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From:   Wu Hao <hao.wu@intel.com>
To:     gregkh@linuxfoundation.org, mdf@kernel.org,
        linux-fpga@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
        linux-doc@vger.kernel.org, atull@kernel.org,
        Wu Hao <hao.wu@intel.com>,
        Ananda Ravuri <ananda.ravuri@intel.com>,
        Russ Weight <russell.h.weight@intel.com>,
        Xu Yilun <yilun.xu@intel.com>
Subject: [PATCH v4 04/12] fpga: dfl: afu: add userclock sysfs interfaces.
Date:   Sun,  4 Aug 2019 18:20:14 +0800
Message-Id: <1564914022-3710-5-git-send-email-hao.wu@intel.com>
In-Reply-To: <1564914022-3710-1-git-send-email-hao.wu@intel.com>
References: <1564914022-3710-1-git-send-email-hao.wu@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This patch introduces userclock sysfs interfaces for AFU, user
could use these interfaces for clock setting to AFU.

Please note that, this is only working for port header feature
with revision 0, for later revisions, userclock setting is moved
to a separated private feature, so one revision sysfs interface
is exposed to userspace application for this purpose too.

Signed-off-by: Ananda Ravuri <ananda.ravuri@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
---
v2: rebased, and switched to use device_add/remove_groups for sysfs
v3: update kernel version and date in sysfs doc
v4: rebased.
---
 Documentation/ABI/testing/sysfs-platform-dfl-port |  35 +++++++
 drivers/fpga/dfl-afu-main.c                       | 114 +++++++++++++++++++++-
 drivers/fpga/dfl.h                                |   9 ++
 3 files changed, 157 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-platform-dfl-port b/Documentation/ABI/testing/sysfs-platform-dfl-port
index 1ab3e6f..5663441 100644
--- a/Documentation/ABI/testing/sysfs-platform-dfl-port
+++ b/Documentation/ABI/testing/sysfs-platform-dfl-port
@@ -46,3 +46,38 @@ Contact:	Wu Hao <hao.wu@intel.com>
 Description:	Read-write. Read or set AFU latency tolerance reporting value.
 		Set ltr to 1 if the AFU can tolerate latency >= 40us or set it
 		to 0 if it is latency sensitive.
+
+What:		/sys/bus/platform/devices/dfl-port.0/revision
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the revision of port header
+		feature.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcmd
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Write-only. User writes command to this interface to set
+		userclock to AFU.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqsts
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the status of issued command
+		to userclck_freqcmd.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcntrcmd
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Write-only. User writes command to this interface to set
+		userclock counter.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcntrsts
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the status of issued command
+		to userclck_freqcntrcmd.
diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
index 12175bb..407c97d 100644
--- a/drivers/fpga/dfl-afu-main.c
+++ b/drivers/fpga/dfl-afu-main.c
@@ -142,6 +142,17 @@ static int port_get_id(struct platform_device *pdev)
 static DEVICE_ATTR_RO(id);
 
 static ssize_t
+revision_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	void __iomem *base;
+
+	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+	return sprintf(buf, "%x\n", dfl_feature_revision(base));
+}
+static DEVICE_ATTR_RO(revision);
+
+static ssize_t
 ltr_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
@@ -276,6 +287,7 @@ static int port_get_id(struct platform_device *pdev)
 
 static struct attribute *port_hdr_attrs[] = {
 	&dev_attr_id.attr,
+	&dev_attr_revision.attr,
 	&dev_attr_ltr.attr,
 	&dev_attr_ap1_event.attr,
 	&dev_attr_ap2_event.attr,
@@ -284,14 +296,113 @@ static int port_get_id(struct platform_device *pdev)
 };
 ATTRIBUTE_GROUPS(port_hdr);
 
