[PATCH v3 1/2] ARM: zynq: Add OCM controller driver

* [PATCH v3 1/2] ARM: zynq: Add OCM controller driver
@ 2014-10-06 12:38 Michal Simek
  2014-10-06 12:38 ` [PATCH v3 2/2] ARM: zynq: DT: Add OCM controller node Michal Simek
  2014-10-06 16:04 ` [PATCH v3 1/2] ARM: zynq: Add OCM controller driver Sören Brinkmann
  0 siblings, 2 replies; 3+ messages in thread
From: Michal Simek @ 2014-10-06 12:38 UTC (permalink / raw)
  To: linux-arm-kernel, Soren Brinkmann, Olof Johansson
  Cc: monstr, Josh Cartwright, Steffen Trumtrar, Rob Herring,
	Peter Crosthwaite, Rob Herring, Pawel Moll, Mark Rutland,
	Ian Campbell, Kumar Gala, Grant Likely, Thierry Reding,
	Andy Gross, Stephen Warren, Peter De Schrijver, devicetree,
	linux-kernel

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The driver provide memory allocator which can
be used by others drivers to allocate memory inside OCM.
All location for 64kB blocks are supported
and driver is trying to allocate the largest continuous
block of memory.

Checking mpcore addressing filterring is not done here
but could be added in future.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

Changes in v3:
- Move OCM to drivers/soc
- Update year
- Extract DTS node to be able to apply it out of driver
- Remove generic allocator enabling
- Extract SLCR part
- Use const in of_device_id
- OCM->OCMC
- Use ocmc-1.0 compatible string

Changes in v2:
- Change compatibility string to be in xilinx format
- Fix kernel-doc format

For everybody on-chip SRAM driver "mmio-sram"
is missing parity IRQ handling not sure how to write
in generic way and also the memory layout
can be changed at run time (not currently supported by this driver)

smp-sram trampoline allocation can be used from mmio-sram
and size allocated via DT but currently no reason for using
it.

Creating mmio-sram node with setting at run time based on current setting
is possible but it won't look good.
One way how to do it is here
"ARM: mvebu: Add quirk for i2c for the OpenBlocks AX3-4 board"
(sha1: 85e618a1be2b2092318178d1d66bdad49cbbeeeb)
but creating nodes at run-time or changing compact strings
will be just more hacky code.

---
 .../bindings/arm/zynq/xlnx,zynq-ocmc.txt           |  17 ++
 drivers/soc/Makefile                               |   1 +
 drivers/soc/zynq/Makefile                          |   1 +
 drivers/soc/zynq/zynq_ocmc.c                       | 246 +++++++++++++++++++++
 4 files changed, 265 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/zynq/xlnx,zynq-ocmc.txt
 create mode 100644 drivers/soc/zynq/Makefile
 create mode 100644 drivers/soc/zynq/zynq_ocmc.c

diff --git a/Documentation/devicetree/bindings/arm/zynq/xlnx,zynq-ocmc.txt b/Documentation/devicetree/bindings/arm/zynq/xlnx,zynq-ocmc.txt
new file mode 100644
index 000000000000..8ddbd1e5ffc1
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/zynq/xlnx,zynq-ocmc.txt
@@ -0,0 +1,17 @@
+Device tree bindings for Zynq's OCM controller
+
+The OCM is divided to 4 64kB segments which can be separately configured
+to low or high location. Location is controlled via SLCR.
+
+Required properties:
+ compatible: Compatibility string. Must be "xlnx,zynq-ocmc-1.0".
+ reg: Specify the base and size of the OCMC registers in the memory map.
+      E.g.: reg = <0xf800c000 0x1000>;
+
+Example:
+ocmc: ocmc@f800c000 {
+	compatible =  "xlnx,zynq-ocmc-1.0";
+	interrupt-parent = <&intc>;
+	interrupts = <0 3 4>;
+	reg = <0xf800c000 0x1000>;
+} ;
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 3b1b95d932d1..dbe19f721701 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -4,3 +4,4 @@

