| Message ID | 1347448523-19565-4-git-send-email-jose.goncalves@inov.pt |
|---|---|
| State | Superseded |
| Delegated to: | Albert ARIBAUD |
| Headers | show |
Dear José Miguel Gonçalves, > Serial driver for the S3C24XX SoCs. > > Signed-off-by: José Miguel Gonçalves <jose.goncalves@inov.pt> > --- > drivers/serial/Makefile | 1 + > drivers/serial/s3c24xx_serial.c | 146 > +++++++++++++++++++++++++++++++++++++++ 2 files changed, 147 insertions(+) > create mode 100644 drivers/serial/s3c24xx_serial.c > > diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile > index 65d0f23..2cbdaac 100644 > --- a/drivers/serial/Makefile > +++ b/drivers/serial/Makefile > @@ -52,6 +52,7 @@ COBJS-$(CONFIG_PL011_SERIAL) += serial_pl01x.o > COBJS-$(CONFIG_PXA_SERIAL) += serial_pxa.o > COBJS-$(CONFIG_SA1100_SERIAL) += serial_sa1100.o > COBJS-$(CONFIG_S3C24X0_SERIAL) += serial_s3c24x0.o > +COBJS-$(CONFIG_S3C24XX_SERIAL) += s3c24xx_serial.o What's the difference between those two drivers ?! > COBJS-$(CONFIG_S3C44B0_SERIAL) += serial_s3c44b0.o > COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o > COBJS-$(CONFIG_SANDBOX_SERIAL) += sandbox.o > diff --git a/drivers/serial/s3c24xx_serial.c > b/drivers/serial/s3c24xx_serial.c new file mode 100644 > index 0000000..11f13a5 > --- /dev/null > +++ b/drivers/serial/s3c24xx_serial.c > @@ -0,0 +1,146 @@ > +/* > + * (C) Copyright 2012 INOV - INESC Inovacao > + * Jose Goncalves <jose.goncalves@inov.pt> > + * > + * Based on drivers/serial/s3c64xx.c > + * > + * See file CREDITS for list of people who contributed to this > + * project. > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License as > + * published by the Free Software Foundation; either version 2 of > + * the License, or (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, > + * MA 02111-1307 USA > + */ > + > +#include <common.h> > +#include <asm/arch/s3c24xx_cpu.h> > + > +DECLARE_GLOBAL_DATA_PTR; > + > +#ifdef CONFIG_SERIAL0 > +#define UART_NR S3C24XX_UART0 > + > +#elif defined(CONFIG_SERIAL1) > +#define UART_NR S3C24XX_UART1 > + > +#elif defined(CONFIG_SERIAL2) > +#define UART_NR S3C24XX_UART2 > + > +#elif defined(CONFIG_SERIAL3) > +#define UART_NR S3C24XX_UART3 > + > +#else > +#error "Bad: you didn't configure serial ..." Error itself is "Bad:" so remove it > +#endif > + > +#define barrier() asm volatile("" ::: "memory") Is that even used ? > +/* > + * The coefficient, used to calculate the baudrate on S3C24XX UARTs is > + * calculated as C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT > + * however, section 2.1.10 of the S3C2416 User's Manual doesn't recommend > + * using 1 for 1, 3 for 2, ... (2^n - 1) for n, instead, they suggest > using + * these constants: > + */ > +static const int udivslot[] = { const int const ... const array const members > + 0x0000, 0x0080, 0x0808, 0x0888, 0x2222, 0x4924, 0x4A52, 0x54AA, > + 0x5555, 0xD555, 0xD5D5, 0xDDD5, 0xDDDD, 0xDFDD, 0xDFDF, 0xFFDF, > +}; > + > +void serial_setbrg(void) > +{ > + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); > + u32 pclk; > + u32 baudrate; > + int i; > + > + pclk = get_PCLK(); > + baudrate = gd->baudrate; > + > + uart->ubrdiv = (pclk / baudrate / 16) - 1; > + uart->udivslot = udivslot[(pclk / baudrate) % 16]; > + > + for (i = 0; i < 100; i++) > + barrier(); > +} > + > +/* > + * Initialise the serial port with the given baudrate. The settings > + * are always 8 data bits, no