[PATCH v3 08/32] drm/via: Add via_crtc_hw.c

[Kevin Brace]

From: Kevin Brace <kevinbrace at bracecomputerlab.com>

Signed-off-by: Kevin Brace <kevinbrace at bracecomputerlab.com>
---
 drivers/gpu/drm/via/via_crtc_hw.c | 91 +++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 drivers/gpu/drm/via/via_crtc_hw.c

diff --git a/drivers/gpu/drm/via/via_crtc_hw.c b/drivers/gpu/drm/via/via_crtc_hw.c
new file mode 100644
index 000000000000..f5446da52c0f
--- /dev/null
+++ b/drivers/gpu/drm/via/via_crtc_hw.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2012 James Simmons. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) OR COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author(s):
+ * James Simmons <jsimmons at infradead.org>
+ */
+
+#include <video/vga.h>
+
+#include "via_crtc_hw.h"
+
+/*
+ * load_register_table enables the ability to set entire
+ * tables of registers. For each register defined by the
+ * port and the index for that register is programmed
+ * with a masked value.
+ */
+void
+load_register_tables(void __iomem *regbase, struct vga_registers *regs)
+{
+	u8 cr_index, orig, reg_mask, data;
+	unsigned int i;
+	u16 port;
+
+	for (i = 0; i < regs->count; i++) {
+		reg_mask = regs->regs[i].start_bit;
+		data = regs->regs[i].end_bit;
+		cr_index = regs->regs[i].io_addr;
+		port = regs->regs[i].ioport;
+
+		vga_w(regbase, port, cr_index);
+		orig = (vga_r(regbase, port + 1) & ~reg_mask);
+		vga_w(regbase, port + 1, ((data & reg_mask) | orig));
+	}
+}
+
+/*
+ * Due to the limitation of how much data you can write to a single
+ * register we run into data that can't be written in only one register.
+ * So load_value_to_register was developed to be able to define register
+ * tables that can load different bit ranges of the data to different
+ * registers.
+ */
+void
+load_value_to_registers(void __iomem *regbase, struct vga_registers *regs,
+			unsigned int value)
+{
+	unsigned int bit_num = 0, shift_next_reg, reg_mask;
+	u8 start_index, end_index, cr_index, orig;
+	unsigned int data, i, j;
+	u16 get_bit, port;
+
+	for (i = 0; i < regs->count; i++) {
+		start_index = regs->regs[i].start_bit;
+		end_index = regs->regs[i].end_bit;
+		cr_index = regs->regs[i].io_addr;
+		port = regs->regs[i].ioport;
+		reg_mask = data = 0;
+
+		shift_next_reg = bit_num;
+		for (j = start_index; j <= end_index; j++) {
+			reg_mask = reg_mask | (1 << j);
+			get_bit = (value & (1 << bit_num));
+			data |= ((get_bit >> shift_next_reg) << start_index);
+			bit_num++;
+		}
+
+		vga_w(regbase, port, cr_index);
+		orig = (vga_r(regbase, port + 1) & ~reg_mask);
+		vga_w(regbase, port + 1, ((data & reg_mask) | orig));
+	}
+}
--
2.35.1