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authorAlbert ARIBAUD <albert.u.boot@aribaud.net>2013-06-08 14:35:10 +0200
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2013-06-08 14:35:10 +0200
commit10e167329b029890a4c704f094822da5f259b886 (patch)
treec0950b7cb928ee26b07c39348e4539602ce3aec9 /drivers/serial/serial_lpuart.c
parentdbc000bfb51eb30d786521e6b8e29048c36cbefa (diff)
parent4a1c7b13ae104d4526d3176793b7f6b06694df15 (diff)
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Merge branch 'u-boot-imx/master' into 'u-boot-arm/master'
Conflicts: drivers/serial/Makefile
Diffstat (limited to 'drivers/serial/serial_lpuart.c')
-rw-r--r--drivers/serial/serial_lpuart.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/serial/serial_lpuart.c b/drivers/serial/serial_lpuart.c
new file mode 100644
index 0000000..51d5666
--- /dev/null
+++ b/drivers/serial/serial_lpuart.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * 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>
+#include <linux/compiler.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/clock.h>
+
+#define US1_TDRE (1 << 7)
+#define US1_RDRF (1 << 5)
+#define UC2_TE (1 << 3)
+#define UC2_RE (1 << 2)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct lpuart_fsl *base = (struct lpuart_fsl *)LPUART_BASE;
+
+static void lpuart_serial_setbrg(void)
+{
+ u32 clk = mxc_get_clock(MXC_UART_CLK);
+ u16 sbr;
+
+ if (!gd->baudrate)
+ gd->baudrate = CONFIG_BAUDRATE;
+
+ sbr = (u16)(clk / (16 * gd->baudrate));
+ /* place adjustment later - n/32 BRFA */
+
+ __raw_writeb(sbr >> 8, &base->ubdh);
+ __raw_writeb(sbr & 0xff, &base->ubdl);
+}
+
+static int lpuart_serial_getc(void)
+{
+ u8 status;
+
+ while (!(__raw_readb(&base->us1) & US1_RDRF))
+ WATCHDOG_RESET();
+
+ status = __raw_readb(&base->us1);
+ status |= US1_RDRF;
+ __raw_writeb(status, &base->us1);
+
+ return __raw_readb(&base->ud);
+}
+
+static void lpuart_serial_putc(const char c)
+{
+ if (c == '\n')
+ serial_putc('\r');
+
+ while (!(__raw_readb(&base->us1) & US1_TDRE))
+ WATCHDOG_RESET();
+
+ __raw_writeb(c, &base->ud);
+}
+
+/*
+ * Test whether a character is in the RX buffer
+ */
+static int lpuart_serial_tstc(void)
+{
+ if (__raw_readb(&base->urcfifo) == 0)
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Initialise the serial port with the given baudrate. The settings
+ * are always 8 data bits, no parity, 1 stop bit, no start bits.
+ */
+static int lpuart_serial_init(void)
+{
+ u8 ctrl;
+
+ ctrl = __raw_readb(&base->uc2);
+ ctrl &= ~UC2_RE;
+ ctrl &= ~UC2_TE;
+ __raw_writeb(ctrl, &base->uc2);
+
+ __raw_writeb(0, &base->umodem);
+ __raw_writeb(0, &base->uc1);
+
+ /* provide data bits, parity, stop bit, etc */
+
+ serial_setbrg();
+
+ __raw_writeb(UC2_RE | UC2_TE, &base->uc2);
+
+ return 0;
+}
+
+static struct serial_device lpuart_serial_drv = {
+ .name = "lpuart_serial",
+ .start = lpuart_serial_init,
+ .stop = NULL,
+ .setbrg = lpuart_serial_setbrg,
+ .putc = lpuart_serial_putc,
+ .puts = default_serial_puts,
+ .getc = lpuart_serial_getc,
+ .tstc = lpuart_serial_tstc,
+};
+
+void lpuart_serial_initialize(void)
+{
+ serial_register(&lpuart_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+ return &lpuart_serial_drv;
+}