[PATCH v6 0/5] Device Bus support for Marvell EBU SoC

[PATCH v6 0/5] Device Bus support for Marvell EBU SoC

[Ezequiel Garcia]

This patchset continues the effort to add Device Bus support
on Marvell EBU SoC.

If you're reading this for the first time you can grab the full details here:

  http://www.spinics.net/lists/arm-kernel/msg236151.html

This new version changes the way each chip select is described in the DT.
Now there's a separate node for each Device Bus chip select, like this:

	devbus-bootcs at d0010400 {
		compatible = "marvell,mvebu-devbus";
		reg = <0xd0010400 0x8>;
		ranges = <0 0xf0000000 0x8000000>; /* @addr 0xf000000, size 0x8000000 */

		device at 0 {
			reg = <0 0x8000000>;
		}
	};

	// ...

	devbus-cs1 at d0010410 {
		compatible = "marvell,mvebu-devbus";
		reg = <0xd0010410 0x8>;
	};

In particular, please note that once the window handling is properly added
to the DT, and we remove the mbus usage from this driver, in the above DT nodes
the ranges property value will have to be changed, but the ABI will be the same.

This applies on top of v3.9-rc5 with mbus patches applied, which can 
be found in Jason Cooper's mvebus/soc branch.

This v6 fixes some issues pointed out by both Arnd Bergmann and Jason Gunthorpe.
Thanks to both for reviewing the driver and for the feedback!

Changes from v5:

  * Instead of translating the child address, parse the 'ranges'
    property. This is possible because the 'ranges' is mandatory
    and will a single entry to describing the address window.
    This allows to remove every reference to child nodes, and will
    be removed later, once the mbus binding is added.

  * Use of_platform_populate to register all child nodes.
    This way we solve the one-child only constraint present
    in the previous v5 of this series.

  * Rework the driver registration. Now there's a module_init()
    to register the platform driver, but there's no module_exit()
    to unregister it. This is done because currently there's no
    function opposite to of_platform_populate() to unregister all
    devices from a DT tree.

Changes from v4:

  * Calculate the chip select from the base address
    and drop the 2-cell address size.
    Suggested by Arnd Bergmann and Jason Gunthorpe.

  * The mvebu driver can't be compiled as a module, since the mbus
    API is not exported yet, so remove that option.

  * Bunch of comments here and there...

Changes from v3:

  * Rename devbus,dev-width to devbus,bus-width and changed the
    parameter value from bytes to bits: <8>, <16>, ...
    Suggested by Arnd Bergmann.

  * As suggested by Jason Gunthorpe and agreed by Arnd Bergmann.
    Reworked the whole devbus child chip-select device tree design.
    Now there's a separate devbus at addr DT node for each controller
    chip select. The impact of this is:
      1. Timing parameters now go into the parent node.
      2. There can only be one child per devbus node.

  * Remove unneeded bank-width parameter read.

Changes from v2:

  * Replace the 'NOR' specific probe by a generic probe.
    Currently, we don't see anything specific to NOR in this driver.
    Suggested by Jason Gunthorpe.

  * Add a check to detect that every timing parameter is specified
    in the device tree node.
    Suggested by Jason Gunthorpe.

Changes from v1:

  * Added a remove() function to unregister childs and remove address windows,
    as suggested by Thomas Petazzoni.

  * Remove unneeded 'inline' prefix on functions as suggested by Thomas Petazzoni.

  * Timings parameters are now mandatory and expressed in picoseconds,
    as requested by Jason Gunthorpe.
    This is consistent with OMAP's GPMC dts binding.

  * Fix documentation as suggested by Jason Gunthorpe.

Thanks!

