seria: sirf: only use lookup table to set baudrate when ioclk=150MHz
PATCH 1/1 seria: sirf: only use lookup table to set baudrate when ioclk=150MHz
From: Barry Song <[email protected]>
The fast lookup table to set baudrate is only right when ioclk is 150MHz. for most platforms, ioclk is 150MHz, but some boards might set ioclk to other frequency.
so re-calc the clk_div_reg when ioclk is not 150MHz.
--- drivers/tty/serial/sirfsoc_uart.c | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-)
drivers/tty/serial/sirfsoc_uart.c +13 -5
@@ -375,7 +375,12 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,int threshold_div;int temp; - ioclk_rate =150000000 ; +struct clk *clk =clk_get_sys ("io" ,NULL ); +BUG_ON (IS_ERR (clk)); + + ioclk_rate =clk_get_rate (clk); +clk_put (clk); +switch (termios->c_cflag &CSIZE ) {default :case CS8 :
@@ -431,10 +436,13 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,sirfsoc_uart_disable_ms (port); } -/* common rate: fast calculation */ -for (ic =0 ; ic <SIRF_BAUD_RATE_SUPPORT_NR ; ic++) -if (baud_rate == baudrate_to_regv[ic].baud_rate) - clk_div_reg = baudrate_to_regv[ic].reg_val; +if (ioclk_rate ==150000000 ) { +/* common rate: fast calculation */ +for (ic =0 ; ic <SIRF_BAUD_RATE_SUPPORT_NR ; ic++) +if (baud_rate == baudrate_to_regv[ic].baud_rate) + clk_div_reg = baudrate_to_regv[ic].reg_val; + } + setted_baud = baud_rate;/* arbitary rate setting */ if (unlikely (clk_div_reg ==0 ))
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PATCH 1/1 seria: sirf: only use lookup table to set baudrate when ioclk=150MHz
Hello.
Quoted 18 lines · Barry Song
From: Barry Song <[email protected]>
The fast lookup table to set baudrate is only right when ioclk is 150MHz. for most platforms, ioclk is 150MHz, but some boards might set ioclk to other frequency.
so re-calc the
clk_div_regwhen ioclk is not 150MHz.Signed-off-by Barry Song <[email protected]>--- drivers/tty/serial/sirfsoc_uart.c | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-)drivers/tty/serial/sirfsoc_uart.c +0
-0
drivers/tty/serial/sirfsoc_uart.c static void sirfsoc_uart_set_termios(struct uart_port *port, · line 378
Quoted 5 lines
drivers/tty/serial/sirfsoc_uart.c +1
-1@@ -375,7 +375,12 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,int threshold_div;int temp; - ioclk_rate =150000000 ; +struct clk *clk =clk_get_sys ("io" ,NULL );
Please keep the coding style and insert emoty line here; you can also remove
preceding empty line (not to break the declaration block).
drivers/tty/serial/sirfsoc_uart.c static void sirfsoc_uart_set_termios(struct uart_port *port, · line 386
Quoted 8 lines
drivers/tty/serial/sirfsoc_uart.c +5
-0+BUG_ON (IS_ERR (clk)); + + ioclk_rate =clk_get_rate (clk); +clk_put (clk); +switch (termios->c_cflag &CSIZE ) {default :case CS8 :
WBR, Sergei
PATCH 1/1 seria: sirf: only use lookup table to set baudrate when ioclk=150MHz
In reply to Barry Songdrivers/tty/serial/sirfsoc_uart.c static void sirfsoc_uart_set_termios(struct uart_port *port, · line 379
Quoted 7 lines · Barry Song
drivers/tty/serial/sirfsoc_uart.c +2
-1@@ -375,7 +375,12 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,int threshold_div;int temp; - ioclk_rate =150000000 ; +struct clk *clk =clk_get_sys ("io" ,NULL ); +BUG_ON (IS_ERR (clk));
No. Really, no. Stop using BUG_ON() as some kind of crappy assert(). BUG_ON() takes the entire kernel out when it fails. There's absolutely no need for this what so ever - especially here.
Get the clock at probe or port initialization time. Save that pointer. Only give it up when the port is torn down. And treat it as any other clock - prepare and enable it, and disable and unprepare it when you're done with it.
And there's no need to use this clk_get_sys() crap in drivers. Add the necessary clkdev entries or deal with it in DT. Absolutely do not use clk_get_sys() in drivers; it's there for *PLATFORM* code to use when there's no other possibility for them and NOT drivers.
PATCH 1/1 seria: sirf: only use lookup table to set baudrate when ioclk=150MHz
2012/12/26, Russell King - ARM Linux <[email protected]>:
Quoted 19 lines · Barry Song
drivers/tty/serial/sirfsoc_uart.c static void sirfsoc_uart_set_termios(struct uart_port · line 380
Quoted 8 lines
drivers/tty/serial/sirfsoc_uart.c +2
-1@@ -375,7 +375,12 @@ static void sirfsoc_uart_set_termios(struct uart_port *port, int threshold_div;int temp; - ioclk_rate =150000000 ; +struct clk *clk =clk_get_sys ("io" ,NULL ); +BUG_ON (IS_ERR (clk));No. Really, no. Stop using
BUG_ON()as some kind of crappyassert().BUG_ON()takes the entire kernel out when it fails. There's absolutely no need for this what so ever - especially here.Get the clock at probe or port initialization time. Save that pointer. Only give it up when the port is torn down. And treat it as any other clock - prepare and enable it, and disable and unprepare it when you're done with it.
Quoted 4 lines
And there's no need to use this
clk_get_sys()crap in drivers. Add the necessary clkdev entries or deal with it in DT. Absolutely do not useclk_get_sys()in drivers; it's there for *PLATFORM* code to use when there's no other possibility for them and NOT drivers.
Thanks, Russell.
what made this happen is that clkio is used in io bus and by all of dmac, nand, audio, uart, i2c, spi, usp, pwm, pulse as an input, so we took it as a global/system clock. this way should be not good for the real users.
as i have enabled "clk: prima2: enable dt-binding clkdev mapping"
https://patchwork.kernel.org/patch/1898811/
i might simply let uart node in DT takes the uart clk output of clk controller as your suggestion.
-barry