[PATCH 2/2] driver/serial: add driver for the mxs application uart
Marc Kleine-Budde
mkl at pengutronix.de
Tue Feb 26 13:34:50 EST 2013
Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
---
drivers/serial/Makefile | 1 +
drivers/serial/serial_auart.c | 257 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 258 insertions(+)
create mode 100644 drivers/serial/serial_auart.c
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 893e282..6b90593 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -21,3 +21,4 @@ obj-$(CONFIG_DRIVER_SERIAL_ALTERA) += serial_altera.o
obj-$(CONFIG_DRIVER_SERIAL_ALTERA_JTAG) += serial_altera_jtag.o
obj-$(CONFIG_DRIVER_SERIAL_PXA) += serial_pxa.o
obj-$(CONFIG_DRIVER_SERIAL_OMAP4_USBBOOT) += serial_omap4_usbboot.o
+obj-$(CONFIG_DRIVER_SERIAL_AUART) += serial_auart.o
diff --git a/drivers/serial/serial_auart.c b/drivers/serial/serial_auart.c
new file mode 100644
index 0000000..5208a5d
--- /dev/null
+++ b/drivers/serial/serial_auart.c
@@ -0,0 +1,257 @@
+/*
+ * (C) 2013 Marc Kleine-Budde <mkl at pengutronix.de>
+ *
+ * Based on the stm-serial driver:
+ *
+ * (C) Copyright 2010 Juergen Beisert - Pengutronix
+ *
+ * ...also based on the u-boot auart driver:
+ *
+ * (C) 2011 Wolfgang Ocker <weo at reccoware.de>
+ *
+ * Based on the standard DUART serial driver:
+ *
+ * (C) 2007 Sascha Hauer <s.hauer at pengutronix.de>
+ *
+ * (C) Copyright 2009-2010 Freescale Semiconductor, Inc.
+ *
+ * Further based on the Linux mxs-auart.c driver:
+ *
+ * Freescale STMP37XX/STMP378X Application UART driver
+ *
+ * Author: dmitry pervushin <dimka at embeddedalley.com>
+ *
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ *
+ * 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.
+ *
+ */
+
+#include <common.h>
+#include <gpio.h>
+#include <init.h>
+#include <io.h>
+#include <malloc.h>
+#include <notifier.h>
+
+#include <mach/clock.h>
+#include <mach/imx-regs.h>
+
+#define HW_UARTAPP_CTRL0 (0x00000000)
+#define HW_UARTAPP_CTRL0_CLR (0x00000008)
+#define BM_UARTAPP_CTRL0_SFTRST (0x80000000)
+#define BM_UARTAPP_CTRL0_CLKGATE (0x40000000)
+
+#define HW_UARTAPP_CTRL2 (0x00000020)
+#define HW_UARTAPP_CTRL2_SET (0x00000024)
+#define HW_UARTAPP_CTRL2_CLR (0x00000028)
+#define BM_UARTAPP_CTRL2_CTSEN (0x00008000)
+#define BM_UARTAPP_CTRL2_RTSEN (0x00004000)
+#define BM_UARTAPP_CTRL2_RXE (0x00000200)
+#define BM_UARTAPP_CTRL2_TXE (0x00000100)
+#define BM_UARTAPP_CTRL2_USE_LCR2 (0x00000040)
+#define BM_UARTAPP_CTRL2_UARTEN (0x00000001)
+
+#define HW_UARTAPP_LINECTRL (0x00000030)
+#define BM_UARTAPP_LINECTRL_FEN (0x00000010)
+
+#define BM_UARTAPP_LINECTRL_BAUD_DIVFRAC (0x00003F00)
+#define BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(v) \
+ (((v) << 8) & BM_UARTAPP_LINECTRL_BAUD_DIVFRAC)
+
+#define BP_UARTAPP_LINECTRL_BAUD_DIVINT (16)
+#define BM_UARTAPP_LINECTRL_BAUD_DIVINT (0xFFFF0000)
+#define BF_UARTAPP_LINECTRL_BAUD_DIVINT(v) \
+ (((v) << 16) & BM_UARTAPP_LINECTRL_BAUD_DIVINT)
+
+#define BP_UARTAPP_LINECTRL_WLEN (5)
+#define BM_UARTAPP_LINECTRL_WLEN (0x00000060)
+#define BF_UARTAPP_LINECTRL_WLEN(v) \
+ (((v) << 5) & BM_UARTAPP_LINECTRL_WLEN)
+
+#define HW_UARTAPP_LINECTRL2_SET (0x00000044)
+
+#define HW_UARTAPP_INTR (0x00000050)
+
+#define HW_UARTAPP_DATA (0x00000060)
+#define BM_UARTAPP_STAT_RXFE (0x01000000)
+#define BM_UARTAPP_STAT_TXFE (0x08000000)
+
+#define HW_UARTAPP_STAT (0x00000070)
+#define BM_UARTAPP_STAT_TXFF (0x02000000)
+
+struct auart_priv {
+ struct console_device cdev;
+ int baudrate;
+ struct notifier_block notify;
+ void __iomem *base;
+};
+
+static void auart_serial_putc(struct console_device *cdev, char c)
+{
+ struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+ /* Wait for room in TX FIFO */
+ while (readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFF)
+ ;
+
+ writel(c, priv->base + HW_UARTAPP_DATA);
+}
+
