[PATCH v2 1/3] input: keyboad: imx: add snvs power key driver

Zhi Li lznuaa at gmail.com
Wed May 13 11:27:39 PDT 2015


On Wed, May 13, 2015 at 11:40 AM, Dmitry Torokhov
<dmitry.torokhov at gmail.com> wrote:
> Hi Frank,
>
> On Wed, May 13, 2015 at 10:47:40PM +0800, Frank.Li at freescale.com wrote:
>> From: Robin Gong <b38343 at freescale.com>
>>
>> add snvs power key driver.
>> It work in imx chips after i.mx6sx
>>
>> Signed-off-by: Robin Gong <b38343 at freescale.com>
>> Signed-off-by: Frank Li <Frank.Li at freescale.com>
>> ---
>> Change from V1 to V2
>>  - Remove SOC_IMX6SX depend
>
> No, I did not mean to remove SOC_IMX6SX completely. I was wondering if
> we should also add "depends on OF". Even if we don't add OF dpeendency I
> think we should have
>
>         depends on SOC_IMX6SX || COMPILE_TEST
>
>>  - Add "TO compile the deiver as module.. "
>>  - Change license  2015
>>  - BIT(x)
>>  - use pdev->dev.of_node
>>  - iounmap at remove
>>  - use linux,keycode
>>  - use linux,wakeup
>>  - Remove irq >=0 check at devm_regust_irq
>>  - Remove IRQF_NO_SUSPEND
>>  - Register irq after allocate device to avoid race condition
>>  - add devm_add_action to remove del_timer_sync
>>
>>  drivers/input/keyboard/Kconfig       |   9 ++
>>  drivers/input/keyboard/Makefile      |   1 +
>>  drivers/input/keyboard/snvs_pwrkey.c | 239 +++++++++++++++++++++++++++++++++++
>>  3 files changed, 249 insertions(+)
>>  create mode 100644 drivers/input/keyboard/snvs_pwrkey.c
>>
>> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
>> index 106fbac..6c1c7de 100644
>> --- a/drivers/input/keyboard/Kconfig
>> +++ b/drivers/input/keyboard/Kconfig
>> @@ -400,6 +400,15 @@ config KEYBOARD_MPR121
>>         To compile this driver as a module, choose M here: the
>>         module will be called mpr121_touchkey.
>>
>> +config KEYBOARD_SNVS_PWRKEY
>> +     tristate "IMX SNVS Power Key Driver"
>> +     help
>> +       This is the snvs powerkey driver for the Freescale i.MX application
>> +       processors that are newer than i.MX6 SX.
>> +
>> +       To compile this driver as a module, choose M here; the
>> +       module will be called snvs_pwrkey.
>> +
>>  config KEYBOARD_IMX
>>       tristate "IMX keypad support"
>>       depends on ARCH_MXC
>> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
>> index df28d55..1d416dd 100644
>> --- a/drivers/input/keyboard/Makefile
>> +++ b/drivers/input/keyboard/Makefile
>> @@ -51,6 +51,7 @@ obj-$(CONFIG_KEYBOARD_QT1070)           += qt1070.o
>>  obj-$(CONFIG_KEYBOARD_QT2160)                += qt2160.o
>>  obj-$(CONFIG_KEYBOARD_SAMSUNG)               += samsung-keypad.o
>>  obj-$(CONFIG_KEYBOARD_SH_KEYSC)              += sh_keysc.o
>> +obj-$(CONFIG_KEYBOARD_SNVS_PWRKEY)   += snvs_pwrkey.o
>>  obj-$(CONFIG_KEYBOARD_SPEAR)         += spear-keyboard.o
>>  obj-$(CONFIG_KEYBOARD_STMPE)         += stmpe-keypad.o
>>  obj-$(CONFIG_KEYBOARD_STOWAWAY)              += stowaway.o
>> diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
>> new file mode 100644
>> index 0000000..e4c2de3
>> --- /dev/null
>> +++ b/drivers/input/keyboard/snvs_pwrkey.c
>> @@ -0,0 +1,239 @@
>> +/*
>> + * Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved.
>> + *
>> + * The code contained herein is licensed under the GNU General Public
>> + * License. You may obtain a copy of the GNU General Public License
>> + * Version 2 or later at the following locations:
>> + *
>> + * http://www.opensource.org/licenses/gpl-license.html
>> + * http://www.gnu.org/copyleft/gpl.html
>> + */
>> +
>> +#include <linux/device.h>
>> +#include <linux/err.h>
>> +#include <linux/init.h>