+static ssize_t
+userclk_freqcmd_store(struct device *dev, struct device_attribute *attr,
+		      const char *buf, size_t count)
+{
+	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+	u64 userclk_freq_cmd;
+	void __iomem *base;
+
+	if (kstrtou64(buf, 0, &userclk_freq_cmd))
+		return -EINVAL;
+
+	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+	mutex_lock(&pdata->lock);
+	writeq(userclk_freq_cmd, base + PORT_HDR_USRCLK_CMD0);
+	mutex_unlock(&pdata->lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(userclk_freqcmd);
+
+static ssize_t
+userclk_freqcntrcmd_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+	u64 userclk_freqcntr_cmd;
+	void __iomem *base;
+
+	if (kstrtou64(buf, 0, &userclk_freqcntr_cmd))
+		return -EINVAL;
+
+	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+	mutex_lock(&pdata->lock);
+	writeq(userclk_freqcntr_cmd, base + PORT_HDR_USRCLK_CMD1);
+	mutex_unlock(&pdata->lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(userclk_freqcntrcmd);
+
+static ssize_t
+userclk_freqsts_show(struct device *dev, struct device_attribute *attr,
+		     char *buf)
+{
+	u64 userclk_freqsts;
+	void __iomem *base;
+
+	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+	userclk_freqsts = readq(base + PORT_HDR_USRCLK_STS0);
+
+	return sprintf(buf, "0x%llx\n", (unsigned long long)userclk_freqsts);
+}
+static DEVICE_ATTR_RO(userclk_freqsts);
+
+static ssize_t
+userclk_freqcntrsts_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	u64 userclk_freqcntrsts;
+	void __iomem *base;
+
+	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+	userclk_freqcntrsts = readq(base + PORT_HDR_USRCLK_STS1);
+
+	return sprintf(buf, "0x%llx\n",
+		       (unsigned long long)userclk_freqcntrsts);
+}
+static DEVICE_ATTR_RO(userclk_freqcntrsts);
+
+static struct attribute *port_hdr_userclk_attrs[] = {
+	&dev_attr_userclk_freqcmd.attr,
+	&dev_attr_userclk_freqcntrcmd.attr,
+	&dev_attr_userclk_freqsts.attr,
+	&dev_attr_userclk_freqcntrsts.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(port_hdr_userclk);
+
 static int port_hdr_init(struct platform_device *pdev,
 			 struct dfl_feature *feature)
 {
+	int ret;
+
 	dev_dbg(&pdev->dev, "PORT HDR Init.\n");
 
 	port_reset(pdev);
 
-	return device_add_groups(&pdev->dev, port_hdr_groups);
+	ret = device_add_groups(&pdev->dev, port_hdr_groups);
+	if (ret)
+		return ret;
+
+	/*
+	 * if revision > 0, the userclock will be moved from port hdr register
+	 * region to a separated private feature.
+	 */
+	if (dfl_feature_revision(feature->ioaddr) > 0)
+		return 0;
+
+	ret = device_add_groups(&pdev->dev, port_hdr_userclk_groups);
+	if (ret)
+		device_remove_groups(&pdev->dev, port_hdr_groups);
+
+	return ret;
 }
 
 static void port_hdr_uinit(struct platform_device *pdev,
@@ -299,6 +410,7 @@ static void port_hdr_uinit(struct platform_device *pdev,
 {
 	dev_dbg(&pdev->dev, "PORT HDR UInit.\n");
 
+	device_remove_groups(&pdev->dev, port_hdr_userclk_groups);
 	device_remove_groups(&pdev->dev, port_hdr_groups);
 }
 
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 6625d73..c65ab29 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -120,6 +120,10 @@
 #define PORT_HDR_CAP		0x30
 #define PORT_HDR_CTRL		0x38
 #define PORT_HDR_STS		0x40
+#define PORT_HDR_USRCLK_CMD0	0x50
+#define PORT_HDR_USRCLK_CMD1	0x58
+#define PORT_HDR_USRCLK_STS0	0x60
+#define PORT_HDR_USRCLK_STS1	0x68
 
 /* Port Capability Register Bitfield */
 #define PORT_CAP_PORT_NUM	GENMASK_ULL(1, 0)	/* ID of this port */
@@ -346,6 +350,11 @@ static inline bool dfl_feature_is_port(void __iomem *base)
 		(FIELD_GET(DFH_ID, v) == DFH_ID_FIU_PORT);
 }
 
+static inline u8 dfl_feature_revision(void __iomem *base)
+{
+	return (u8)FIELD_GET(DFH_REVISION, readq(base + DFH));
+}
+
 /**
  * struct dfl_fpga_enum_info - DFL FPGA enumeration information
  *
-- 
1.8.3.1