names[gpio].name, label, GPIO_NAME_SIZE);
- gpio_names[gpio].name[GPIO_NAME_SIZE - 1] = '\0';
- }
+ if (*state->label[offset])
+ return -EBUSY;
+
+ strncpy(state->label[offset], label, GPIO_NAME_SIZE);
+ state->label[offset][GPIO_NAME_SIZE - 1] = '\0';

/* Configure as a GPIO */
- set_config(gpio, 1);
+ set_config(state->base_port + offset, 1);

return 0;
}

-int gpio_free(unsigned gpio)
+static int tegra_gpio_free(struct device *dev, unsigned offset)
{
- if (gpio >= MAX_NUM_GPIOS)
- return -1;
+ struct tegra_port_info *state = dev_get_priv(dev);
+ int ret;
+
+ ret = check_reserved(dev, offset, __func__);
+ if (ret)
+ return ret;
+ state->label[offset][0] = '\0';

- gpio_names[gpio].name[0] = '\0';
- /* Do not configure as input or change pin mux here */
return 0;
}

/* read GPIO OUT value of pin 'gpio' */
-static int gpio_get_output_value(unsigned gpio)
+static int tegra_gpio_get_output_value(unsigned gpio)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
@@ -166,81 +210,234 @@ static int gpio_get_output_value(unsigned gpio)
return (val >> GPIO_BIT(gpio)) & 1;
}

+
/* set GPIO pin 'gpio' as an input */
-int gpio_direction_input(unsigned gpio)
+static int tegra_gpio_direction_input(struct device *dev, unsigned offset)
{
- debug("gpio_direction_input: pin = %d (port %d:bit %d)\n",
- gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
+ struct tegra_port_info *state = dev_get_priv(dev);
+ int ret;
+
+ ret = check_reserved(dev, offset, __func__);
+ if (ret)
+ return ret;

/* Configure GPIO direction as input. */
- set_direction(gpio, 0);
+ set_direction(state->base_port + offset, 0);

return 0;
}

/* set GPIO pin 'gpio' as an output, with polarity 'value' */
-int gpio_direction_output(unsigned gpio, int value)
+static int tegra_gpio_direction_output(struct device *dev, unsigned offset,
+ int value)
{
- debug("gpio_direction_output: pin = %d (port %d:bit %d) = %s\n",
- gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio),
- value ? "HIGH" : "LOW");
+ struct tegra_port_info *state = dev_get_priv(dev);
+ int ret;
+
+ ret = check_reserved(dev, offset, __func__);
+ if (ret)
+ return ret;

/* Configure GPIO output value. */
- set_level(gpio, value);
+ set_level(state->base_port + offset, value);

/* Configure GPIO direction as output. */
- set_direction(gpio, 1);
+ set_direction(state->base_port + offset, 1);

return 0;
}

/* read GPIO IN value of pin 'gpio' */
-int gpio_get_value(unsigned gpio)
+static int tegra_gpio_get_value(struct device *dev, unsigned offset)
{
- struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
- struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
+ struct tegra_port_info *state = dev_get_priv(dev);
+ int gpio = state->base_port + offset;
+ int ret;
int val;

- debug("gpio_get_value: pin = %d (port %d:bit %d)\n",
- gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
+ ret = check_reserved(dev, offset, __func__);
+ if (ret)
+ return ret;
+
+ debug("%s: pin = %d (port %d:bit %d)\n", __func__,
+ gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));

- val = readl(&bank->gpio_in[GPIO_PORT(gpio)]);
+ val = readl(&state->bank->gpio_in[GPIO_PORT(gpio)]);

return (val >> GPIO_BIT(gpio)) & 1;
}

/* write GPIO OUT value to pin 'gpio' */
-int gpio_set_value(unsigned gpio, int value)
+static int tegra_gpio_set_value(struct device *dev, unsigned offset, int value)
{
+ struct tegra_port_info *state = dev_get_priv(dev);
+ int gpio = state->base_port + offset;
+ int ret;
+
+ ret = check_reserved(dev, offset, __func__);
+ if (ret)
+ return ret;
+
debug("gpio_set_value: pin = %d (port %d:bit %d), value = %d\n",
- gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio), value);
+ gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio), value);

/* Configure GPIO output value. */
- set_level(gpio, value);
+ set_level(state->base_port + offset, value);

