Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / powerpc / boot / virtex.c

diff --git a/kernel/arch/powerpc/boot/virtex.c b/kernel/arch/powerpc/boot/virtex.c
new file mode 100644 (file)
index 0000000..f622805
--- /dev/null
+++ b/kernel/arch/powerpc/boot/virtex.c
@@ -0,0 +1,100 @@
+/*
+ * The platform specific code for virtex devices since a boot loader is not
+ * always used.
+ *
+ * (C) Copyright 2008 Xilinx, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include "ops.h"
+#include "io.h"
+#include "stdio.h"
+
+#define UART_DLL               0       /* Out: Divisor Latch Low */
+#define UART_DLM               1       /* Out: Divisor Latch High */
+#define UART_FCR               2       /* Out: FIFO Control Register */
+#define UART_FCR_CLEAR_RCVR    0x02    /* Clear the RCVR FIFO */
+#define UART_FCR_CLEAR_XMIT    0x04    /* Clear the XMIT FIFO */
+#define UART_LCR               3       /* Out: Line Control Register */
+#define UART_MCR               4       /* Out: Modem Control Register */
+#define UART_MCR_RTS           0x02    /* RTS complement */
+#define UART_MCR_DTR           0x01    /* DTR complement */
+#define UART_LCR_DLAB          0x80    /* Divisor latch access bit */
+#define UART_LCR_WLEN8         0x03    /* Wordlength: 8 bits */
+
+static int virtex_ns16550_console_init(void *devp)
+{
+       unsigned char *reg_base;
+       u32 reg_shift, reg_offset, clk, spd;
+       u16 divisor;
+       int n;
+
+       if (dt_get_virtual_reg(devp, (void **)&reg_base, 1) < 1)
+               return -1;
+
+       n = getprop(devp, "reg-offset", &reg_offset, sizeof(reg_offset));
+       if (n == sizeof(reg_offset))
+               reg_base += reg_offset;
+
+       n = getprop(devp, "reg-shift", &reg_shift, sizeof(reg_shift));
+       if (n != sizeof(reg_shift))
+               reg_shift = 0;
+
+       n = getprop(devp, "current-speed", (void *)&spd, sizeof(spd));
+       if (n != sizeof(spd))
+               spd = 9600;
+
+       /* should there be a default clock rate?*/
+       n = getprop(devp, "clock-frequency", (void *)&clk, sizeof(clk));
+       if (n != sizeof(clk))
+               return -1;
+
+       divisor = clk / (16 * spd);
+
+       /* Access baud rate */
+       out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_DLAB);
+
+       /* Baud rate based on input clock */
+       out_8(reg_base + (UART_DLL << reg_shift), divisor & 0xFF);
+       out_8(reg_base + (UART_DLM << reg_shift), divisor >> 8);
+
+       /* 8 data, 1 stop, no parity */
+       out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_WLEN8);
+
+       /* RTS/DTR */
+       out_8(reg_base + (UART_MCR << reg_shift), UART_MCR_RTS | UART_MCR_DTR);
+
+       /* Clear transmitter and receiver */
+       out_8(reg_base + (UART_FCR << reg_shift),
+                               UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
+       return 0;
+}
+
+/* For virtex, the kernel may be loaded without using a bootloader and if so
+   some UARTs need more setup than is provided in the normal console init
+*/
+int platform_specific_init(void)
+{
+       void *devp;
+       char devtype[MAX_PROP_LEN];
+       char path[MAX_PATH_LEN];
+
+       devp = finddevice("/chosen");
+       if (devp == NULL)
+               return -1;
+
+       if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0) {
+               devp = finddevice(path);
+               if (devp == NULL)
+                       return -1;
+
+               if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
+                               && !strcmp(devtype, "serial")
+                               && (dt_is_compatible(devp, "ns16550")))
+                               virtex_ns16550_console_init(devp);
+       }
+       return 0;
+}