Re: [PATCH v10 2/2] tty/serial: Add Spreadtrum sc9836-uart driver support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




Hi Varka,

On 01/29/2015 10:26 AM, Varka Bhadram wrote:
> Hi,
> 
> On Wednesday 28 January 2015 04:38 PM, Chunyan Zhang wrote:
>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>> spreadtrum sharkl64 platform.
>> This driver also support earlycon.
>>
>> Originally-by: Lanqing Liu <lanqing.liu@xxxxxxxxxxxxxx>
>> Signed-off-by: Orson Zhai <orson.zhai@xxxxxxxxxxxxxx>
>> Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxxxxxx>
>> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
>> Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
>> ---
>>   drivers/tty/serial/Kconfig       |   18 +
>>   drivers/tty/serial/Makefile      |    1 +
>>   drivers/tty/serial/sprd_serial.c |  793 ++++++++++++++++++++++++++++++++++++++
>>   include/uapi/linux/serial_core.h |    3 +
>>   4 files changed, 815 insertions(+)
>>   create mode 100644 drivers/tty/serial/sprd_serial.c
>>
> (...)
> 
>> +static int sprd_probe(struct platform_device *pdev)
>> +{
>> +    struct resource *res;
>> +    struct uart_port *up;
>> +    struct clk *clk;
>> +    int irq;
>> +    int index;
>> +    int ret;
>> +
>> +    for (index = 0; index < ARRAY_SIZE(sprd_port); index++)
>> +        if (sprd_port[index] == NULL)
>> +            break;
>> +
>> +    if (index == ARRAY_SIZE(sprd_port))
>> +        return -EBUSY;
>> +
>> +    index = sprd_probe_dt_alias(index, &pdev->dev);
>> +
>> +    sprd_port[index] = devm_kzalloc(&pdev->dev,
>> +        sizeof(*sprd_port[index]), GFP_KERNEL);
>> +    if (!sprd_port[index])
>> +        return -ENOMEM;
>> +
>> +    up = &sprd_port[index]->port;
>> +    up->dev = &pdev->dev;
>> +    up->line = index;
>> +    up->type = PORT_SPRD;
>> +    up->iotype = SERIAL_IO_PORT;
>> +    up->uartclk = SPRD_DEF_RATE;
>> +    up->fifosize = SPRD_FIFO_SIZE;
>> +    up->ops = &serial_sprd_ops;
>> +    up->flags = UPF_BOOT_AUTOCONF;
>> +
>> +    clk = devm_clk_get(&pdev->dev, NULL);
>> +    if (!IS_ERR(clk))
>> +        up->uartclk = clk_get_rate(clk);
>> +
>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +    if (!res) {
>> +        dev_err(&pdev->dev, "not provide mem resource\n");
>> +        return -ENODEV;
>> +    }
> 
> This check is not required. It will be done by devm_ioremap_resource()

I disagree. devm_ioremap_resource() interprets the NULL resource as
a bad parameter and returns -EINVAL which is then forwarded as the
return value from the probe.

-ENODEV is the correct return value from the probe if the expected
resource is not available (either because it doesn't exist or was already
claimed by another driver).

Regards,
Peter Hurley

>> +    up->mapbase = res->start;
>> +    up->membase = devm_ioremap_resource(&pdev->dev, res);
>> +    if (IS_ERR(up->membase))
>> +        return PTR_ERR(up->membase);
>> +
>>
> 

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux