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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/mach-davinci/serial.c
Initial import
Diffstat (limited to 'arch/arm/mach-davinci/serial.c')
-rw-r--r--arch/arm/mach-davinci/serial.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/serial.c b/arch/arm/mach-davinci/serial.c
new file mode 100644
index 000000000..951b620bf
--- /dev/null
+++ b/arch/arm/mach-davinci/serial.c
@@ -0,0 +1,106 @@
+/*
+ * TI DaVinci serial driver
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <mach/serial.h>
+#include <mach/cputype.h>
+
+static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
+ int value)
+{
+ offset <<= p->regshift;
+
+ WARN_ONCE(!p->membase, "unmapped write: uart[%d]\n", offset);
+
+ __raw_writel(value, p->membase + offset);
+}
+
+static void __init davinci_serial_reset(struct plat_serial8250_port *p)
+{
+ unsigned int pwremu = 0;
+
+ serial_write_reg(p, UART_IER, 0); /* disable all interrupts */
+
+ /* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */
+ serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);
+ mdelay(10);
+
+ pwremu |= (0x3 << 13);
+ pwremu |= 0x1;
+ serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);
+
+ if (cpu_is_davinci_dm646x())
+ serial_write_reg(p, UART_DM646X_SCR,
+ UART_DM646X_SCR_TX_WATERMARK);
+}
+
+int __init davinci_serial_init(struct platform_device *serial_dev)
+{
+ int i, ret = 0;
+ struct device *dev;
+ struct plat_serial8250_port *p;
+ struct clk *clk;
+
+ /*
+ * Make sure the serial ports are muxed on at this point.
+ * You have to mux them off in device drivers later on if not needed.
+ */
+ for (i = 0; serial_dev[i].dev.platform_data != NULL; i++) {
+ dev = &serial_dev[i].dev;
+ p = dev->platform_data;
+
+ ret = platform_device_register(&serial_dev[i]);
+ if (ret)
+ continue;
+
+ clk = clk_get(dev, NULL);
+ if (IS_ERR(clk)) {
+ pr_err("%s:%d: failed to get UART%d clock\n",
+ __func__, __LINE__, i);
+ continue;
+ }
+
+ clk_prepare_enable(clk);
+
+ p->uartclk = clk_get_rate(clk);
+
+ if (!p->membase && p->mapbase) {
+ p->membase = ioremap(p->mapbase, SZ_4K);
+
+ if (p->membase)
+ p->flags &= ~UPF_IOREMAP;
+ else
+ pr_err("uart regs ioremap failed\n");
+ }
+
+ if (p->membase && p->type != PORT_AR7)
+ davinci_serial_reset(p);
+ }
+ return ret;
+}