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

[Michal Simek <monstr@monstr.eu>]

On 09/14/2012 01:00 PM, Marek Vasut wrote:
> 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@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
>>>
>>> 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)

ok. Isn't there any "next" branch for this purpose?
I believe it can go at least to custodian arm tree.

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