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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/powerpc/boot/virtex.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/boot/virtex.c')
-rw-r--r--arch/powerpc/boot/virtex.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/powerpc/boot/virtex.c b/arch/powerpc/boot/virtex.c
new file mode 100644
index 000000000..f622805f8
--- /dev/null
+++ b/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;
+}