[U-Boot] [PATCH 1/4 v3] serial: Add Zynq serial driver

Michal Simek
2012-09-14T08:19:32Z

On 09/14/2012 09:45 AM, Marek Vasut wrote:
> Dear Michal Simek,
>
>> The driver is used on Xilinx Zynq platform.
>>
>> Signed-off-by: Michal Simek <monstr@monstr.eu>
>> CC: Joe Hershberger <joe.hershberger@gmail.com>
>> CC: Marek Vasut <marex@denx.de>
>>
>> ---
>> v2: Use Zynq name instead of Dragonfire and XPSS/XDFUART
>> Rename driver name
>> Remove driver description
>>
>> v3: SERIAL_MULTI support
>> Rename xdfuart to uart_zynq
>> ---
>> common/serial.c | 8 ++
>> drivers/serial/Makefile | 1 +
>> drivers/serial/serial_zynq.c | 246
>> ++++++++++++++++++++++++++++++++++++++++++ include/serial.h |
>> 5 +
>> 4 files changed, 260 insertions(+), 0 deletions(-)
>> create mode 100644 drivers/serial/serial_zynq.c
>>
>> diff --git a/common/serial.c b/common/serial.c
>> index 75cc1bb..4f2bc7f 100644
>> --- a/common/serial.c
>> +++ b/common/serial.c
>> @@ -122,6 +122,14 @@ void serial_initialize(void)
>> serial_register(&uartlite_serial3_device);
>> # endif /* XILINX_UARTLITE_BASEADDR3 */
>> #endif /* CONFIG_XILINX_UARTLITE */
>> +#if defined(CONFIG_ZYNQ_SERIAL)
>> +# ifdef CONFIG_ZYNQ_SERIAL_BASEADDR0
>> + serial_register(&uart_zynq_serial0_device);
>> +# endif
>> +# ifdef CONFIG_ZYNQ_SERIAL_BASEADDR1
>> + serial_register(&uart_zynq_serial1_device);
>> +# endif
>> +#endif
>> serial_assign(default_serial_console()->name);
>> }
>>
>> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
>> index 65d0f23..dfc22a4 100644
>> --- a/drivers/serial/Makefile
>> +++ b/drivers/serial/Makefile
>> @@ -56,6 +56,7 @@ COBJS-$(CONFIG_S3C44B0_SERIAL) += serial_s3c44b0.o
>> COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o
>> COBJS-$(CONFIG_SANDBOX_SERIAL) += sandbox.o
>> COBJS-$(CONFIG_SCIF_CONSOLE) += serial_sh.o
>> +COBJS-$(CONFIG_ZYNQ_SERIAL) += serial_zynq.o
>>
>> ifndef CONFIG_SPL_BUILD
>> COBJS-$(CONFIG_USB_TTY) += usbtty.o
>> diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c
>> new file mode 100644
>> index 0000000..30f2445
>> --- /dev/null
>> +++ b/drivers/serial/serial_zynq.c
>> @@ -0,0 +1,246 @@
>> +/*
>> + * Copyright (C) 2012 Michal Simek <monstr@monstr.eu>
>> + * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
>> + *
>> + * 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 <watchdog.h>
>> +#include <asm/io.h>
>> +#include <linux/compiler.h>
>> +#include <serial.h>
>> +
>> +#define ZYNQ_UART_SR_TXFULL 0x00000010 /* TX FIFO full */
>> +#define ZYNQ_UART_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
>> +
>> +#define ZYNQ_UART_CR_TX_EN 0x00000010 /* TX enabled */
>> +#define ZYNQ_UART_CR_RX_EN 0x00000004 /* RX enabled */
>> +#define ZYNQ_UART_CR_TXRST 0x00000002 /* TX logic reset */
>> +#define ZYNQ_UART_CR_RXRST 0x00000001 /* RX logic reset */
>> +
>> +#define ZYNQ_UART_MR_PARITY_NONE 0x00000020 /* No parity mode */
>> +
>> +/* Some clock/baud constants */
>> +#define ZYNQ_UART_BDIV 15 /* Default/reset BDIV value */
>> +#define ZYNQ_UART_BASECLK 3125000L /* master / (bdiv + 1) */
>> +
>> +struct uart_zynq {
>> + u32 control; /* Control Register [8:0] */
>> + u32 mode; /* Mode Register [10:0] */
>> + u32 reserved1[4];
>> + u32 baud_rate_gen; /* Baud Rate Generator [15:0] */
>> + u32 reserved2[4];
>> + u32 channel_sts; /* Channel Status [11:0] */
>> + u32 tx_rx_fifo; /* FIFO [15:0] or [7:0] */
>> + u32 baud_rate_divider; /* Baud Rate Divider [7:0] */
>> +};
>> +
>> +static struct uart_zynq *uart_zynq_ports[2] = {
>> +#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR0
>> + [0] = (struct uart_zynq *)CONFIG_ZYNQ_SERIAL_BASEADDR0,
>> +#endif
>> +#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR1
>> + [1] = (struct uart_zynq *)CONFIG_ZYNQ_SERIAL_BASEADDR1,
>> +#endif
>> +};
>> +
>> +struct uart_zynq_params {
>> + u32 baudrate;
>> + u32 clock;
>> +};
>> +
>> +static struct uart_zynq_params uart_zynq_ports_param[2] = {
>> +#if defined(CONFIG_ZYNQ_SERIAL_BAUDRATE0) &&
>> defined(CONFIG_ZYNQ_SERIAL_CLOCK0) + [0].baudrate =
>> CONFIG_ZYNQ_SERIAL_BAUDRATE0,
>> + [0].clock = CONFIG_ZYNQ_SERIAL_CLOCK0,
>> +#endif
>> +#if defined(CONFIG_ZYNQ_SERIAL_BAUDRATE1) &&
>> defined(CONFIG_ZYNQ_SERIAL_CLOCK1) + [1].baudrate =
>> CONFIG_ZYNQ_SERIAL_BAUDRATE1,
>> + [1].clock = CONFIG_ZYNQ_SERIAL_CLOCK1,
>> +#endif
>> +};
>> +
>> +/* Set up the baud rate in gd struct */