>> +#include <linux/input.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/jiffies.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +
>> +#define SNVS_LPSR_REG        0x4C    /* LP Status Register */
>> +#define SNVS_LPCR_REG        0x38    /* LP Control Register */
>> +#define SNVS_HPSR_REG        0x14
>> +#define SNVS_HPSR_BTN        BIT(6)
>> +#define SNVS_LPSR_SPO        BIT(18)
>> +#define SNVS_LPCR_DEP_EN BIT(5)
>> +
>> +struct pwrkey_drv_data {
>> +     void __iomem *ioaddr;
>> +     int irq;
>> +     int keycode;
>> +     int keystate;  /* 1:pressed */
>> +     int wakeup;
>> +     struct timer_list check_timer;
>> +     struct input_dev *input;
>> +};
>> +
>> +static void imx_imx_snvs_check_for_events(unsigned long data)
>> +{
>> +     struct pwrkey_drv_data *pdata = (struct pwrkey_drv_data *) data;
>> +     struct input_dev *input = pdata->input;
>> +     void __iomem *ioaddr = pdata->ioaddr;
>> +     u32 state;
>> +
>> +     state = ((readl_relaxed(ioaddr + SNVS_HPSR_REG) & SNVS_HPSR_BTN) ?
>> +             1 : 0);
>> +
>> +     /* only report new event if status changed */
>> +     if (state ^ pdata->keystate) {
>> +             pdata->keystate = state;
>> +             input_event(input, EV_KEY, pdata->keycode, state);
>> +             input_sync(input);
>> +             pm_relax(pdata->input->dev.parent);
>> +     }
>> +
>> +     /* repeat check if pressed long */
>> +     if (state) {
>> +             mod_timer(&pdata->check_timer,
>> +                       jiffies + msecs_to_jiffies(60));
>
> #define for 60 please.
>
>> +     }
>> +}
>> +
>> +static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
>> +{
>> +     struct platform_device *pdev = dev_id;
>> +     struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
>> +     void __iomem *ioaddr = pdata->ioaddr;
>> +     u32 lp_status;
>> +
>> +     pm_wakeup_event(pdata->input->dev.parent, 0);
>> +     lp_status = readl_relaxed(ioaddr + SNVS_LPSR_REG);
>> +     if (lp_status & SNVS_LPSR_SPO)
>> +             mod_timer(&pdata->check_timer, jiffies + msecs_to_jiffies(2));
>
> Hmm, 2 msec is kind of low for debouncing I think. In any case please
> add a #define for it.
>
>> +
>> +     /* clear SPO status */
>> +     writel_relaxed(lp_status, ioaddr + SNVS_LPSR_REG);
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +static void imx_snvs_pwrkey_act(void *pdata)
>> +{
>> +     struct pwrkey_drv_data *pd = pdata;
>> +
>> +     del_timer_sync(&pd->check_timer);
>> +}
>> +
>> +static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
>> +{
>> +     struct pwrkey_drv_data *pdata = NULL;
>> +     struct input_dev *input = NULL;
>> +     struct device_node *np;
>> +     void __iomem *ioaddr;
>> +     u32 val;
>> +     int ret = 0;
>
> Presonal preference - can we please call this variable "error"? And you
> do not need to initialize it.
>
>> +
>> +     pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
>> +     if (!pdata)
>> +             return -ENOMEM;
>> +
>> +     /* Get SNVS register Page */
>> +     np = pdev->dev.of_node;
>> +     if (!np)
>> +             return -ENODEV;
>
> We should check it before trying to allocate memory.
>
>> +     pdata->ioaddr = of_iomap(np, 0);
>> +     if (IS_ERR(pdata->ioaddr))
>> +             return PTR_ERR(pdata->ioaddr);
>
> Umm, you are still leaking it on error path. Can you try doing:
>
>         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>         pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
>         if (IS_ERR(pdata->ioaddr))
>                 return PTR_ERR(pdata->ioaddr);
>