return 0;
}

-/*
- * Display Tegra GPIO information
+static int tegra_gpio_get_state(struct device *dev, unsigned int offset,
+ char *buf, int bufsize)
+{
+ struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+ struct tegra_port_info *state = dev_get_priv(dev);
+ int gpio = state->base_port + offset;
+ const char *label;
+ int is_output;
+ int is_gpio;
+ int size;
+
+ label = state->label[offset];
+ is_gpio = get_config(state->base_port + offset); /* GPIO, not SFPIO */
+ size = snprintf(buf, bufsize, "%s%d: ",
+ uc_priv->bank_name ? uc_priv->bank_name : "", offset);
+ buf += size;
+ bufsize -= size;
+ if (is_gpio) {
+ is_output = get_direction(gpio);
+
+ snprintf(buf, bufsize, "%s: %d [%c]%s%s",
+ is_output ? "out" : " in",
+ is_output ?
+ tegra_gpio_get_output_value(gpio) :
+ tegra_gpio_get_value(dev, offset),
+ *label ? 'x' : ' ',
+ *label ? " " : "",
+ label);
+ } else {
+ snprintf(buf, bufsize, "sfpio");
+ }
+
+ return 0;
+}
+
+static const struct dm_gpio_ops gpio_tegra_ops = {
+ .request = tegra_gpio_request,
+ .free = tegra_gpio_free,
+ .direction_input = tegra_gpio_direction_input,
+ .direction_output = tegra_gpio_direction_output,
+ .get_value = tegra_gpio_get_value,
+ .set_value = tegra_gpio_set_value,
+ .get_state = tegra_gpio_get_state,
+};
+
+/**
+ * Returns the name of a GPIO port
+ *
+ * GPIOs are named A, B, C, ..., Z, AA, BB, CC, ...
+ *
+ * @base_port: Base port number (0, 1..n-1)
+ * @return allocated string containing the name
*/
-void gpio_info(void)
+static char *gpio_port_name(int base_port)
{
- unsigned c;
- int type;
+ char *name, *s;
+
+ name = malloc(3);
+ if (name) {
+ s = name;
+ *s++ = 'A' + (base_port % 26);
+ if (base_port >= 26)
+ *s++ = *name;
+ *s = '\0';
+ }
+
+ return name;
+}
+
+static const struct device_id tegra_gpio_ids[] = {
+ { .compatible = "nvidia,tegra30-gpio" },
+ { .compatible = "nvidia,tegra20-gpio" },
+ { }
+};
+
+static int gpio_tegra_probe(struct device *dev)
+{
+ struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+ struct tegra_port_info *priv = dev->priv;
+ struct tegra_gpio_platdata *plat = dev->platdata;

- for (c = 0; c < MAX_NUM_GPIOS; c++) {
- type = get_config(c); /* GPIO, not SFPIO */
- if (type) {
- printf("GPIO_%d:\t%s is an %s, ", c,
- get_name(c),
- get_direction(c) ? "OUTPUT" : "INPUT");
- if (get_direction(c))
- printf("value = %d", gpio_get_output_value(c));
- else
- printf("value = %d", gpio_get_value(c));
- printf("\n");
- } else
- continue;
+ /* Only child devices have ports */
+ if (!plat)
+ return 0;
+
+ priv->bank = plat->bank;
+ priv->base_port = plat->base_port;
+
+ uc_priv->gpio_count = TEGRA_GPIOS_PER_PORT;
+ uc_priv->bank_name = plat->port_name;
+
+ return 0;
+}
+
+/**
+ * We have a top-level GPIO device with no actual GPIOs. It has a child
+ * device for each Tegra port.
+ */
+static int gpio_tegra_bind(struct device *parent)
+{
+ struct tegra_gpio_platdata *plat = parent->platdata;
+ struct gpio_ctlr *ctlr;
+ int bank_count;
+ int bank;
+ int ret;
+ int len;
+
+ /* If this is a child device, there is nothing to do here */
+ if (plat)
+ return 0;
+
+ /*
+ * This driver does not make use of interrupts, other than to figure
+ * out the number of GPIO banks
+ */
+ if (!fdt_getprop(gd->fdt_blob, parent->of_offset, "interrupts", &len))
+ return -EINVAL;
+ bank_count = len / 3 / sizeof(u32);
+ ctlr = (struct gpio_ctlr *)fdtdec_get_addr(gd->fdt_blob,
+ parent->of_offset, "reg");
+ for (bank = 0; bank < bank_count; bank++) {
+ int port;
+
+ for (port = 0; port < TEGRA_PORTS_PER_BANK; port++) {
+ struct tegra_gpio_platdata *plat;
+ struct device *dev;
+
+ plat = calloc(1, sizeof(*plat));
+ if (!plat)
+ return -ENOMEM;
+ plat->bank = &ctlr->gpio_bank[bank];
+ plat->base_port = bank * TEGRA_PORTS_PER_BANK + port;
+ plat->port_name = gpio_port_name(plat->base_port);
+
+ ret = device_bind(parent, parent->driver,
+ plat->port_name, plat, -1, &dev);
+ if (ret)
+ return ret;
+ dev->of_offset = parent->of_offset;
+ }
}
+
+ return 0;
}
+
+U_BOOT_DRIVER(gpio_tegra) = {
+ .name = "gpio_tegra",
+ .id = UCLASS_GPIO,
+ .of_match = tegra_gpio_ids,
+ .bind = gpio_tegra_bind,
+ .probe = gpio_tegra_probe,
+ .priv_auto_alloc_size = sizeof(struct tegra_port_info),
+ .ops = &gpio_tegra_ops,
+};
diff --git a/include/configs/tegra-common.h b/include/configs/tegra-common.h
index 24b909b..1069218 100644
--- a/include/configs/tegra-common.h
+++ b/include/configs/tegra-common.h
@@ -21,6 +21,7 @@

#define CONFIG_DM
#define CONFIG_CMD_DM
+#define CONFIG_DM_GPIO

#define CONFIG_SYS_TIMER_RATE 1000000
#define CONFIG_SYS_TIMER_COUNTER NV_PA_TMRUS_BASE
--
1.9.1.423.g4596e3a