[PATCH v6 2/4] fpga pr ip: Core driver support for Altera Partial Reconfiguration IP.

[matthew . gerlach]

From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>

Adding the core functions necessary for a fpga-mgr driver
for the Altera Partial IP component.  It is intended for
these functions to be used by the various bus implementations
like the platform bus or the PCIe bus.

Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
---
v6:
    Suggestions from Anatolij Gustschin <agust@xxxxxxx>
    s/pr_err/dev_err/g
    Change for loop to do/while to handle config_complete_timeout_us == 0
    move altera-pr-ip-core.h to include/linux/fpga
v5:
    Fix comment as suggested by Rob Herring <robh@xxxxxxxxxx>
v4:
    v3 patch set mistakenly sent out labeled as v4
v3:
    s/alt_pr_probe/alt_pr_register/
    s/alt_pr_remove/alt_pr_unregister/
---
 drivers/fpga/Kconfig                   |   5 +
 drivers/fpga/Makefile                  |   1 +
 drivers/fpga/altera-pr-ip-core.c       | 220 +++++++++++++++++++++++++++++++++
 include/linux/fpga/altera-pr-ip-core.h |  29 +++++
 4 files changed, 255 insertions(+)
 create mode 100644 drivers/fpga/altera-pr-ip-core.c
 create mode 100644 include/linux/fpga/altera-pr-ip-core.h

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index dee470f..9dd8da1 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -76,6 +76,11 @@ config ALTERA_FREEZE_BRIDGE
 	  isolate one region of the FPGA from the busses while that
 	  region is being reprogrammed.
 
+config ALTERA_PR_IP_CORE
+        tristate "Altera Partial Reconfiguration IP Core"
+        help
+          Core driver support for Altera Partial Reconfiguration IP component
+
 endif # FPGA
 
 endmenu
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index a5ee3ff..916d67e 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_FPGA_MGR_SOCFPGA)		+= socfpga.o
 obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10)	+= socfpga-a10.o
 obj-$(CONFIG_FPGA_MGR_TS73XX)		+= ts73xx-fpga.o
 obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
+obj-$(CONFIG_ALTERA_PR_IP_CORE)         += altera-pr-ip-core.o
 
