From: Kevin Brace <kevinbrace@xxxxxxxxxxxxxxxxxxxx>
Note that the code here is GPL based.
Signed-off-by: Kevin Brace <kevinbrace@xxxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/via/via_i2c.c | 209 ++++++++++++++++++++++++++++++++++
1 file changed, 209 insertions(+)
create mode 100644 drivers/gpu/drm/via/via_i2c.c
diff --git a/drivers/gpu/drm/via/via_i2c.c b/drivers/gpu/drm/via/via_i2c.c
new file mode 100644
index 000000000000..f2e8b118754e
--- /dev/null
+++ b/drivers/gpu/drm/via/via_i2c.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2012 James Simmons. All Rights Reserved.
+ * Copyright 1998-2009 VIA Technologies, Inc. All Rights Reserved.
+ * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
+ *
+ * Author(s):
+ * James Simmons <jsimmons@xxxxxxxxxxxxx>
+ */
+
+#include <linux/delay.h>
+
+#include "via_drv.h"
+
+enum viafb_i2c_adap;
+
+#include <linux/via_i2c.h>
+
+#define SERIAL 0
+#define GPIO 1
+
+static struct via_i2c_stuff via_i2c_par[5];
+
+static void via_i2c_setsda(void *data, int state)
+{
+ struct via_i2c_stuff *i2c = data;
+ struct drm_device *dev = i2c_get_adapdata(&i2c->adapter);
+ struct via_drm_priv *dev_priv = to_via_drm_priv(dev);
+ u8 value, mask;
+
+ if (i2c->is_active == GPIO) {
+ mask = state ? BIT(6) : BIT(6) | BIT(4);
+ value = state ? 0x00 : BIT(6);
+ } else {
+ value = state ? BIT(4) | BIT(0) : BIT(0);
+ mask = BIT(4) | BIT(0);
+ }
+
+ svga_wseq_mask(VGABASE, i2c->i2c_port, value, mask);
+}
+
+static void via_i2c_setscl(void *data, int state)
+{
+ struct via_i2c_stuff *i2c = data;
+ struct drm_device *dev = i2c_get_adapdata(&i2c->adapter);
+ struct via_drm_priv *dev_priv = to_via_drm_priv(dev);
+ u8 value, mask;
+
+ if (i2c->is_active == GPIO) {
+ mask = state ? BIT(7) : BIT(7) | BIT(5);
+ value = state ? 0x00 : BIT(7);
+ } else {
+ value = state ? BIT(5) | BIT(0) : BIT(0);
+ mask = BIT(5) | BIT(0);
+ }
+
+ svga_wseq_mask(VGABASE, i2c->i2c_port, value, mask);
+}
+
+static int via_i2c_getsda(void *data)
+{
+ struct via_i2c_stuff *i2c = data;
+ struct drm_device *dev = i2c_get_adapdata(&i2c->adapter);
+ struct via_drm_priv *dev_priv = to_via_drm_priv(dev);
+
+ return vga_rseq(VGABASE, i2c->i2c_port) & BIT(2);
+}
+
+static int via_i2c_getscl(void *data)
+{
+ struct via_i2c_stuff *i2c = data;
+ struct drm_device *dev = i2c_get_adapdata(&i2c->adapter);
+ struct via_drm_priv *dev_priv = to_via_drm_priv(dev);
+
+ return vga_rseq(VGABASE, i2c->i2c_port) & BIT(3);
+}
+
+struct i2c_adapter *via_find_ddc_bus(int port)
+{
+ struct i2c_adapter *adapter = NULL;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(via_i2c_par); i++) {
+ struct via_i2c_stuff *i2c = &via_i2c_par[i];
+
+ if (i2c->i2c_port == port) {
+ adapter = &i2c->adapter;