 obj-$(CONFIG_ARCH_QCOM)		+= qcom/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
+obj-$(CONFIG_ARCH_ZYNQ)		+= zynq/
diff --git a/drivers/soc/zynq/Makefile b/drivers/soc/zynq/Makefile
new file mode 100644
index 000000000000..7c6a5612ee66
--- /dev/null
+++ b/drivers/soc/zynq/Makefile
@@ -0,0 +1 @@
+obj-y += zynq_ocmc.o
diff --git a/drivers/soc/zynq/zynq_ocmc.c b/drivers/soc/zynq/zynq_ocmc.c
new file mode 100644
index 000000000000..0ad8ad67797b
--- /dev/null
+++ b/drivers/soc/zynq/zynq_ocmc.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) 2013 - 2014 Xilinx
+ *
+ * Based on "Generic on-chip SRAM allocation driver"
+ *
+ * Copyright (C) 2012 Philipp Zabel, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/genalloc.h>
+
+#include <soc/zynq/common.h>
+
+#define ZYNQ_OCMC_HIGHADDR	0xfffc0000
+#define ZYNQ_OCMC_LOWADDR	0x0
+#define ZYNQ_OCMC_BLOCK_SIZE	0x10000
+#define ZYNQ_OCMC_BLOCKS		4
+#define ZYNQ_OCMC_GRANULARITY	32
+
+#define ZYNQ_OCMC_PARITY_CTRL	0x0
+#define ZYNQ_OCMC_PARITY_ENABLE	0x1e
+
+#define ZYNQ_OCMC_PARITY_ERRADDRESS	0x4
+
+#define ZYNQ_OCMC_IRQ_STS		0x8
+#define ZYNQ_OCMC_IRQ_STS_ERR_MASK	0x7
+
+struct zynq_ocmc_dev {
+	void __iomem *base;
+	int irq;
+	struct gen_pool *pool;
+	struct resource res[ZYNQ_OCMC_BLOCKS];
+};
+
+/**
+ * zynq_ocmc_irq_handler - Interrupt service routine of the OCM controller
+ * @irq:	IRQ number
+ * @data:	Pointer to the zynq_ocmc_dev structure
+ *
+ * Return:     IRQ_HANDLED always
+ */
+static irqreturn_t zynq_ocmc_irq_handler(int irq, void *data)
+{
+	u32 sts;
+	u32 err_addr;
+	struct zynq_ocmc_dev *zynq_ocmc = data;
+
+	/* check status */
+	sts = readl(zynq_ocmc->base + ZYNQ_OCMC_IRQ_STS);
+	if (sts & ZYNQ_OCMC_IRQ_STS_ERR_MASK) {
+		/* check error address */
+		err_addr = readl(zynq_ocmc->base + ZYNQ_OCMC_PARITY_ERRADDRESS);
+		pr_err("%s: OCM err intr generated at 0x%04x (stat: 0x%08x).",
+		       __func__, err_addr, sts & ZYNQ_OCMC_IRQ_STS_ERR_MASK);
+	}
+	pr_warn("%s: Interrupt generated by OCM, but no error is found.",
+		__func__);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * zynq_ocmc_probe - Probe method for the OCM driver
+ * @pdev:	Pointer to the platform_device structure
+ *
+ * This function initializes the driver data structures and the hardware.
+ *
+ * Return:	0 on success and error value on failure
+ */
+static int zynq_ocmc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct zynq_ocmc_dev *zynq_ocmc;
+	u32 i, ocm_config, curr;
+	struct resource *res;
+
+	ocm_config = zynq_slcr_get_ocm_config();
+
+	zynq_ocmc = devm_kzalloc(&pdev->dev, sizeof(*zynq_ocmc), GFP_KERNEL);
+	if (!zynq_ocmc)
+		return -ENOMEM;
+
+	zynq_ocmc->pool = devm_gen_pool_create(&pdev->dev,
+					       ilog2(ZYNQ_OCMC_GRANULARITY),
+					       -1);
+	if (!zynq_ocmc->pool)
+		return -ENOMEM;
+
+	curr = 0; /* For storing current struct resource for OCM */
+	for (i = 0; i < ZYNQ_OCMC_BLOCKS; i++) {
+		u32 base, start, end;
+
+		/* Setup base address for 64kB OCM block */
+		if (ocm_config & BIT(i))
+			base = ZYNQ_OCMC_HIGHADDR;
+		else
+			base = ZYNQ_OCMC_LOWADDR;
+
+		/* Calculate start and end block addresses */
+		start = i * ZYNQ_OCMC_BLOCK_SIZE + base;
+		end = start + (ZYNQ_OCMC_BLOCK_SIZE - 1);
+
+		/* Concatenate OCM blocks together to get bigger pool */
+		if (i > 0 && start == (zynq_ocmc->res[curr - 1].end + 1)) {
+			zynq_ocmc->res[curr - 1].end = end;
+		} else {
+#ifdef CONFIG_SMP
+			/*
+			 * OCM block if placed at 0x0 has special meaning
+			 * for SMP because jump trampoline is added there.