+static int auart_serial_tstc(struct console_device *cdev)
+{
+ struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+ /* Check if RX FIFO is not empty */
+ return !(readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_RXFE);
+}
+
+static int auart_serial_getc(struct console_device *cdev)
+{
+ struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+ /* Wait while TX FIFO is empty */
+ while (!auart_serial_tstc(cdev))
+ ;
+
+ return readl(priv->base + HW_UARTAPP_DATA) & 0xff;
+}
+
+static void auart_serial_flush(struct console_device *cdev)
+{
+ struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+ /* Wait for TX FIFO empty */
+ while (readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFE)
+ ;
+}
+
+static int auart_serial_setbaudrate(struct console_device *cdev, int new_baudrate)
+{
+ struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+ uint32_t ctrl2, quot, reg;
+
+ /* Disable everything */
+ ctrl2 = readl(priv->base + HW_UARTAPP_CTRL2);
+ writel(0x0, priv->base + HW_UARTAPP_CTRL2);
+
+ /* Calculate and set baudrate */
+ quot = (imx_get_xclk() * 32) / new_baudrate;
+ reg = BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(quot & 0x3F) |
+ BF_UARTAPP_LINECTRL_BAUD_DIVINT(quot >> 6) |
+ BF_UARTAPP_LINECTRL_WLEN(3) |
+ BM_UARTAPP_LINECTRL_FEN;
+
+ writel(reg, priv->base + HW_UARTAPP_LINECTRL);
+
+ /* Re-enable debug UART */
+ writel(ctrl2, priv->base + HW_UARTAPP_CTRL2);
+
+ priv->baudrate = new_baudrate;
+
+ return 0;
+}
+
+static int auart_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
+{
+ struct auart_priv *priv = container_of(nb, struct auart_priv, notify);
+
+ return auart_serial_setbaudrate(&priv->cdev, priv->baudrate);
+}
+
+static void auart_reset(struct auart_priv *priv)
+{
+ int i;
+
+ writel(BM_UARTAPP_CTRL0_SFTRST, priv->base + HW_UARTAPP_CTRL0_CLR);
+
+ for (i = 0; i < 10000; i++) {
+ uint32_t reg;
+
+ reg = readl(priv->base + HW_UARTAPP_CTRL0);
+ if (!(reg & BM_UARTAPP_CTRL0_SFTRST))
+ break;
+ }
+
+ writel(BM_UARTAPP_CTRL0_CLKGATE, priv->base + HW_UARTAPP_CTRL0_CLR);
+}
+
+static void auart_serial_init_port(struct auart_priv *priv)
+{
+ auart_reset(priv);
+
+ /* Disable UART */
+ writel(0x0, priv->base + HW_UARTAPP_CTRL2);
+ /* Mask interrupts */
+ writel(0x0, priv->base + HW_UARTAPP_INTR);
+}
+
+static int auart_serial_probe(struct device_d *dev)
+{
+ struct auart_priv *priv;
+ struct console_device *cdev;
+
+ priv = xzalloc(sizeof *priv);
+ cdev = &priv->cdev;
+
+ cdev->f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
+ cdev->tstc = auart_serial_tstc;
+ cdev->putc = auart_serial_putc;
+ cdev->getc = auart_serial_getc;
+ cdev->flush = auart_serial_flush;
+ cdev->setbrg = auart_serial_setbaudrate;
+ cdev->dev = dev;
+
+ dev->priv = priv;
+ priv->base = dev_request_mem_region(dev, 0);
+
+ auart_serial_init_port(priv);
+ auart_serial_setbaudrate(cdev, CONFIG_BAUDRATE);
+
+ /* Disable RTS/CTS, enable Rx, Tx, UART */
+ writel(BM_UARTAPP_CTRL2_RTSEN | BM_UARTAPP_CTRL2_CTSEN |
+ BM_UARTAPP_CTRL2_USE_LCR2,
+ priv->base + HW_UARTAPP_CTRL2_CLR);
+ writel(BM_UARTAPP_CTRL2_RXE | BM_UARTAPP_CTRL2_TXE |
+ BM_UARTAPP_CTRL2_UARTEN,
+ priv->base + HW_UARTAPP_CTRL2_SET);
+
+ console_register(cdev);
+ priv->notify.notifier_call = auart_clocksource_clock_change;
+ clock_register_client(&priv->notify);
+
+ return 0;
+}
+
+
+static void auart_serial_remove(struct device_d *dev)
+{
+ struct auart_priv *priv = dev->priv;
+
+ auart_serial_flush(&priv->cdev);
+ console_unregister(&priv->cdev);
+ free(priv);
+}
+
+static struct driver_d auart_serial_driver = {
+ .name = "auart_serial",
+ .probe = auart_serial_probe,
+ .remove = auart_serial_remove,
+};
+
+static int auart_serial_init(void)
+{
+ platform_driver_register(&auart_serial_driver);
+ return 0;
+}
+
+console_initcall(auart_serial_init);
--
1.7.10.4
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