Thank you for comments.
but I don't use of_iomap here because the resource is shared with the
other device.

SNVS included a rtc, a power off, ON/OFF key.
If I use platform_get_resource and devm_ioremap_resource, rtc driver
fail to probe.

best regards
Frank Li


>> +
>> +     if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
>> +             pdata->keycode = KEY_POWER;
>> +             dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
>> +     }
>> +
>> +     pdata->wakeup = !!of_get_property(np, "linux,wakeup", NULL);
>
> Just "wakeup", unlike "keycode" it is not linux-specific property, you
> want wakeup on all OSes (or you don't).
>
>> +
>> +     pdata->irq = platform_get_irq(pdev, 0);
>> +     if (pdata->irq < 0) {
>> +             dev_err(&pdev->dev, "no irq defined in platform data\n");
>> +             return -EINVAL;
>> +     }
>> +
>> +     ioaddr = pdata->ioaddr;
>> +     val = readl_relaxed(ioaddr + SNVS_LPCR_REG);
>> +     val |= SNVS_LPCR_DEP_EN,
>> +     writel_relaxed(val, ioaddr + SNVS_LPCR_REG);
>> +     /* clear the unexpected interrupt before driver ready */
>> +     val = readl_relaxed(ioaddr + SNVS_LPSR_REG);
>> +     if (val & SNVS_LPSR_SPO)
>> +             writel_relaxed(val | SNVS_LPSR_SPO, ioaddr + SNVS_LPSR_REG);
>> +
>> +     setup_timer(&pdata->check_timer,
>> +                 imx_imx_snvs_check_for_events, (unsigned long) pdata);
>> +
>> +     input = devm_input_allocate_device(&pdev->dev);
>> +     if (!input) {
>> +             dev_err(&pdev->dev, "failed to allocate the input device\n");
>> +             return -ENOMEM;
>> +     }
>> +
>> +     input->name = pdev->name;
>> +     input->phys = "snvs-pwrkey/input0";
>> +     input->id.bustype = BUS_HOST;
>> +     input->evbit[0] = BIT_MASK(EV_KEY);
>
> No need to explicitly set EV_KEY bit, in newer kernels
> input_set_capability() does this for you.
>
>> +
>> +     input_set_capability(input, EV_KEY, pdata->keycode);
>> +
>> +     /* input customer action to cancel release timer */
>> +     ret = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
>> +     if (ret) {
>> +             dev_err(&pdev->dev, "failed to register remove action\n");
>> +             return ret;
>> +     }
>> +
>> +     ret = devm_request_irq(&pdev->dev, pdata->irq,
>> +                            imx_snvs_pwrkey_interrupt,
>> +                            0, pdev->name, pdev);
>> +
>> +     if (ret) {
>> +             dev_err(&pdev->dev, "interrupt not available.\n");
>> +             return ret;
>> +     }
>> +
>> +     ret = input_register_device(input);
>> +     if (ret < 0) {
>> +             dev_err(&pdev->dev, "failed to register input device\n");
>> +             input_free_device(input);
>> +             return ret;
>> +     }
>> +
>> +     pdata->input = input;
>> +     platform_set_drvdata(pdev, pdata);
>> +
>> +     device_init_wakeup(&pdev->dev, pdata->wakeup);
>> +
>> +     dev_info(&pdev->dev, "i.MX snvs powerkey probed\n");
>
> Drop this, input core will print message for the device.
>
>> +
>> +     return 0;
>> +}
>> +
>> +static int imx_snvs_pwrkey_remove(struct platform_device *pdev)
>> +{
>> +     struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
>> +
>> +     input_unregister_device(pdata->input);
>
> Not needed with devm-managed input device.
>
>> +     iounmap(pdata->ioaddr);
>
> If you switch to devm_ioremap_resource you can remove
> imx_snvs_pwrkey_remove() altogether.
>
>> +
>> +     return 0;
>> +}
>> +
>> +static int imx_snvs_pwrkey_suspend(struct device *dev)
>> +{
>> +     struct platform_device *pdev = to_platform_device(dev);
>> +     struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
>> +
>> +     if (device_may_wakeup(&pdev->dev))
>> +             enable_irq_wake(pdata->irq);
>> +
>> +     return 0;
>> +}
>> +
>> +static int imx_snvs_pwrkey_resume(struct device *dev)
>> +{
>> +     struct platform_device *pdev = to_platform_device(dev);
>> +     struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
>> +
>> +     if (device_may_wakeup(&pdev->dev))
>> +             disable_irq_wake(pdata->irq);
>> +
>> +     return 0;
>> +}
>> +
>> +static const struct of_device_id imx_snvs_pwrkey_ids[] = {
>> +     { .compatible = "fsl,imx6sx-snvs-pwrkey" },
>> +     { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
>> +
>> +static SIMPLE_DEV_PM_OPS(imx_snvs_pwrkey_pm_ops, imx_snvs_pwrkey_suspend,
>> +                             imx_snvs_pwrkey_resume);
>> +
>> +static struct platform_driver imx_snvs_pwrkey_driver = {
>> +     .driver = {
>> +             .name = "snvs_pwrkey",
>> +             .owner  = THIS_MODULE,
>
> No need to set the owner, we do this automatically.
>
>> +             .pm     = &imx_snvs_pwrkey_pm_ops,
>> +             .of_match_table = imx_snvs_pwrkey_ids,
>> +     },
>> +     .probe = imx_snvs_pwrkey_probe,
>> +     .remove = imx_snvs_pwrkey_remove,
>> +};
>> +module_platform_driver(imx_snvs_pwrkey_driver);
>> +
>> +MODULE_AUTHOR("Freescale Semiconductor");
>> +MODULE_DESCRIPTION("i.MX snvs power key Driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 1.9.1
>>
>
> Thanks.
>
> --
> Dmitry



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