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

Michal Simek
2012-08-14T11:42:44Z

The driver is used on Xilinx Zynq platform.

Signed-off-by: Michal Simek <monstr@monstr.eu>
---
drivers/serial/Makefile | 1 +
drivers/serial/serial_xpssuart.c | 218 ++++++++++++++++++++++++++++++++++++++
2 files changed, 219 insertions(+), 0 deletions(-)
create mode 100644 drivers/serial/serial_xpssuart.c

diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 65d0f23..81350d0 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_XPSS_SERIAL) += serial_xpssuart.o

ifndef CONFIG_SPL_BUILD
COBJS-$(CONFIG_USB_TTY) += usbtty.o
diff --git a/drivers/serial/serial_xpssuart.c b/drivers/serial/serial_xpssuart.c
new file mode 100644
index 0000000..3c6d838
--- /dev/null
+++ b/drivers/serial/serial_xpssuart.c
@@ -0,0 +1,218 @@
+/*
+ * U-Boot driver for Xilinx Dragonfire UART.
+ *
+ * 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 <serial.h>
+
+#define XDFUART_SR_TXFULL 0x00000010 /* TX FIFO full */
+#define XDFUART_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
+
+#define XDFUART_CR_TX_EN 0x00000010 /* TX enabled */
+#define XDFUART_CR_RX_EN 0x00000004 /* RX enabled */
+#define XDFUART_CR_TXRST 0x00000002 /* TX logic reset */
+#define XDFUART_CR_RXRST 0x00000001 /* RX logic reset */
+
+#define XDFUART_MR_PARITY_NONE 0x00000020 /* No parity mode */
+
+/* Some clock/baud constants */
+#define XDFUART_BDIV 15 /* Default/reset BDIV value */
+#define XDFUART_BASECLK 3125000L /* master / (bdiv + 1) */
+
+struct xdfuart {
+ 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 xdfuart *xdf_ports[4] = {
+#ifdef CONFIG_XPSS_SERIAL_BASEADDR0
+ [0] = (struct xdfuart *)CONFIG_XPSS_SERIAL_BASEADDR0,
+#endif
+#ifdef CONFIG_XPSS_SERIAL_BASEADDR1
+ [1] = (struct xdfuart *)CONFIG_XPSS_SERIAL_BASEADDR1,
+#endif
+#ifdef CONFIG_XPSS_SERIAL_BASEADDR2
+ [2] = (struct xdfuart *)CONFIG_XPSS_SERIAL_BASEADDR2,
+#endif
+#ifdef CONFIG_XPSS_SERIAL_BASEADDR3
+ [3] = (struct xdfuart *)CONFIG_XPSS_SERIAL_BASEADDR3,
+#endif
+};
+
+struct xdfuart_params {
+ u32 baudrate;
+ u32 clock;
+};
+
+static struct xdfuart_params xdf_ports_param[4] = {
+#if defined(CONFIG_XPSS_SERIAL_BAUDRATE0) && defined(CONFIG_XPSS_SERIAL_CLOCK0)
+ [0].baudrate = CONFIG_XPSS_SERIAL_BAUDRATE0,
+ [0].clock = CONFIG_XPSS_SERIAL_CLOCK0,
+#endif
+#if defined(CONFIG_XPSS_SERIAL_BAUDRATE1) && defined(CONFIG_XPSS_SERIAL_CLOCK1)
+ [1].baudrate = CONFIG_XPSS_SERIAL_BAUDRATE1,
+ [1].clock = CONFIG_XPSS_SERIAL_CLOCK1,
+#endif
+#if defined(CONFIG_XPSS_SERIAL_BAUDRATE2) && defined(CONFIG_XPSS_SERIAL_CLOCK2)
+ [2].baudrate = CONFIG_XPSS_SERIAL_BAUDRATE2,
+ [2].clock = CONFIG_XPSS_SERIAL_CLOCK2,
+#endif
+#if defined(CONFIG_XPSS_SERIAL_BAUDRATE3) && defined(CONFIG_XPSS_SERIAL_CLOCK3)
+ [3].baudrate = CONFIG_XPSS_SERIAL_BAUDRATE3,
+ [3].clock = CONFIG_XPSS_SERIAL_CLOCK3,
+#endif
+};
+
+/* Set up the baud rate in gd struct */
+static void xdfuart_serial_setbrg(const int port)
+{
+ /* Calculation results. */
+ unsigned int calc_bauderror, bdiv, bgen;
+ unsigned long calc_baud = 0;
+ unsigned long baud = xdf_ports_param[port].baudrate;
+ unsigned long clock = xdf_ports_param[port].clock;
+ struct xdfuart *regs = xdf_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 xdfuart_serial_init(const int port)
+{
+ struct xdfuart *regs = xdf_ports[port];
+
+ if (!regs)
+ return -1;
+
+ /* RX/TX enabled & reset */
+ writel(XDFUART_CR_TX_EN | XDFUART_CR_RX_EN | XDFUART_CR_TXRST | \
+ XDFUART_CR_RXRST, &regs->control);
+ writel(XDFUART_MR_PARITY_NONE, &regs->mode); /* 8 bit, no parity */
+ xdfuart_serial_setbrg(port);
+
+ return 0;
+}
+
+static void xdfuart_serial_putc(const char c, const int port)
+{
+ struct xdfuart *regs = xdf_ports[port];
+
+ while ((readl(&regs->channel_sts) & XDFUART_SR_TXFULL) != 0)
+ WATCHDOG_RESET();
+
+ if (c == '\n') {
+ writel('\r', &regs->tx_rx_fifo);
+ while ((readl(&regs->channel_sts) & XDFUART_SR_TXFULL) != 0)
+ WATCHDOG_RESET();
+ }
+ writel(c, &regs->tx_rx_fifo);
+}
+
+static void xdfuart_serial_puts(const char *s, const int port)
+{
+ while (*s)
+ xdfuart_serial_putc(*s++, port);
+}
+
+static int xdfuart_serial_tstc(const int port)
+{
+ struct xdfuart *regs = xdf_ports[port];
+
+ return (readl(&regs->channel_sts) & XDFUART_SR_RXEMPTY) == 0;
+}
+
+static int xdfuart_serial_getc(const int port)
+{
+ struct xdfuart *regs = xdf_ports[port];
+
+ while (!xdfuart_serial_tstc(port))
+ WATCHDOG_RESET();
+ return readl(&regs->tx_rx_fifo);
+}
+
+#if !defined(CONFIG_SERIAL_MULTI)
+int serial_init(void)
+{
+ return xdfuart_serial_init(0);
+}
+
+void serial_setbrg(void)
+{
+ xdfuart_serial_setbrg(0);
+}
+
+void serial_putc(const char c)
+{
+ xdfuart_serial_putc(c, 0);
+}
+
+void serial_puts(const char *s)
+{
+ xdfuart_serial_puts(s, 0);
+}
+
+int serial_getc(void)
+{
+ return xdfuart_serial_getc(0);
+}
+
+int serial_tstc(void)
+{
+ return xdfuart_serial_tstc(0);
+}
+#endif
--
1.7.0.4