+			 * Ensure that this address won't be allocated.
+			 */
+			if (!base) {
+				u32 trampoline_code_size =
+					&zynq_secondary_trampoline_end -
+					&zynq_secondary_trampoline;
+				dev_dbg(&pdev->dev,
+					"Allocate reset vector table %dB\n",
+					trampoline_code_size);
+				/* Postpone start offset */
+				start += trampoline_code_size;
+			}
+#endif
+			/* First resource is always initialized */
+			zynq_ocmc->res[curr].start = start;
+			zynq_ocmc->res[curr].end = end;
+			zynq_ocmc->res[curr].flags = IORESOURCE_MEM;
+			curr++; /* Increment curr value */
+		}
+		dev_dbg(&pdev->dev, "OCM block %d, start %x, end %x\n",
+			i, start, end);
+	}
+
+	/*
+	 * Separate pool allocation from OCM block detection to ensure
+	 * the biggest possible pool.
+	 */
+	for (i = 0; i < ZYNQ_OCMC_BLOCKS; i++) {
+		unsigned long size;
+		void __iomem *virt_base;
+
+		/* Skip all zero size resources */
+		if (zynq_ocmc->res[i].end == 0)
+			break;
+		dev_dbg(&pdev->dev, "OCM resources %d, start %x, end %x\n",
+			i, zynq_ocmc->res[i].start, zynq_ocmc->res[i].end);
+		size = resource_size(&zynq_ocmc->res[i]);
+		virt_base = devm_ioremap_resource(&pdev->dev,
+						  &zynq_ocmc->res[i]);
+		if (IS_ERR(virt_base))
+			return PTR_ERR(virt_base);
+
+		ret = gen_pool_add_virt(zynq_ocmc->pool,
+					(unsigned long)virt_base,
+					zynq_ocmc->res[i].start, size, -1);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "Gen pool failed\n");
+			return ret;
+		}
+		dev_info(&pdev->dev, "ZYNQ OCM pool: %ld KiB @ 0x%p\n",
+			 size / 1024, virt_base);
+	}
+
+	/* Get OCM config space */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	zynq_ocmc->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(zynq_ocmc->base))
+		return PTR_ERR(zynq_ocmc->base);
+
+	/* Allocate OCM parity IRQ */
+	zynq_ocmc->irq = platform_get_irq(pdev, 0);
+	if (zynq_ocmc->irq < 0) {
+		dev_err(&pdev->dev, "irq resource not found\n");
+		return zynq_ocmc->irq;
+	}
+	ret = devm_request_irq(&pdev->dev, zynq_ocmc->irq,
+			       zynq_ocmc_irq_handler,
+			       0, pdev->name, zynq_ocmc);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "request_irq failed\n");
+		return ret;
+	}
+
+	/* Enable parity errors */
+	writel(ZYNQ_OCMC_PARITY_ENABLE,
+	       zynq_ocmc->base + ZYNQ_OCMC_PARITY_CTRL);
+
+	platform_set_drvdata(pdev, zynq_ocmc);
+
+	return 0;
+}
+
+/**
+ * zynq_ocmc_remove - Remove method for the OCM driver
+ * @pdev:	Pointer to the platform_device structure
+ *
+ * Return:	0 on success and error value on failure
+ *
+ * This function is called if a device is physically removed from the system or
+ * if the driver module is being unloaded. It frees all resources allocated to
+ * the device.
+ */
+static int zynq_ocmc_remove(struct platform_device *pdev)
+{
+	struct zynq_ocmc_dev *zynq_ocmc = platform_get_drvdata(pdev);
+
+	if (gen_pool_avail(zynq_ocmc->pool) < gen_pool_size(zynq_ocmc->pool))
+		dev_dbg(&pdev->dev, "removed while SRAM allocated\n");
+
+	return 0;
+}
+
+static const struct of_device_id zynq_ocmc_dt_ids[] = {
+	{ .compatible = "xlnx,zynq-ocmc-1.0" },
+	{ /* end of table */ }
+};
+
+static struct platform_driver zynq_ocmc_driver = {
+	.driver = {
+		.name = "zynq_ocmc",
+		.of_match_table = zynq_ocmc_dt_ids,
+	},
+	.probe = zynq_ocmc_probe,
+	.remove = zynq_ocmc_remove,
+};
+
+static int __init zynq_ocmc_init(void)
+{
+	return platform_driver_register(&zynq_ocmc_driver);
+}
+
+arch_initcall(zynq_ocmc_init);
--
1.8.2.3


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