Messages in this thread | | | Subject | Re: [PATCH V3 3/4] 8250: 8250_f81504: Add Fintek F81504/508/512 PCIE-to-UART/GPIO UART support | From | Peter Hung <> | Date | Wed, 17 Feb 2016 17:30:15 +0800 |
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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
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