Ezequiel Garcia (5):
  drivers: memory: Introduce Marvell EBU Device Bus driver
  ARM: mvebu: Add Device Bus support for Armada 370/XP SoC
  ARM: mvebu: Add support for NOR flash device on Armada XP-GP board
  ARM: mvebu: Add support for NOR flash device on Openblocks AX3 board
  ARM: mvebu: Add Device Bus and CFI flash memory support to defconfig

 .../bindings/memory-controllers/mvebu-devbus.txt   | 156 ++++++++++
 arch/arm/boot/dts/armada-370-xp.dtsi               |  45 +++
 arch/arm/boot/dts/armada-xp-gp.dts                 |  29 ++
 arch/arm/boot/dts/armada-xp-openblocks-ax3-4.dts   |  29 ++
 arch/arm/configs/mvebu_defconfig                   |   7 +
 drivers/memory/Kconfig                             |  10 +
 drivers/memory/Makefile                            |   1 +
 drivers/memory/mvebu-devbus.c                      | 326 +++++++++++++++++++++
 8 files changed, 603 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt
 create mode 100644 drivers/memory/mvebu-devbus.c

-- 
1.8.1.5

[PATCH v6 1/5] drivers: memory: Introduce Marvell EBU Device Bus driver

[Ezequiel Garcia]

Marvell EBU SoCs such as Armada 370/XP, Orion5x (88f5xxx) and
Discovery (mv78xx0) supports a Device Bus controller to access several
kinds of memories and I/O devices (NOR, NAND, SRAM, FPGA).

This commit adds a driver to handle this controller. So far only
Armada 370, Armada XP and Discovery SoCs are supported.

The driver must be registered through a device tree node;
as explained in the binding document.

For each child node in the device tree, this driver will:
  * set timing parameters
  * register a child device
  * setup an address decoding window, using the mbus driver

Keep in mind the address decoding window setup is only a temporary hack.
This code will be removed from this devbus driver as soon as a proper device
tree binding for the mbus driver is added.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 .../bindings/memory-controllers/mvebu-devbus.txt   | 156 ++++++++++
 drivers/memory/Kconfig                             |  10 +
 drivers/memory/Makefile                            |   1 +
 drivers/memory/mvebu-devbus.c                      | 326 +++++++++++++++++++++
 4 files changed, 493 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt
 create mode 100644 drivers/memory/mvebu-devbus.c

