Attachment 53296 Details for Bug 32343 – use hw i2c

[patch] use hw i2c

0001-drm-radeon-kms-dce3-add-support-for-hw-i2c-using-ato.patch (text/plain), 7.41 KB, created by Alex Deucher on 2011-11-08 07:02:56 UTC

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Creator: Alex Deucher

Created: 2011-11-08 07:02:56 UTC

Size: 7.41 KB

patch

obsolete

>From 29d53ded34504a650486d438ddc69ad63634bf34 Mon Sep 17 00:00:00 2001
>From: Alex Deucher <alexander.deucher@amd.com>
>Date: Tue, 8 Nov 2011 09:55:01 -0500
>Subject: [PATCH] drm/radeon/kms/dce3+: add support for hw i2c using atom
>
>Starting with DCE3 hardware, atom contains a general purpose
>ProcessI2cChannelTransaction similar to ProcessAuxChannelTransaction.
>
>Add an implementation using the atom tables for DCE3+ hardware.
>
>This should be a little less CPU intensive than bit banging and
>may work better in certain cases.
>
>Enable it by setting the radeon hw_i2c module parameter to 1.  E.g.,
>radeon.hw_i2c=1
>on the kernel command line in grub.
>
>Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
>---
> drivers/gpu/drm/radeon/Makefile       |    3 +-
> drivers/gpu/drm/radeon/atombios_i2c.c |  139 +++++++++++++++++++++++++++++++++
> drivers/gpu/drm/radeon/radeon_i2c.c   |   21 +++++
> 3 files changed, 162 insertions(+), 1 deletions(-)
> create mode 100644 drivers/gpu/drm/radeon/atombios_i2c.c
>
>diff --git a/drivers/gpu/drm/radeon/Makefile b/drivers/gpu/drm/radeon/Makefile
>index cf8b4bc..87fdad2 100644
>--- a/drivers/gpu/drm/radeon/Makefile
>+++ b/drivers/gpu/drm/radeon/Makefile
>@@ -70,7 +70,8 @@ radeon-y += radeon_device.o radeon_asic.o radeon_kms.o \
> 	r200.o radeon_legacy_tv.o r600_cs.o r600_blit.o r600_blit_shaders.o \
> 	r600_blit_kms.o radeon_pm.o atombios_dp.o r600_audio.o r600_hdmi.o \
> 	evergreen.o evergreen_cs.o evergreen_blit_shaders.o evergreen_blit_kms.o \
>-	radeon_trace_points.o ni.o cayman_blit_shaders.o atombios_encoders.o
>+	radeon_trace_points.o ni.o cayman_blit_shaders.o atombios_encoders.o \
>+	atombios_i2c.o
> 
> radeon-$(CONFIG_COMPAT) += radeon_ioc32.o
> radeon-$(CONFIG_VGA_SWITCHEROO) += radeon_atpx_handler.o
>diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c
>new file mode 100644
>index 0000000..44d87b6
>--- /dev/null
>+++ b/drivers/gpu/drm/radeon/atombios_i2c.c
>@@ -0,0 +1,139 @@
>+/*
>+ * Copyright 2011 Advanced Micro Devices, Inc.
>+ *
>+ * 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, sublicense,
>+ * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
>+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(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.
>+ *
>+ * Authors: Alex Deucher
>+ *
>+ */
>+#include "drmP.h"
>+#include "radeon_drm.h"
>+#include "radeon.h"
>+#include "atom.h"
>+
>+#define TARGET_HW_I2C_CLOCK 50
>+
>+/* these are a limitation of ProcessI2cChannelTransaction not the hw */
>+#define ATOM_MAX_HW_I2C_WRITE 2
>+#define ATOM_MAX_HW_I2C_READ  255
>+
>+static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
>+				 u8 slave_addr, u8 flags,
>+				 u8 *buf, u8 num)
>+{
>+	struct drm_device *dev = chan->dev;
>+	struct radeon_device *rdev = dev->dev_private;
>+	PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
>+	int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
>+	unsigned char *base;
>+	u16 out;
>+
>+	memset(&args, 0, sizeof(args));
>+
>+	base = (unsigned char *)rdev->mode_info.atom_context->scratch;
>+
>+	if (flags & HW_I2C_WRITE) {
>+		if (num > ATOM_MAX_HW_I2C_WRITE) {
>+			DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 2)\n", num);
>+			return -EINVAL;
>+		}
>+		memcpy(&out, buf, num);