>> +static void uart_zynq_serial_setbrg(const int port)
>> +{
>> + /* Calculation results. */
>> + unsigned int calc_bauderror, bdiv, bgen;
>> + unsigned long calc_baud = 0;
>> + unsigned long baud = uart_zynq_ports_param[port].baudrate;
>> + unsigned long clock = uart_zynq_ports_param[port].clock;
>> + struct uart_zynq *regs = uart_zynq_ports[port];
>> +
>> + /* master clock
>> + * Baud rate = ------------------
>> + * bgen * (bdiv + 1)
>> + *
>> + * Find acceptable values for baud generation.
>> + */
>> + for (bdiv = 4; bdiv < 255; bdiv++) {
>> + bgen = clock / (baud * (bdiv + 1));
>> + if (bgen < 2 || bgen > 65535)
>> + continue;
>> +
>> + calc_baud = clock / (bgen * (bdiv + 1));
>> +
>> + /*
>> + * Use first calculated baudrate with
>> + * an acceptable (<3%) error
>> + */
>> + if (baud > calc_baud)
>> + calc_bauderror = baud - calc_baud;
>> + else
>> + calc_bauderror = calc_baud - baud;
>> + if (((calc_bauderror * 100) / baud) < 3)
>> + break;
>> + }
>> +
>> + writel(bdiv, &regs->baud_rate_divider);
>> + writel(bgen, &regs->baud_rate_gen);
>> +}
>> +
>> +/* Initialize the UART, with...some settings. */
>> +static int uart_zynq_serial_init(const int port)
>> +{
>> + struct uart_zynq *regs = uart_zynq_ports[port];
>> +
>> + if (!regs)
>> + return -1;
>> +
>> + /* RX/TX enabled & reset */
>> + writel(ZYNQ_UART_CR_TX_EN | ZYNQ_UART_CR_RX_EN | ZYNQ_UART_CR_TXRST | \
>> + ZYNQ_UART_CR_RXRST, &regs->control);
>> + writel(ZYNQ_UART_MR_PARITY_NONE, &regs->mode); /* 8 bit, no parity */
>> + uart_zynq_serial_setbrg(port);
>> +
>> + return 0;
>> +}
>> +
>> +static void uart_zynq_serial_putc(const char c, const int port)
>> +{
>> + struct uart_zynq *regs = uart_zynq_ports[port];
>> +
>> + while ((readl(&regs->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0)
>> + WATCHDOG_RESET();
>> +
>> + if (c == '\n') {
>> + writel('\r', &regs->tx_rx_fifo);
>> + while ((readl(&regs->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0)
>> + WATCHDOG_RESET();
>> + }
>> + writel(c, &regs->tx_rx_fifo);
>> +}
>> +
>> +static void uart_zynq_serial_puts(const char *s, const int port)
>> +{
>> + while (*s)
>> + uart_zynq_serial_putc(*s++, port);
>> +}
>
> Remark for myself ... squash all these while (*s) putc() constructs into serial
> core. I'll be adding a patch into my massive patchset I'm cooking for this, you
> don't worry as this is ok for now.
>
>> +static int uart_zynq_serial_tstc(const int port)
>> +{
>> + struct uart_zynq *regs = uart_zynq_ports[port];
>> +
>> + return (readl(&regs->channel_sts) & ZYNQ_UART_SR_RXEMPTY) == 0;
>> +}
>> +
>> +static int uart_zynq_serial_getc(const int port)
>> +{
>> + struct uart_zynq *regs = uart_zynq_ports[port];
>> +
>> + while (!uart_zynq_serial_tstc(port))
>> + WATCHDOG_RESET();
>> + return readl(&regs->tx_rx_fifo);
>> +}
>> +
>> +#if !defined(CONFIG_SERIAL_MULTI)
>> +int serial_init(void)
>> +{
>> + return uart_zynq_serial_init(0);
>> +}
>> +
>> +void serial_setbrg(void)
>> +{
>> + uart_zynq_serial_setbrg(0);
>> +}
>> +
>> +void serial_putc(const char c)
>> +{
>> + uart_zynq_serial_putc(c, 0);
>> +}
>> +
>> +void serial_puts(const char *s)
>> +{
>> + uart_zynq_serial_puts(s, 0);
>> +}
>> +
>> +int serial_getc(void)
>> +{
>> + return uart_zynq_serial_getc(0);
>> +}
>> +
>> +int serial_tstc(void)
>> +{
>> + return uart_zynq_serial_tstc(0);
>> +}
>> +#else
>> +/* Multi serial device functions */
>> +#define DECLARE_PSSERIAL_FUNCTIONS(port) \
>> + int uart_zynq##port##_init(void) \
>> + { return uart_zynq_serial_init(port); } \
>> + void uart_zynq##port##_setbrg(void) \
>> + { return uart_zynq_serial_setbrg(port); } \
>> + int uart_zynq##port##_getc(void) \
>> + { return uart_zynq_serial_getc(port); } \
>> + int uart_zynq##port##_tstc(void) \
>> + { return uart_zynq_serial_tstc(port); } \
>> + void uart_zynq##port##_putc(const char c) \
>> + { uart_zynq_serial_putc(c, port); } \
>> + void uart_zynq##port##_puts(const char *s) \
>> + { uart_zynq_serial_puts(s, port); }
>> +
>> +/* Serial device descriptor */
>> +#define INIT_PSSERIAL_STRUCTURE(port, name) {\
>
> Rename the "name" to __name (this is because once you rename it -- see below --
> name will colide with .name)
>
>> + name,\
>
> explicitly spell out the name of structure members, so the structure instance is
> agile to reordering the the declaration members.

