[U-Boot] [PATCH v2 3/3] watchdog: Convert Xilinx Axi watchdog driver to driver model

Michal Simek michal.simek at xilinx.com
Thu Jul 19 07:06:58 UTC 2018


Hi Simon,

On 19.7.2018 03:31, Simon Glass wrote:
> Hi Shreenidhi,
> 
> On 14 July 2018 at 14:35, Shreenidhi Shedi <yesshedi at gmail.com> wrote:
>> Xilinx Axi wdt driver conversion to driver model & Kconfig update
>> for the same.
>>
>> Changes in V1:
>>  - Xilinx Axi wdt driver conversion to DM initial version
>>
>> Changes in V2:
>>  - Rectified print message
>>  - Removed  stop instruction from probe
>>
>> Signed-off-by: Shreenidhi Shedi <yesshedi at gmail.com>
>> ---
>>
>> Changes in v2: None
>>
>>  drivers/watchdog/Kconfig         |   8 +++
>>  drivers/watchdog/xilinx_tb_wdt.c | 105 ++++++++++++++++++++++++-------
>>  2 files changed, 89 insertions(+), 24 deletions(-)
>>
>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>> index 148c6a0d68..351d2af8d9 100644
>> --- a/drivers/watchdog/Kconfig
>> +++ b/drivers/watchdog/Kconfig
>> @@ -103,4 +103,12 @@ config WDT_CDNS
>>            Select this to enable Cadence watchdog timer, which can be found on some
>>            Xilinx Microzed Platform.
>>
>> +config XILINX_TB_WATCHDOG
>> +       bool "Xilinx Axi watchdog timer support"
>> +       depends on WDT
>> +       imply WATCHDOG
>> +       help
>> +          Select this to enable Xilinx Axi watchdog timer, which can be found on some
>> +          Xilinx Microblaze Platform.
> 
> platforms?

will fix.

> 
>> +
>>  endmenu
>> diff --git a/drivers/watchdog/xilinx_tb_wdt.c b/drivers/watchdog/xilinx_tb_wdt.c
>> index 2274123e49..23ddbdfbee 100644
>> --- a/drivers/watchdog/xilinx_tb_wdt.c
>> +++ b/drivers/watchdog/xilinx_tb_wdt.c
>> @@ -1,13 +1,17 @@
>>  // SPDX-License-Identifier: GPL-2.0+
>>  /*
>> + * Xilinx Axi platforms watchdog timer driver.
>> + *
>> + * Author(s):  Michal Šimek <michal.simek at xilinx.com>
>> + *             Shreenidhi Shedi <yesshedi at gmail.com>
>> + *
>>   * Copyright (c) 2011-2013 Xilinx Inc.
>>   */
>>
>>  #include <common.h>
>> -#include <asm/io.h>
>> -#include <asm/microblaze_intc.h>
>> -#include <asm/processor.h>
>> -#include <watchdog.h>
>> +#include <dm.h>
>> +#include <wdt.h>
>> +#include <linux/io.h>
>>
>>  #define XWT_CSR0_WRS_MASK      0x00000008 /* Reset status Mask */
>>  #define XWT_CSR0_WDS_MASK      0x00000004 /* Timer state Mask */
>> @@ -20,49 +24,102 @@ struct watchdog_regs {
>>         u32 tbr; /* 0x8 */
>>  };
>>
>> -static struct watchdog_regs *watchdog_base =
>> -                       (struct watchdog_regs *)CONFIG_WATCHDOG_BASEADDR;
>> +struct xlnx_wdt_priv {
>> +       bool enable_once;
>> +       struct watchdog_regs *regs;
>> +};
>>
>> -void hw_watchdog_reset(void)
>> +static int xlnx_wdt_reset(struct udevice *dev)
> 
> You could pass just regs to this function? Same below.

I don't think so. This function is the part of struct wdt_ops{}
which is

 82         /*
 83          * Reset the timer, typically restoring the counter to
 84          * the value configured by start()
 85          *
 86          * @dev: WDT Device
 87          * @return: 0 if OK, -ve on error
 88          */
 89         int (*reset)(struct udevice *dev);