>+		args.lpI2CDataOut = cpu_to_le16(out);
>+	} else {
>+		if (num > ATOM_MAX_HW_I2C_READ) {
>+			DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
>+			return -EINVAL;
>+		}
>+	}
>+
>+	args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
>+	args.ucRegIndex = 0;
>+	args.ucTransBytes = num;
>+	args.ucSlaveAddr = slave_addr << 1;
>+	args.ucLineNumber = chan->rec.i2c_id;
>+
>+	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
>+
>+	/* error */
>+	if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
>+		DRM_DEBUG_KMS("hw_i2c error\n");
>+		return -EIO;
>+	}
>+
>+	if (!(flags & HW_I2C_WRITE))
>+		memcpy(buf, base, num);
>+
>+	return 0;
>+}
>+
>+int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
>+			    struct i2c_msg *msgs, int num)
>+{
>+	struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
>+	struct i2c_msg *p;
>+	int i, remaining, current_count, buffer_offset, max_bytes, ret;
>+	u8 buf = 0, flags;
>+
>+	/* check for bus probe */
>+	p = &msgs[0];
>+	if ((num == 1) && (p->len == 0)) {
>+		ret = radeon_process_i2c_ch(i2c,
>+					    p->addr, HW_I2C_WRITE,
>+					    &buf, 1);
>+		if (ret)
>+			return ret;
>+		else
>+			return num;
>+	}
>+
>+	for (i = 0; i < num; i++) {
>+		p = &msgs[i];
>+		remaining = p->len;
>+		buffer_offset = 0;
>+		/* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
>+		if (p->flags & I2C_M_RD) {
>+			max_bytes = ATOM_MAX_HW_I2C_READ;
>+			flags = HW_I2C_READ;
>+		} else {
>+			max_bytes = ATOM_MAX_HW_I2C_WRITE;
>+			flags = HW_I2C_WRITE;
>+		}
>+		while (remaining) {
>+			if (remaining > max_bytes)
>+				current_count = max_bytes;
>+			else
>+				current_count = remaining;
>+			ret = radeon_process_i2c_ch(i2c,
>+						    p->addr, flags,
>+						    &p->buf[buffer_offset], current_count);
>+			if (ret)
>+				return ret;
>+			remaining -= current_count;
>+			buffer_offset += current_count;
>+		}
>+	}
>+
>+	return num;
>+}
>+
>+u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap)
>+{
>+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
>+}
>+
>diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
>index 5cabf82..d2bccb5 100644
>--- a/drivers/gpu/drm/radeon/radeon_i2c.c
>+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
>@@ -28,6 +28,10 @@
> #include "radeon.h"
> #include "atom.h"
> 
>+extern int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
>+				   struct i2c_msg *msgs, int num);
>+extern u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap);
>+
> /**
>  * radeon_ddc_probe
>  *
>@@ -880,6 +884,11 @@ static const struct i2c_algorithm radeon_i2c_algo = {
> 	.functionality = radeon_hw_i2c_func,
> };
> 
>+static const struct i2c_algorithm radeon_atom_i2c_algo = {
>+	.master_xfer = radeon_atom_hw_i2c_xfer,
>+	.functionality = radeon_atom_hw_i2c_func,
>+};
>+
> struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
> 					  struct radeon_i2c_bus_rec *rec,
> 					  const char *name)
>@@ -911,6 +920,18 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
> 			DRM_ERROR("Failed to register hw i2c %s\n", name);
> 			goto out_free;
> 		}
>+	} else if (rec->hw_capable &&
>+		   radeon_hw_i2c &&
>+		   ASIC_IS_DCE3(rdev)) {
>+		/* hw i2c using atom */
>+		snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
>+			 "Radeon i2c hw bus %s", name);
>+		i2c->adapter.algo = &radeon_atom_i2c_algo;
>+		ret = i2c_add_adapter(&i2c->adapter);
>+		if (ret) {
>+			DRM_ERROR("Failed to register hw i2c %s\n", name);
>+			goto out_free;
>+		}
> 	} else {
> 		/* set the radeon bit adapter */
> 		snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
>-- 
>1.7.3.4
>

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