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Message-ID: <55CC8651.2030600@ti.com>
Date: Thu, 13 Aug 2015 14:58:09 +0300
From: Roger Quadros <rogerq@...com>
To: <tony@...mide.com>
CC: <dwmw2@...radead.org>, <computersforpeace@...il.com>,
<ezequiel@...guardiasur.com.ar>, <javier@...hile0.org>,
<fcooper@...com>, <nsekhar@...com>,
<linux-mtd@...ts.infradead.org>, <linux-omap@...r.kernel.org>,
<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 16/22] memory: omap-gpmc: Support general purpose input
for WAITPINs
On 07/08/15 12:12, Roger Quadros wrote:
> 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@...com>
> ---
> drivers/memory/omap-gpmc.c | 122 +++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 117 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
> index 30d9c21..264009d 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/platform_device.h>
> #include <linux/of.h>
> @@ -223,6 +224,11 @@ struct omap3_gpmc_regs {
> struct gpmc_cs_config cs_context[GPMC_CS_NUM];
> };
>
> +struct gpmc_device {
> + struct device *dev;
> + struct gpio_chip gpio_chip;
> +};
> +
> static struct resource gpmc_mem_root;
> static struct gpmc_cs_data gpmc_cs[GPMC_CS_NUM];
> static DEFINE_SPINLOCK(gpmc_mem_lock);
> @@ -1919,10 +1925,69 @@ err:
> return ret;
> }
>
> +static int gpmc_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
> +{
> + return 1; /* we're input only */
> +}
> +
> +static int gpmc_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
> +{
> + return 0; /* we're input only */
> +}
> +
> +static int gpmc_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
> + int value)
> +{
> + return -EINVAL; /* we're input only */
> +}
> +
> +static void gpmc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> +{
> +}
> +
> +static int gpmc_gpio_get(struct gpio_chip *chip, unsigned 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.dev = 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);
>
> @@ -1950,6 +2015,17 @@ static int gpmc_probe_dt(struct platform_device *pdev)
> return ret;
> }
>
> + dev_info(&pdev->dev, "num-cs %d, num-wait %d\n",
> + gpmc_cs_num, gpmc_nr_waitpins);
> +
> + 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)
> @@ -1959,6 +2035,9 @@ 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;
> @@ -1968,6 +2047,11 @@ 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)
> @@ -1975,6 +2059,7 @@ static int gpmc_probe(struct platform_device *pdev)
> int rc;
> u32 l;
> struct resource *res;
> + struct gpmc_device *gpmc;
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (res == NULL)
> @@ -2005,6 +2090,17 @@ static int gpmc_probe(struct platform_device *pdev)
> return -EINVAL;
> }
>
> + rc = gpmc_probe_dt(pdev);
> + if (rc)
> + return rc;
> +
> + gpmc = devm_kzalloc(&pdev->dev, sizeof(*gpmc), GFP_KERNEL);
> + if (!gpmc)
> + return -ENOMEM;
> +
> + gpmc->dev = &pdev->dev;
> + platform_set_drvdata(pdev, gpmc);
> +
> pm_runtime_enable(&pdev->dev);
> pm_runtime_get_sync(&pdev->dev);
>
> @@ -2032,24 +2128,40 @@ 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;
> +
>
> if (!pdev->dev.of_node) {
> gpmc_cs_num = GPMC_CS_NUM;
> gpmc_nr_waitpins = GPMC_NR_WAITPINS;
> }
The above if {} needs to move near gpmc_probe_dt()
else we break gpmc for legacy boot.
cheers,
-roger
>
> - rc = gpmc_probe_dt(pdev);
> + rc = gpmc_probe_dt_children(pdev);
> if (rc < 0) {
> - pm_runtime_put_sync(&pdev->dev);
> - dev_err(gpmc_dev, "failed to probe DT parameters\n");
> - return rc;
> + dev_err(gpmc_dev, "failed to probe DT children\n");
> + goto dt_children_failed;
> }
>
> return 0;
> +
> +dt_children_failed:
> + gpmc_gpio_exit(gpmc);
> +gpio_init_failed:
> + gpmc_mem_exit();
> + pm_runtime_put_sync(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> + gpmc_dev = NULL;
> +
> + return rc;
> }
>
> static int gpmc_remove(struct platform_device *pdev)
> {
> + struct gpmc_device *gpmc = platform_get_drvdata(pdev);
> +
> + gpmc_gpio_exit(gpmc);
> gpmc_mem_exit();
> pm_runtime_put_sync(&pdev->dev);
> pm_runtime_disable(&pdev->dev);
>
--
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