> 
>>  {
>>         u32 reg;
>> +       struct xlnx_wdt_priv *priv = dev_get_priv(dev);
>> +
>> +       debug("%s\n", __func__);
>>
>>         /* Read the current contents of TCSR0 */
>> -       reg = readl(&watchdog_base->twcsr0);
>> +       reg = readl(&priv->regs->twcsr0);
>>
>>         /* Clear the watchdog WDS bit */
>>         if (reg & (XWT_CSR0_EWDT1_MASK | XWT_CSRX_EWDT2_MASK))
>> -               writel(reg | XWT_CSR0_WDS_MASK, &watchdog_base->twcsr0);
>> +               writel(reg | XWT_CSR0_WDS_MASK, &priv->regs->twcsr0);
>> +
>> +       return 0;
>>  }
>>
>> -void hw_watchdog_disable(void)
>> +static int xlnx_wdt_stop(struct udevice *dev)
>>  {
>>         u32 reg;
>> +       struct xlnx_wdt_priv *priv = dev_get_priv(dev);
>> +
>> +       if (priv->enable_once) {
>> +               puts("Can't stop Xilinx watchdog.\n");
> 
> debug()

will fix

> 
>> +               return -1;
> 
> return -EBUSY
> 
> -1 is -EPERM which might not be correct.

will fix

> 
>> +       }
>>
>>         /* Read the current contents of TCSR0 */
>> -       reg = readl(&watchdog_base->twcsr0);
>> +       reg = readl(&priv->regs->twcsr0);
>>
>> -       writel(reg & ~XWT_CSR0_EWDT1_MASK, &watchdog_base->twcsr0);
>> -       writel(~XWT_CSRX_EWDT2_MASK, &watchdog_base->twcsr1);
>> +       writel(reg & ~XWT_CSR0_EWDT1_MASK, &priv->regs->twcsr0);
>> +       writel(~XWT_CSRX_EWDT2_MASK, &priv->regs->twcsr1);
>>
>>         puts("Watchdog disabled!\n");
> 
> Drivers should not output to the console.

debug is fine here.

> 
>> +
>> +       return 0;
>>  }
>>
>> -static void hw_watchdog_isr(void *arg)
>> +static int xlnx_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
>>  {
>> -       hw_watchdog_reset();
>> +       struct xlnx_wdt_priv *priv = dev_get_priv(dev);
>> +
>> +       writel((XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK | XWT_CSR0_EWDT1_MASK),
>> +              &priv->regs->twcsr0);
>> +
>> +       writel(XWT_CSRX_EWDT2_MASK, &priv->regs->twcsr1);
>> +
>> +       return 0;
>>  }
>>
>> -void hw_watchdog_init(void)
>> +static int xlnx_wdt_probe(struct udevice *dev)
>>  {
>> -       int ret;
>> +       debug("%s: Probing wdt%u\n", __func__, dev->seq);
>>
>> -       writel((XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK | XWT_CSR0_EWDT1_MASK),
>> -              &watchdog_base->twcsr0);
>> -       writel(XWT_CSRX_EWDT2_MASK, &watchdog_base->twcsr1);
>> +       return 0;
>> +}
>>
>> -       ret = install_interrupt_handler(CONFIG_WATCHDOG_IRQ,
>> -                                               hw_watchdog_isr, NULL);
>> -       if (ret)
>> -               puts("Watchdog IRQ registration failed.");
>> +static int xlnx_wdt_ofdata_to_platdata(struct udevice *dev)
>> +{
>> +       struct xlnx_wdt_priv *priv = dev_get_priv(dev);
>> +
>> +       priv->regs = (struct watchdog_regs *)dev_read_addr(dev);
>> +       if (IS_ERR(priv->regs))
>> +               return PTR_ERR(priv->regs);
>> +
>> +       priv->enable_once = dev_read_u32_default(dev, "xlnx,wdt-enable-once",
>> +                                                0);
> 
> Should that not be dev_read_bool()? Does it actually using an integer
> to indicate a boolean? Is there a binding file for this?

Unfortunately no. It is pretty old binding and it wasn't defined as
bool. Here is binding doc.

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt

> 
>> +
>> +       debug("%s: wdt-enable-once %d\n", __func__, priv->enable_once);
>> +
>> +       return 0;
>>  }
>> +
>> +static const struct wdt_ops xlnx_wdt_ops = {
>> +       .start = xlnx_wdt_start,
>> +       .reset = xlnx_wdt_reset,
>> +       .stop = xlnx_wdt_stop,
>> +};
>> +
>> +static const struct udevice_id xlnx_wdt_ids[] = {
>> +       { .compatible = "xlnx,xps-timebase-wdt-1.00.a", },
>> +       { .compatible = "xlnx,xps-timebase-wdt-1.01.a", },
>> +       {},
>> +};
>> +
>> +U_BOOT_DRIVER(xlnx_wdt) = {
>> +       .name = "xlnx_wdt",
>> +       .id = UCLASS_WDT,
>> +       .of_match = xlnx_wdt_ids,
>> +       .probe = xlnx_wdt_probe,
>> +       .priv_auto_alloc_size = sizeof(struct xlnx_wdt_priv),
>> +       .ofdata_to_platdata = xlnx_wdt_ofdata_to_platdata,
>> +       .ops = &xlnx_wdt_ops,
>> +};
>> --
>> 2.17.1
>>

Thanks,
Michal



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