 # FPGA Bridge Drivers
 obj-$(CONFIG_FPGA_BRIDGE)		+= fpga-bridge.o
diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
new file mode 100644
index 0000000..a7b31f9
--- /dev/null
+++ b/drivers/fpga/altera-pr-ip-core.c
@@ -0,0 +1,220 @@
+/*
+ * Driver for Altera Partial Reconfiguration IP Core
+ *
+ * Copyright (C) 2016-2017 Intel Corporation
+ *
+ * Based on socfpga-a10.c Copyright (C) 2015-2016 Altera Corporation
+ *  by Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/delay.h>
+#include <linux/fpga/altera-pr-ip-core.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/module.h>
+
+#define ALT_PR_DATA_OFST		0x00
+#define ALT_PR_CSR_OFST			0x04
+
+#define ALT_PR_CSR_PR_START		BIT(0)
+#define ALT_PR_CSR_STATUS_SFT		2
+#define ALT_PR_CSR_STATUS_MSK		(7 << ALT_PR_CSR_STATUS_SFT)
+#define ALT_PR_CSR_STATUS_NRESET	(0 << ALT_PR_CSR_STATUS_SFT)
+#define ALT_PR_CSR_STATUS_PR_ERR	(1 << ALT_PR_CSR_STATUS_SFT)
+#define ALT_PR_CSR_STATUS_CRC_ERR	(2 << ALT_PR_CSR_STATUS_SFT)
+#define ALT_PR_CSR_STATUS_BAD_BITS	(3 << ALT_PR_CSR_STATUS_SFT)
+#define ALT_PR_CSR_STATUS_PR_IN_PROG	(4 << ALT_PR_CSR_STATUS_SFT)
+#define ALT_PR_CSR_STATUS_PR_SUCCESS	(5 << ALT_PR_CSR_STATUS_SFT)
+
+struct alt_pr_priv {
+	void __iomem *reg_base;
+};
+
+static enum fpga_mgr_states alt_pr_fpga_state(struct fpga_manager *mgr)
+{
+	struct alt_pr_priv *priv = mgr->priv;
+	const char *err = "unknown";
+	enum fpga_mgr_states ret = FPGA_MGR_STATE_UNKNOWN;
+	u32 val;
+
+	val = readl(priv->reg_base + ALT_PR_CSR_OFST);
+
+	val &= ALT_PR_CSR_STATUS_MSK;
+
+	switch (val) {
+	case ALT_PR_CSR_STATUS_NRESET:
+		return FPGA_MGR_STATE_RESET;
+
+	case ALT_PR_CSR_STATUS_PR_ERR:
+		err = "pr error";
+		ret = FPGA_MGR_STATE_WRITE_ERR;
+		break;
+
+	case ALT_PR_CSR_STATUS_CRC_ERR:
+		err = "crc error";
+		ret = FPGA_MGR_STATE_WRITE_ERR;
+		break;
+
+	case ALT_PR_CSR_STATUS_BAD_BITS:
+		err = "bad bits";
+		ret = FPGA_MGR_STATE_WRITE_ERR;
+		break;
+
+	case ALT_PR_CSR_STATUS_PR_IN_PROG:
+		return FPGA_MGR_STATE_WRITE;
+
+	case ALT_PR_CSR_STATUS_PR_SUCCESS:
+		return FPGA_MGR_STATE_OPERATING;
+
+	default:
+		break;
+	}
+
+	dev_err(&mgr->dev, "encountered error code %d (%s) in %s()\n",
+		val, err, __func__);
+	return ret;
+}
+
+static int alt_pr_fpga_write_init(struct fpga_manager *mgr,
+				  struct fpga_image_info *info,
+				  const char *buf, size_t count)
+{
+	struct alt_pr_priv *priv = mgr->priv;
+	u32 val;
+
+	if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
+		dev_err(&mgr->dev, "%s Partial Reconfiguration flag not set\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	val = readl(priv->reg_base + ALT_PR_CSR_OFST);
+
+	if (val & ALT_PR_CSR_PR_START) {
+		dev_err(&mgr->dev,
+			"%s Partial Reconfiguration already started\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	writel(val | ALT_PR_CSR_PR_START, priv->reg_base + ALT_PR_CSR_OFST);
+
+	return 0;
+}
+
+static int alt_pr_fpga_write(struct fpga_manager *mgr, const char *buf,
+			     size_t count)
+{
+	struct alt_pr_priv *priv = mgr->priv;
+	u32 *buffer_32 = (u32 *)buf;
+	size_t i = 0;
+
+	if (count <= 0)
+		return -EINVAL;
+
+	/* Write out the complete 32-bit chunks */
+	while (count >= sizeof(u32)) {
+		writel(buffer_32[i++], priv->reg_base);
+		count -= sizeof(u32);
+	}
+
+	/* Write out remaining non 32-bit chunks */
+	switch (count) {
+	case 3:
+		writel(buffer_32[i++] & 0x00ffffff, priv->reg_base);
+		break;
+	case 2:
+		writel(buffer_32[i++] & 0x0000ffff, priv->reg_base);
+		break;
+	case 1:
+		writel(buffer_32[i++] & 0x000000ff, priv->reg_base);
+		break;
+	case 0:
+		break;
+	default:
+		/* This will never happen */
+		return -EFAULT;
+	}
+
+	if (alt_pr_fpga_state(mgr) == FPGA_MGR_STATE_WRITE_ERR)
+		return -EIO;
+
+	return 0;
+}
+
+static int alt_pr_fpga_write_complete(struct fpga_manager *mgr,
+				      struct fpga_image_info *info)
+{
+	u32 i = 0;
+
+	do {
+		switch (alt_pr_fpga_state(mgr)) {
+		case FPGA_MGR_STATE_WRITE_ERR:
+			return -EIO;
+
+		case FPGA_MGR_STATE_OPERATING:
+			dev_info(&mgr->dev,
+				 "successful partial reconfiguration\n");
+			return 0;
+
+		default:
+			break;
+		}
+		udelay(1);
+	} while (info->config_complete_timeout_us > i++);
+
+	dev_err(&mgr->dev, "timed out waiting for write to complete\n");
+	return -ETIMEDOUT;
+}
+
+static const struct fpga_manager_ops alt_pr_ops = {
+	.state = alt_pr_fpga_state,
+	.write_init = alt_pr_fpga_write_init,
+	.write = alt_pr_fpga_write,
+	.write_complete = alt_pr_fpga_write_complete,
+};
+
+int alt_pr_register(struct device *dev, void __iomem *reg_base)
+{
+	struct alt_pr_priv *priv;
+	u32 val;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->reg_base = reg_base;
+
+	val = readl(priv->reg_base + ALT_PR_CSR_OFST);
+
+	dev_dbg(dev, "%s status=%d start=%d\n", __func__,
+		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
+		(int)(val & ALT_PR_CSR_PR_START));
+
+	return fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
+}
+EXPORT_SYMBOL_GPL(alt_pr_register);
+
+int alt_pr_unregister(struct device *dev)
+{
+	dev_dbg(dev, "%s\n", __func__);
+
+	fpga_mgr_unregister(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(alt_pr_unregister);
+
+MODULE_AUTHOR("Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Altera Partial Reconfiguration IP Core");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/fpga/altera-pr-ip-core.h b/include/linux/fpga/altera-pr-ip-core.h
new file mode 100644
index 0000000..3810a90
--- /dev/null
+++ b/include/linux/fpga/altera-pr-ip-core.h
@@ -0,0 +1,29 @@
+/*
+ * Driver for Altera Partial Reconfiguration IP Core
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Based on socfpga-a10.c Copyright (C) 2015-2016 Altera Corporation
+ *  by Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _ALT_PR_IP_CORE_H
+#define _ALT_PR_IP_CORE_H
+#include <linux/io.h>
+
+int alt_pr_register(struct device *dev, void __iomem *reg_base);
+int alt_pr_unregister(struct device *dev);
+
+#endif /* _ALT_PR_IP_CORE_H */
-- 
2.7.4