parity, 1 stop bit, no start bits. > + */ > +int serial_init(void) > +{ > + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); > + > + /* FIFO enable, Tx/Rx FIFO clear */ > + uart->ufcon = 0x07; > + uart->umcon = 0x00; Magic numbers, fix > + /* Normal mode, No parity, 1 stop bit, 8 data bits */ > + uart->ulcon = 0x03; > + /* Polling mode */ > + uart->ucon = 0x005; > + > + serial_setbrg(); > + > + return 0; > +} > + > +/* > + * Read a single byte from the serial port. > + */ > +int serial_getc(void) > +{ > + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); > + > + /* Wait for character to arrive */ > + while (!(uart->utrstat & 0x1)) ; > + > + return uart->urxh & 0xff; > +} > + > +/* > + * Output a single byte to the serial port. > + */ > +void serial_putc(const char c) > +{ > + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); > + > + /* Wait for room in the TX FIFO */ > + while (!(uart->utrstat & 0x2)) ; > + > + uart->utxh = c; > + > + /* If \n, also do \r */ > + if (c == '\n') > + serial_putc('\r'); > +} > + > +/* > + * Test whether a character is in the RX buffer. > + */ > +int serial_tstc(void) > +{ > + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); > + > + return uart->utrstat & 0x1; > +} > + > +/* > + * Output a string to the serial port. > + */ > +void serial_puts(const char *s) > +{ > + while (*s) > + serial_putc(*s++); > +} Can you implement it as a serial multi (CONFIG_SERIAL_MULTI) right away ? thanks. Best regards, Marek Vasut
Hi Marek, On 09/12/2012 10:01 PM, Marek Vasut wrote: > Dear José Miguel Gonçalves, > >> Serial driver for the S3C24XX SoCs. >> >> Signed-off-by: José Miguel Gonçalves <jose.goncalves@inov.pt> >> --- >> drivers/serial/Makefile | 1 + >> drivers/serial/s3c24xx_serial.c | 146 >> +++++++++++++++++++++++++++++++++++++++ 2 files changed, 147 insertions(+) >> create mode 100644 drivers/serial/s3c24xx_serial.c >> >> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile >> index 65d0f23..2cbdaac 100644 >> --- a/drivers/serial/Makefile >> +++ b/drivers/serial/Makefile >> @@ -52,6 +52,7 @@ COBJS-$(CONFIG_PL011_SERIAL) += serial_pl01x.o >> COBJS-$(CONFIG_PXA_SERIAL) += serial_pxa.o >> COBJS-$(CONFIG_SA1100_SERIAL) += serial_sa1100.o >> COBJS-$(CONFIG_S3C24X0_SERIAL) += serial_s3c24x0.o >> +COBJS-$(CONFIG_S3C24XX_SERIAL) += s3c24xx_serial.o > What's the difference between those two drivers ?! No substantial differences exists. The UART controller block is the same in all S3C24XX chips. One difference is the number of UARTs. The more recent chips (S3C2416 & S3C2450) have 4 instead of the 3 found on the old ones. Besides that, the driver that I submitted uses a more precise method for baudrate generation. >> + >> +#ifdef CONFIG_SERIAL0 >> +#define UART_NR S3C24XX_UART0 >> + >> +#elif defined(CONFIG_SERIAL1) >> +#define UART_NR S3C24XX_UART1 >> + >> +#elif defined(CONFIG_SERIAL2) >> +#define UART_NR S3C24XX_UART2 >> + >> +#elif defined(CONFIG_SERIAL3) >> +#define UART_NR S3C24XX_UART3 >> + >> +#else >> +#error "Bad: you didn't configure serial ..." > Error itself is "Bad:" so remove it OK. > >> +#endif >> + >> +#define barrier() asm volatile("" ::: "memory") > Is that even used ? Yes. Without it the GCC optimization removes the loop at the end of the baurate generation routine. >> +/* >> + * The coefficient, used to calculate the baudrate on S3C24XX UARTs is >> + * calculated as C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT >> + * however, section 2.1.10 of the S3C2416 User's Manual doesn't recommend >> + * using 1 for 1, 3 for 2, ... (2^n - 1) for n, instead, they suggest >> using + * these constants: >> + */ >> +static const int udivslot[] = { > const int const ... const array const members It don't see the need for that because you have a constant array when their members are constant and; static const int udivslot[]; static int const udivslot[]; are both (correct) forms to declare an array of constant integers. >> + 0x0000, 0x0080, 0x0808, 0x0888, 0x2222, 0x4924, 0x4A52, 0x54AA, >> + 0x5555, 0xD555, 0xD5D5, 0xDDD5, 0xDDDD, 0xDFDD, 0xDFDF, 0xFFDF, >> +}; >> + >> +void serial_setbrg(void) >> +{ >> + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); >> + u32 pclk; >> + u32 baudrate; >> + int i; >> + >> + pclk = get_PCLK(); >> + baudrate = gd->baudrate; >> + >> + uart->ubrdiv = (pclk / baudrate / 16) - 1; >> + uart->udivslot = udivslot[(pclk / baudrate) % 16]; >> + >> + for (i = 0; i < 100; i++) >> + barrier(); >> +} >> + >> +/* >> + * Initialise the serial port with the given baudrate. The settings >> + * are always 8 data bits, no parity, 1 stop bit, no start bits. >> + */ >> +int serial_init(void) >> +{ >> + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); >> + >> + /* FIFO enable, Tx/Rx FIFO clear */ >> + uart->ufcon = 0x07; >> + uart->umcon = 0x00; > Magic numbers, fix OK. > Can you implement it as a serial multi (CONFIG_SERIAL_MULTI) right away ? > thanks. > I will look at that option and change the driver to support it. Best regards, José Gonçalves
Dear José Miguel Gonçalves, > Hi Marek, > > On 09/12/2012 10:01 PM, Marek Vasut wrote: > > Dear José Miguel Gonçalves, > > > >> Serial driver for the S3C24XX SoCs. > >> > >> Signed-off-by: José Miguel Gonçalves <jose.goncalves@inov.pt> > >> --- > >> > >> drivers/serial/Makefile | 1 + > >> drivers/serial/s3c24xx_serial.c | 146 > >> > >> +++++++++++++++++++++++++++++++++++++++ 2 files changed, 147 > >> insertions(+) > >> > >> create mode 100644 drivers/serial/s3c24xx_serial.c > >> > >> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile > >> index 65d0f23..2cbdaac 100644 > >> --- a/drivers/serial/Makefile > >> +++ b/drivers/serial/Makefile > >> @@ -52,6 +52,7 @@ COBJS-$(CONFIG_PL011_SERIAL) += serial_pl01x.o > >> > >> COBJS-$(CONFIG_PXA_SERIAL) += serial_pxa.o > >> COBJS-$(CONFIG_SA1100_SERIAL) += serial_sa1100.o > >> COBJS-$(CONFIG_S3C24X0_SERIAL) += serial_s3c24x0.o > >> > >> +COBJS-$(CONFIG_S3C24XX_SERIAL) += s3c24xx_serial.o > > > > What's the difference between those two drivers ?! > > No substantial differences exists. The UART controller block is the same > in all S3C24XX chips. One difference is the number of UARTs. The more > recent chips (S3C2416 & S3C2450) have 4 instead of the 3 found on the > old ones. Besides that, the driver that I submitted uses a more precise > method for baudrate generation. So we will have two drivers for the same hardware? No way ... Use the original one and apply incremental patches onto it to improve it. > >> + > >> +#ifdef CONFIG_SERIAL0 > >> +#define UART_NR S3C24XX_UART0 > >> + > >> +#elif defined(CONFIG_SERIAL1) > >> +#define UART_NR S3C24XX_UART1 > >> + > >> +#elif defined(CONFIG_SERIAL2) > >> +#define UART_NR S3C24XX_UART2 > >> + > >> +#elif defined(CONFIG_SERIAL3) > >> +#define UART_NR S3C24XX_UART3 > >> + > >> +#else > >> +#error "Bad: you didn't configure serial ..." > > > > Error itself is "Bad:" so remove it > > OK. > > >> +#endif > >> + > >> +#define barrier() asm volatile("" ::: "memory") > > > > Is that even used ? > > Yes. Without it the GCC optimization removes the loop at the end of the > baurate generation routine. So it's yet another accessor issue. [...] But anyway, there's more. I'd like to teach you how to do things properly. So let's focus on the in-tree driver and fix that one. Incrementally and in small steps. Best regards, Marek Vasut
Hi Marek, On 09/13/2012 10:17 AM, Marek Vasut wrote: > Dear José Miguel Gonçalves, > >> Hi Marek, >> >> On 09/12/2012 10:01 PM, Marek Vasut wrote: >>> Dear José Miguel Gonçalves, >>> >>>> Serial driver for the S3C24XX SoCs. >>>> >>>> Signed-off-by: José Miguel Gonçalves <jose.goncalves@inov.pt> >>>> --- >>>> >>>> drivers/serial/Makefile | 1 + >>>> drivers/serial/s3c24xx_serial.c | 146 >>>> >>>> +++++++++++++++++++++++++++++++++++++++ 2 files changed, 147 >>>> insertions(+) >>>> >>>> create mode 100644 drivers/serial/s3c24xx_serial.c >>>> >>>> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile >>>> index 65d0f23..2cbdaac 100644 >>>> --- a/drivers/serial/Makefile >>>> +++ b/drivers/serial/Makefile >>>> @@ -52,6 +52,7 @@ COBJS-$(CONFIG_PL011_SERIAL) += serial_pl01x.o >>>> >>>> COBJS-$(CONFIG_PXA_SERIAL) += serial_pxa.o >>>> COBJS-$(CONFIG_SA1100_SERIAL) += serial_sa1100.o >>>> COBJS-$(CONFIG_S3C24X0_SERIAL) += serial_s3c24x0.o >>>> >>>> +COBJS-$(CONFIG_S3C24XX_SERIAL) += s3c24xx_serial.o >>> What's the difference between those two drivers ?! >> No substantial differences exists. The UART controller block is the same >> in all S3C24XX chips. One difference is the number of UARTs. The more >> recent chips (S3C2416 & S3C2450) have 4 instead of the 3 found on the >> old ones. Besides that, the driver that I submitted uses a more precise >> method for baudrate generation. > So we will have two drivers for the same hardware? No way ... Use the original > one and apply incremental patches onto it to improve it. > >>>> + >>>> +#ifdef CONFIG_SERIAL0 >>>> +#define UART_NR S3C24XX_UART0 >>>> + >>>> +#elif defined(CONFIG_SERIAL1) >>>> +#define UART_NR S3C24XX_UART1 >>>> + >>>> +#elif defined(CONFIG_SERIAL2) >>>> +#define UART_NR S3C24XX_UART2 >>>> + >>>> +#elif defined(CONFIG_SERIAL3) >>>> +#define UART_NR S3C24XX_UART3 >>>> + >>>> +#else >>>> +#error "Bad: you didn't configure serial ..." >>> Error itself is "Bad:" so remove it >> OK. >> >>>> +#endif >>>> + >>>> +#define barrier() asm volatile("" ::: "memory") >>> Is that even used ? >> Yes. Without it the GCC optimization removes the loop at the end of the >> baurate generation routine. > So it's yet another accessor issue. > [...] > > But anyway, there's more. I'd like to teach you how to do things properly. So > let's focus on the in-tree driver and fix that one. Incrementally and in small > steps. OK, I will figure out the best way to do this. If I have any doubts I'll be back to you... Best regards, José Gonçalves