No problem to change it. I have seen it in your stdio branch

>
>> + uart_zynq##port##_init,\
>> + NULL,\
>> + uart_zynq##port##_setbrg,\
>> + uart_zynq##port##_getc,\
>> + uart_zynq##port##_tstc,\
>> + uart_zynq##port##_putc,\
>> + uart_zynq##port##_puts, }
>> +
>> +DECLARE_PSSERIAL_FUNCTIONS(0);
>> +struct serial_device uart_zynq_serial0_device =
>> + INIT_PSSERIAL_STRUCTURE(0, "ttyPS0");
>> +DECLARE_PSSERIAL_FUNCTIONS(1);
>> +struct serial_device uart_zynq_serial1_device =
>> + INIT_PSSERIAL_STRUCTURE(1, "ttyPS1");
>> +
>> +__weak struct serial_device *default_serial_console(void)
>> +{
>> + if (uart_zynq_ports[0])
>> + return &uart_zynq_serial0_device;
>> + if (uart_zynq_ports[1])
>> + return &uart_zynq_serial1_device;
>> +
>> + return NULL;
>> +}
>> +#endif
>> diff --git a/include/serial.h b/include/serial.h
>> index cbdf8a9..dc8e9b4 100644
>> --- a/include/serial.h
>> +++ b/include/serial.h
>> @@ -89,6 +89,11 @@ extern struct serial_device bfin_serial2_device;
>> extern struct serial_device bfin_serial3_device;
>> #endif
>>
>> +#if defined(CONFIG_ZYNQ_SERIAL)
>> +extern struct serial_device uart_zynq_serial0_device;
>> +extern struct serial_device uart_zynq_serial1_device;
>> +#endif
>> +
>
> Let's not add this, noone uses it.

It is used by serial core where you register serial device.
>> + serial_register(&uart_zynq_serial0_device);

You need declaration somewhere. If you don't have it then this error message is shown.
serial.c: In function 'serial_initialize':
serial.c:127:19: error: 'uart_zynq_serial0_device' undeclared (first use in this function)
serial.c:127:19: note: each undeclared identifier is reported only once for each function it appears in

Thanks,
Michal

--
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian