lkml.org 
[lkml]   [2016]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH V3 3/4] 8250: 8250_f81504: Add Fintek F81504/508/512 PCIE-to-UART/GPIO UART support
From
Date
Hi Andy,

Andy Shevchenko 於 2016/2/16 下午 05:11 寫道:
> On Tue, 2016-02-16 at 14:55 +0800, Peter Hung wrote:
>> +static u32 baudrate_table[] = { 1500000, 1152000, 921600 };
>> +static u8 clock_table[] = { F81504_CLKSEL_24_MHZ,
>> F81504_CLKSEL_18DOT46_MHZ,
>> + F81504_CLKSEL_14DOT77_MHZ };
>
> I suggest to replace DOT by _.

ok

>> +/* We should do proper H/W transceiver setting before change to
>> RS485 mode */
>> +static int f81504_rs485_config(struct uart_port *port,
>> + struct serial_rs485 *rs485)
>> +{
>> + u8 setting;
>> + u8 *index = (u8 *) port->private_data;
>
> private_data is a type of void *, therefore no need to have an explicit
> casting.

ok


>> +static int f81504_check_baudrate(u32 baud, size_t *idx)
>> +{
>> + size_t index;
>> + u32 quot, rem;
>> +
>> + for (index = 0; index < ARRAY_SIZE(baudrate_table); ++index)
>
> Post-increment is also okay.
>
>> {
>> + /* Clock source must largeer than desire baudrate */
>> + if (baud > baudrate_table[index])
>> + continue;
>> +
>> + quot = DIV_ROUND_CLOSEST(baudrate_table[index],
>> baud);
>
> So, how quot is used and is it possible to set, for example, baud rate
> as 1000000 or 576000?

The IC don't support B1000000 due to no 16MHz clock source.

The quot & rem is only use for compare, and it's must be not 0
when the code run to calculate DIV_ROUND_CLOSEST. So quot
is a redundancy here.

This function will find the suitable clock source for future use.
We'll pass suitable baud rate * 16 to port->uartclk for
serial8250_do_set_termios() to do advance divider operations.

I'll rewrite this section with remove quot and direct check
the "baudrate_table[index] % baud" divisible.


>> + u8 tmp, *offset = (u8 *) port->private_data;
>
> Same for provate_data as above.

ok


>> + /*
>> + * direct use 1.8432MHz when baudrate
>> smaller then or
>> + * equal 115200bps
>
> Check your style of comments in a _whole_ your series.

ok


>> + /*
>> + * If it can't found suitable clock source
>> but had old
>> + * accpetable baudrate, we'll use it
>
> Typo: acceptable.
> Baudrate -> baud rate.

ok

>> + port.port.private_data = data; /* save current idx */
>
> Not sure you need to allocate memory for that at all, or maybe use a
> struct with one member (for now).
>

We just pass the index of PCI configuration space currently. So
I just set a allocated u8 memory to private data. We'll maintain
current method.


>> +static SIMPLE_DEV_PM_OPS(f81504_serial_pm_ops,
>> f81504_serial_suspend,
>> + f81504_serial_resume);
>> +
>> +static struct platform_driver f81504_serial_driver = {
>> + .driver = {
>> + .name = F81504_SERIAL_NAME,
>> + .owner = THIS_MODULE,
>
> You perhaps don't need this. Check the rest of the modules.

ok


>> +config SERIAL_8250_F81504
>> + tristate "Fintek F81504/508/512 16550 PCIE device support"
>> if EXPERT
>> + depends on SERIAL_8250 && MFD_FINTEK_F81504_CORE
>> + default SERIAL_8250
>> + select RATIONAL
>
> It seems RATIONAL API is not used here.
>

This driver hadn't use RATIONAL API. I'll remove it.


Thanks for your advice.
--
With Best Regards,
Peter Hung

\
 
 \ /
  Last update: 2016-02-17 10:41    [W:0.050 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site