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 65d0f23..2cbdaac 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -52,6 +52,7 @@ COBJS-$(CONFIG_PL011_SERIAL) += serial_pl01x.o COBJS-$(CONFIG_PXA_SERIAL) += serial_pxa.o COBJS-$(CONFIG_SA1100_SERIAL) += serial_sa1100.o COBJS-$(CONFIG_S3C24X0_SERIAL) += serial_s3c24x0.o +COBJS-$(CONFIG_S3C24XX_SERIAL) += s3c24xx_serial.o COBJS-$(CONFIG_S3C44B0_SERIAL) += serial_s3c44b0.o COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o COBJS-$(CONFIG_SANDBOX_SERIAL) += sandbox.o diff --git a/drivers/serial/s3c24xx_serial.c b/drivers/serial/s3c24xx_serial.c new file mode 100644 index 0000000..11f13a5 --- /dev/null +++ b/drivers/serial/s3c24xx_serial.c @@ -0,0 +1,146 @@ +/* + * (C) Copyright 2012 INOV - INESC Inovacao + * Jose Goncalves <jose.goncalves@inov.pt> + * + * Based on drivers/serial/s3c64xx.c + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/arch/s3c24xx_cpu.h> + +DECLARE_GLOBAL_DATA_PTR; + +#ifdef CONFIG_SERIAL0 +#define UART_NR S3C24XX_UART0 + +#elif defined(CONFIG_SERIAL1) +#define UART_NR S3C24XX_UART1 + +#elif defined(CONFIG_SERIAL2) +#define UART_NR S3C24XX_UART2 + +#elif defined(CONFIG_SERIAL3) +#define UART_NR S3C24XX_UART3 + +#else +#error "Bad: you didn't configure serial ..." +#endif + +#define barrier() asm volatile("" ::: "memory") + +/* + * The coefficient, used to calculate the baudrate on S3C24XX UARTs is + * calculated as C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT + * however, section 2.1.10 of the S3C2416 User's Manual doesn't recommend + * using 1 for 1, 3 for 2, ... (2^n - 1) for n, instead, they suggest using + * these constants: + */ +static const int udivslot[] = { + 0x0000, 0x0080, 0x0808, 0x0888, 0x2222, 0x4924, 0x4A52, 0x54AA, + 0x5555, 0xD555, 0xD5D5, 0xDDD5, 0xDDDD, 0xDFDD, 0xDFDF, 0xFFDF, +}; + +void serial_setbrg(void) +{ + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); + u32 pclk; + u32 baudrate; + int i; + + pclk = get_PCLK(); + baudrate = gd->baudrate; + + uart->ubrdiv = (pclk / baudrate / 16) - 1; + uart->udivslot = udivslot[(pclk / baudrate) % 16]; + + for (i = 0; i < 100; i++) + barrier(); +} + +/* + * Initialise the serial port with the given baudrate. The settings + * are always 8 data bits, no parity, 1 stop bit, no start bits. + */ +int serial_init(void) +{ + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); + + /* FIFO enable, Tx/Rx FIFO clear */ + uart->ufcon = 0x07; + uart->umcon = 0x00; + /* Normal mode, No parity, 1 stop bit, 8 data bits */ + uart->ulcon = 0x03; + /* Polling mode */ + uart->ucon = 0x005; + + serial_setbrg(); + + return 0; +} + +/* + * Read a single byte from the serial port. + */ +int serial_getc(void) +{ + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); + + /* Wait for character to arrive */ + while (!(uart->utrstat & 0x1)) ; + + return uart->urxh & 0xff; +} + +/* + * Output a single byte to the serial port. + */ +void serial_putc(const char c) +{ + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); + + /* Wait for room in the TX FIFO */ + while (!(uart->utrstat & 0x2)) ; + + uart->utxh = c; + + /* If \n, also do \r */ + if (c == '\n') + serial_putc('\r'); +} + +/* + * Test whether a character is in the RX buffer. + */ +int serial_tstc(void) +{ + s3c24xx_uart *const uart = s3c24xx_get_base_uart(UART_NR); + + return uart->utrstat & 0x1; +} + +/* + * Output a string to the serial port. + */ +void serial_puts(const char *s) +{ + while (*s) + serial_putc(*s++); +}
Serial driver for the S3C24XX SoCs. Signed-off-by: José Miguel Gonçalves <jose.goncalves@inov.pt> --- drivers/serial/Makefile | 1 + drivers/serial/s3c24xx_serial.c | 146 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 147 insertions(+) create mode 100644 drivers/serial/s3c24xx_serial.c