+ break;
+ }
+ }
+ return adapter;
+}
+
+static int create_i2c_bus(struct drm_device *dev,
+ struct via_i2c_stuff *i2c_par)
+{
+ struct i2c_adapter *adapter = &i2c_par->adapter;
+ struct i2c_algo_bit_data *algo = &i2c_par->algo;
+
+ algo->setsda = via_i2c_setsda;
+ algo->setscl = via_i2c_setscl;
+ algo->getsda = via_i2c_getsda;
+ algo->getscl = via_i2c_getscl;
+ algo->udelay = 15;
+ algo->timeout = usecs_to_jiffies(2200); /* from VESA */
+ algo->data = i2c_par;
+
+ sprintf(adapter->name, "via i2c bit bus 0x%02x", i2c_par->i2c_port);
+ adapter->owner = THIS_MODULE;
+ adapter->class = I2C_CLASS_DDC;
+ adapter->algo_data = algo;
+ i2c_set_adapdata(adapter, dev);
+
+ /* Raise SCL and SDA */
+ via_i2c_setsda(i2c_par, 1);
+ via_i2c_setscl(i2c_par, 1);
+ udelay(20);
+
+ return i2c_bit_add_bus(adapter);
+}
+
+void via_i2c_readbytes(struct i2c_adapter *adapter,
+ u8 slave_addr, char offset,
+ u8 *buffer, unsigned int size)
+{
+ u8 out_buf[2];
+ u8 in_buf[2];
+ struct i2c_msg msgs[] = {
+ {
+ .addr = slave_addr,
+ .flags = 0,
+ .len = 1,
+ .buf = out_buf,
+ },
+ {
+ .addr = slave_addr,
+ .flags = I2C_M_RD,
+ .len = size,
+ .buf = in_buf,
+ }
+ };
+
+ out_buf[0] = offset;
+ out_buf[1] = 0;
+
+ if (i2c_transfer(adapter, msgs, 2) != 2)
+ printk(KERN_WARNING "%s failed\n", __func__);
+ else
+ *buffer = in_buf[0];
+}
+
+void via_i2c_writebytes(struct i2c_adapter *adapter,
+ u8 slave_addr, char offset,
+ u8 *data, unsigned int size)
+{
+ struct i2c_msg msg = { 0 };
+ u8 *out_buf;
+
+ out_buf = kzalloc(size + 1, GFP_KERNEL);
+ out_buf[0] = offset;
+ memcpy(&out_buf[1], data, size);
+ msg.addr = slave_addr;
+ msg.flags = 0;
+ msg.len = size + 1;
+ msg.buf = out_buf;
+
+ if (i2c_transfer(adapter, &msg, 1) != 1)
+ printk(KERN_WARNING "%s failed\n", __func__);
+
+ kfree(out_buf);
+}
+
+void via_i2c_reg_init(struct via_drm_priv *dev_priv)
+{
+ svga_wseq_mask(VGABASE, 0x31, 0x30, 0x30);
+ svga_wseq_mask(VGABASE, 0x26, 0x30, 0x30);
+ vga_wseq(VGABASE, 0x2C, 0xc2);
+ vga_wseq(VGABASE, 0x3D, 0xc0);
+ svga_wseq_mask(VGABASE, 0x2C, 0x30, 0x30);
+ svga_wseq_mask(VGABASE, 0x3D, 0x30, 0x30);
+}
+
+int via_i2c_init(struct drm_device *dev)
+{
+ int types[] = { SERIAL, SERIAL, GPIO, GPIO, GPIO };
+ int ports[] = { 0x26, 0x31, 0x25, 0x2C, 0x3D };
+ int count = ARRAY_SIZE(via_i2c_par), ret, i;
+ struct via_i2c_stuff *i2c = via_i2c_par;
+
+ for (i = 0; i < count; i++) {
+ i2c->is_active = types[i];
+ i2c->i2c_port = ports[i];
+
+ ret = create_i2c_bus(dev, i2c);
+ if (ret < 0)
+ DRM_ERROR("cannot create i2c bus %x:%d\n",
+ ports[i], ret);
+ i2c++;
+ }
+ return 0;
+}
+
+void via_i2c_exit(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(via_i2c_par); i++)
+ i2c_del_adapter(&via_i2c_par->adapter);
+}
--
2.35.1
