[PATCH v6 13/17] memory: omap-gpmc: Support general purpose input for WAITPINs
Roger Quadros
rogerq at ti.com
Thu Apr 7 03:08:31 PDT 2016
OMAPs can have 2 to 4 WAITPINs that can be used as general purpose
input if not used for memory wait state insertion.
The first user will be the OMAP NAND chip to get the NAND
read/busy status using gpiolib.
Signed-off-by: Roger Quadros <rogerq at ti.com>
---
.../bindings/memory-controllers/omap-gpmc.txt | 6 ++
drivers/memory/Kconfig | 1 +
drivers/memory/omap-gpmc.c | 117 ++++++++++++++++++---
3 files changed, 112 insertions(+), 12 deletions(-)
diff --git a/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt b/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt
index 13f1378..97e7192 100644
--- a/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt
+++ b/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt
@@ -38,6 +38,10 @@ Required properties:
0 - NAND_fifoevent
1 - NAND_termcount
- interrupt-cells: Must be set to 2
+ - gpio-controller: The GPMC driver implements a GPIO controller for the
+ GPMC WAIT pins that can be used as general purpose inputs.
+ 0 maps to GPMC_WAIT0 pin.
+ - gpio-cells: Must be set to 2
Timing properties for child nodes. All are optional and default to 0.
@@ -138,6 +142,8 @@ Example for an AM33xx board:
ranges = <0 0 0x08000000 0x10000000>; /* CS0 @addr 0x8000000, size 0x10000000 */
interrupt-controller;
#interrupt-cells = <2>;
+ gpio-controller;
+ #gpio-cells = <2>;
/* child nodes go here */
};
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 51d5cd2..a9b1c14 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -51,6 +51,7 @@ config TI_EMIF
config OMAP_GPMC
bool
+ select GPIOLIB
help
This driver is for the General Purpose Memory Controller (GPMC)
present on Texas Instruments SoCs (e.g. OMAP2+). GPMC allows
diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
index bfe4e87..4dd1c65 100644
--- a/drivers/memory/omap-gpmc.c
+++ b/drivers/memory/omap-gpmc.c
@@ -21,6 +21,7 @@
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/module.h>
+#include <linux/gpio/driver.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/platform_device.h>
@@ -237,6 +238,7 @@ struct gpmc_device {
struct device *dev;
int irq;
struct irq_chip irq_chip;
+ struct gpio_chip gpio_chip;
};
static struct irq_domain *gpmc_irq_domain;
@@ -2064,10 +2066,71 @@ err:
return ret;
}
+static int gpmc_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+ return 1; /* we're input only */
+}
+
+static int gpmc_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ return 0; /* we're input only */
+}
+
+static int gpmc_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ return -EINVAL; /* we're input only */
+}
+
+static void gpmc_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+}
+
+static int gpmc_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ u32 reg;
+
+ offset += 8;
+
+ reg = gpmc_read_reg(GPMC_STATUS) & BIT(offset);
+
+ return !!reg;
+}
+
+static int gpmc_gpio_init(struct gpmc_device *gpmc)
+{
+ int ret;
+
+ gpmc->gpio_chip.parent = gpmc->dev;
+ gpmc->gpio_chip.owner = THIS_MODULE;
+ gpmc->gpio_chip.label = DEVICE_NAME;
+ gpmc->gpio_chip.ngpio = gpmc_nr_waitpins;
+ gpmc->gpio_chip.get_direction = gpmc_gpio_get_direction;
+ gpmc->gpio_chip.direction_input = gpmc_gpio_direction_input;
+ gpmc->gpio_chip.direction_output = gpmc_gpio_direction_output;
+ gpmc->gpio_chip.set = gpmc_gpio_set;
+ gpmc->gpio_chip.get = gpmc_gpio_get;
+ gpmc->gpio_chip.base = -1;
+
+ ret = gpiochip_add(&gpmc->gpio_chip);
+ if (ret < 0) {
+ dev_err(gpmc->dev, "could not register gpio chip: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void gpmc_gpio_exit(struct gpmc_device *gpmc)
+{
+ gpiochip_remove(&gpmc->gpio_chip);
+}
+
static int gpmc_probe_dt(struct platform_device *pdev)
{
int ret;
- struct device_node *child;
const struct of_device_id *of_id =
of_match_device(gpmc_dt_ids, &pdev->dev);
@@ -2095,6 +2158,14 @@ static int gpmc_probe_dt(struct platform_device *pdev)
return ret;
}
+ return 0;
+}
+
+static int gpmc_probe_dt_children(struct platform_device *pdev)
+{
+ int ret;
+ struct device_node *child;
+
for_each_available_child_of_node(pdev->dev.of_node, child) {
if (!child->name)
@@ -2104,6 +2175,9 @@ static int gpmc_probe_dt(struct platform_device *pdev)
ret = gpmc_probe_onenand_child(pdev, child);
else
ret = gpmc_probe_generic_child(pdev, child);
+
+ if (ret)
+ return ret;
}
return 0;
@@ -2113,6 +2187,11 @@ static int gpmc_probe_dt(struct platform_device *pdev)
{
return 0;
}
+
+static int gpmc_probe_dt_children(struct platform_device *pdev)
+{
+ return 0;
+}
#endif
static int gpmc_probe(struct platform_device *pdev)
@@ -2159,6 +2238,15 @@ static int gpmc_probe(struct platform_device *pdev)
return -EINVAL;
}
+ if (pdev->dev.of_node) {
+ rc = gpmc_probe_dt(pdev);
+ if (rc)
+ return rc;
+ } else {
+ gpmc_cs_num = GPMC_CS_NUM;
+ gpmc_nr_waitpins = GPMC_NR_WAITPINS;
+ }
+
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
@@ -2184,29 +2272,33 @@ static int gpmc_probe(struct platform_device *pdev)
GPMC_REVISION_MINOR(l));
gpmc_mem_init();
+ rc = gpmc_gpio_init(gpmc);
+ if (rc)
+ goto gpio_init_failed;
rc = gpmc_setup_irq(gpmc);
if (rc) {
dev_err(gpmc->dev, "gpmc_setup_irq failed\n");
- goto fail;
+ goto setup_irq_failed;
}
- if (!pdev->dev.of_node) {
- gpmc_cs_num = GPMC_CS_NUM;
- gpmc_nr_waitpins = GPMC_NR_WAITPINS;
- }
-
- rc = gpmc_probe_dt(pdev);
+ rc = gpmc_probe_dt_children(pdev);
if (rc < 0) {
- dev_err(gpmc->dev, "failed to probe DT parameters\n");
- gpmc_free_irq(gpmc);
- goto fail;
+ dev_err(gpmc->dev, "failed to probe DT children\n");
+ goto dt_children_failed;
}
return 0;
-fail:
+dt_children_failed:
+ gpmc_free_irq(gpmc);
+setup_irq_failed:
+ gpmc_gpio_exit(gpmc);
+gpio_init_failed:
+ gpmc_mem_exit();
pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
return rc;
}
@@ -2215,6 +2307,7 @@ static int gpmc_remove(struct platform_device *pdev)
struct gpmc_device *gpmc = platform_get_drvdata(pdev);
gpmc_free_irq(gpmc);
+ gpmc_gpio_exit(gpmc);
gpmc_mem_exit();
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
--
2.5.0
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