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

Marek Vasut marex at denx.de
Fri Sep 14 13:00:05 CEST 2012 

Dear Michal Simek,

> On 09/14/2012 12:03 PM, Marek Vasut wrote:
> > Dear Michal Simek,
> > 
> >> 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 at monstr.eu>
> >>>> CC: Joe Hershberger <joe.hershberger at gmail.com>
> >>>> CC: Marek Vasut <marex at 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 at 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
> > 
> > Oh damn, you're right ... I reworked the serial core so it's not needed
> > -- by sticking an init func into each and every driver.
> > 
> > Maybe we should start pushing the serial drivers through that branch of
> > mine once I post it?
> 
> You have mentioned in one email that your tree is not ready.
> http://lists.denx.de/pipermail/u-boot/2012-September/133836.html

That's the "once I post it" part of the previous sentence ;-)

> 
> I will send update v4.
> 
> > I guess this platform won't make it into .10 release anyway.
> 
> Why not? Any reason why these 4 patches should wait till the next release?

MW is closed (Aug. 18)

> Even if merge open is still open?
> They are also completely separated from others and they are not breaking
> anything.
> 
> Thanks,
> Michal

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