diff --git a/Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt b/Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt
new file mode 100644
index 0000000..653c90c
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt
@@ -0,0 +1,156 @@
+Device tree bindings for MVEBU Device Bus controllers
+
+The Device Bus controller available in some Marvell's SoC allows to control
+different types of standard memory and I/O devices such as NOR, NAND, and FPGA.
+The actual devices are instantiated from the child nodes of a Device Bus node.
+
+Required properties:
+
+ - compatible:          Currently only Armada 370/XP SoC are supported,
+                        with this compatible string:
+
+                        marvell,mvebu-devbus
+
+ - reg:                 A resource specifier for the register space.
+                        This is the base address of a chip select within
+			the controller's register space.
+                        (see the example below)
+
+ - #address-cells:      Must be set to 1
+ - #size-cells:         Must be set to 1
+ - ranges:              Must be set up to reflect the memory layout with four
+                        integer values for each chip-select line in use:
+                        0 <physical address of mapping> <size>
+
+Mandatory timing properties for child nodes:
+
+Read parameters:
+
+ - devbus,turn-off-ps:  Defines the time during which the controller does not
+                        drive the AD bus after the completion of a device read.
+                        This prevents contentions on the Device Bus after a read
+                        cycle from a slow device.
+
+ - devbus,bus-width:    Defines the bus width (e.g. <16>)
+
+ - devbus,badr-skew-ps: Defines the time delay from from A[2:0] toggle,
+                        to read data sample. This parameter is useful for
+                        synchronous pipelined devices, where the address
+                        precedes the read data by one or two cycles.
+
+ - devbus,acc-first-ps: Defines the time delay from the negation of
+                        ALE[0] to the cycle that the first read data is sampled
+                        by the controller.
+
+ - devbus,acc-next-ps:  Defines the time delay between the cycle that
+                        samples data N and the cycle that samples data N+1
+                        (in burst accesses).
+
+ - devbus,rd-setup-ps:  Defines the time delay between DEV_CSn assertion to
+			DEV_OEn assertion. If set to 0 (default),
+                        DEV_OEn and DEV_CSn are asserted at the same cycle.
+                        This parameter has no affect on <acc-first-ps> parameter
+                        (no affect on first data sample). Set <rd-setup-ps>
+                        to a value smaller than <acc-first-ps>.
+
+ - devbus,rd-hold-ps:   Defines the time between the last data sample to the
+			de-assertion of DEV_CSn. If set to 0 (default),
+			DEV_OEn and DEV_CSn are de-asserted at the same cycle
+			(the cycle of the last data sample).
+                        This parameter has no affect on DEV_OEn de-assertion.
+                        DEV_OEn is always de-asserted the next cycle after
+                        last data sampled. Also this parameter has no
+                        affect on <turn-off-ps> parameter.
+                        Set <rd-hold-ps> to a value smaller than <turn-off-ps>.
+
+Write parameters:
+
+ - devbus,ale-wr-ps:    Defines the time delay from the ALE[0] negation cycle
+			to the DEV_WEn assertion.
+
+ - devbus,wr-low-ps:    Defines the time during which DEV_WEn is active.
+                        A[2:0] and Data are kept valid as long as DEV_WEn
+                        is active. This parameter defines the setup time of
+                        address and data to DEV_WEn rise.
+
+ - devbus,wr-high-ps:   Defines the time during which DEV_WEn is kept
+                        inactive (high) between data beats of a burst write.
+                        DEV_A[2:0] and Data are kept valid (do not toggle) for
+                        <wr-high-ps> - <tick> ps.
+			This parameter defines the hold time of address and
+			data after DEV_WEn rise.
+
+ - devbus,sync-enable: Synchronous device enable.
+                       1: True
+                       0: False
+
+An example for an Armada XP GP board, with a 16 MiB NOR device as child
+is showed below. Note that the Device Bus driver is in charge of allocating
+the mbus address decoding window for each of its child devices.
+The window is created using the chip select specified in the child
+device node together with the base address and size specified in the ranges
+property. For instance, in the example below the allocated decoding window
+will start at base address 0xf0000000, with a size 0x1000000 (16 MiB)
+for chip select 0 (a.k.a DEV_BOOTCS).
+
+This address window handling is done in this mvebu-devbus only as a temporary
+solution. It will be removed when the support for mbus device tree binding is
+added.
+
+The reg property implicitly specifies the chip select as this:
+
+  0x10400: DEV_BOOTCS
+  0x10408: DEV_CS0
+  0x10410: DEV_CS1
+  0x10418: DEV_CS2
+  0x10420: DEV_CS3
+
+Example:
+
+	devbus-bootcs at d0010400 {
+		status = "okay";
+		ranges = <0 0xf0000000 0x1000000>; /* @addr 0xf0000000, size 0x1000000 */
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/* Device Bus parameters are required */
+
+		/* Read parameters */
+		devbus,bus-width    = <8>;
+		devbus,turn-off-ps  = <60000>;
+		devbus,badr-skew-ps = <0>;
+		devbus,acc-first-ps = <124000>;
+		devbus,acc-next-ps  = <248000>;
+		devbus,rd-setup-ps  = <0>;
+		devbus,rd-hold-ps   = <0>;
+
+		/* Write parameters */
+		devbus,sync-enable = <0>;
+		devbus,wr-high-ps  = <60000>;
+		devbus,wr-low-ps   = <60000>;
+		devbus,ale-wr-ps   = <60000>;
+
+		flash at 0 {
+			compatible = "cfi-flash";
+
+			/* 16 MiB */
+			reg = <0 0x1000000>;
+			bank-width = <2>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			/*
+			 * We split the 16 MiB in two partitions,
+			 * just as an example.
+			 */
+			partition at 0 {
+				label = "First";
+				reg = <0 0x800000>;
+			};
+
+			partition at 800000 {
+				label = "Second";
+				reg = <0x800000 0x800000>;
+			};
+		};
+	};
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 067f311..29a11db 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -20,6 +20,16 @@ config TI_EMIF
 	  parameters and other settings during frequency, voltage and
 	  temperature changes
 
+config MVEBU_DEVBUS
+	bool "Marvell EBU Device Bus Controller"
+	default y
+	depends on PLAT_ORION && OF
+	help
+	  This driver is for the Device Bus controller available in some
+	  Marvell EBU SoCs such as Discovery (mv78xx0), Orion (88f5xxx) and
+	  Armada 370 and Armada XP. This controller allows to handle flash
+	  devices such as NOR, NAND, SRAM, and FPGA.
+
 config TEGRA20_MC
 	bool "Tegra20 Memory Controller(MC) driver"
 	default y
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 9cce5d7..969d923 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -6,5 +6,6 @@ ifeq ($(CONFIG_DDR),y)
 obj-$(CONFIG_OF)		+= of_memory.o
 endif
 obj-$(CONFIG_TI_EMIF)		+= emif.o
+obj-$(CONFIG_MVEBU_DEVBUS)	+= mvebu-devbus.o
 obj-$(CONFIG_TEGRA20_MC)	+= tegra20-mc.o
 obj-$(CONFIG_TEGRA30_MC)	+= tegra30-mc.o
diff --git a/drivers/memory/mvebu-devbus.c b/drivers/memory/mvebu-devbus.c
new file mode 100644
index 0000000..d4284d4
--- /dev/null
+++ b/drivers/memory/mvebu-devbus.c
@@ -0,0 +1,326 @@
+/*
+ * Marvell EBU SoC Device Bus Controller
+ * (memory controller for NOR/NAND/SRAM/FPGA devices)
+ *
+ * Copyright (C) 2013 Marvell
+ *
+ * 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 version 2 of the License.
+ *
+ * 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.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/mbus.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+/* Register definitions */
+#define DEV_WIDTH_BIT		30
+#define BADR_SKEW_BIT		28
+#define RD_HOLD_BIT		23
+#define ACC_NEXT_BIT		17
+#define RD_SETUP_BIT		12
+#define ACC_FIRST_BIT		6
+
+#define SYNC_ENABLE_BIT		24
+#define WR_HIGH_BIT		16
+#define WR_LOW_BIT		8
+
+#define READ_PARAM_OFFSET	0x0
+#define WRITE_PARAM_OFFSET	0x4
+
+static const char * const devbus_wins[] = {
+	"devbus-boot",
+	"devbus-cs0",
+	"devbus-cs1",
+	"devbus-cs2",
+	"devbus-cs3",
+};
+
+struct devbus_read_params {
+	u32 bus_width;
+	u32 badr_skew;
+	u32 turn_off;
+	u32 acc_first;
+	u32 acc_next;
+	u32 rd_setup;
+	u32 rd_hold;
+};
+
+struct devbus_write_params {
+	u32 sync_enable;
+	u32 wr_high;
+	u32 wr_low;
+	u32 ale_wr;
+};
+
+struct devbus {
+	struct device *dev;
+	void __iomem *base;
+	unsigned long tick_ps;
+};
+
+static int get_timing_param_ps(struct devbus *devbus,
+			       struct device_node *node,
+			       const char *name,
+			       u32 *ticks)
+{
+	u32 time_ps;
+	int err;
+
+	err = of_property_read_u32(node, name, &time_ps);
+	if (err < 0) {
+		dev_err(devbus->dev, "%s has no '%s' property\n",
+			name, node->full_name);
+		return err;
+	}
+
+	*ticks = (time_ps + devbus->tick_ps - 1) / devbus->tick_ps;
+
+	dev_dbg(devbus->dev, "%s: %u ps -> 0x%x\n",
+		name, time_ps, *ticks);
+	return 0;
+}
+
+static int devbus_set_timing_params(struct devbus *devbus,
+				    struct device_node *node)
+{
+	struct devbus_read_params r;
+	struct devbus_write_params w;
+	u32 value;
+	int err;
+
+	dev_dbg(devbus->dev, "Setting timing parameter, tick is %lu ps\n",
+		devbus->tick_ps);
+
+	/* Get read timings */
+	err = of_property_read_u32(node, "devbus,bus-width", &r.bus_width);
+	if (err < 0) {
+		dev_err(devbus->dev,
+			"%s has no 'devbus,bus-width' property\n",
+			node->full_name);
+		return err;
+	}
+	/* Convert bit width to byte width */
+	r.bus_width /= 8;
+
+	err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps",
+				 &r.badr_skew);
+	if (err < 0)
+		return err;
+
+	err = get_timing_param_ps(devbus, node, "devbus,turn-off-ps",
+				 &r.turn_off);
+	if (err < 0)
+		return err;
+
+	err = get_timing_param_ps(devbus, node, "devbus,acc-first-ps",
+				 &r.acc_first);
+	if (err < 0)
+		return err;
+
+	err = get_timing_param_ps(devbus, node, "devbus,acc-next-ps",
+				 &r.acc_next);
+	if (err < 0)
+		return err;
+
+	err = get_timing_param_ps(devbus, node, "devbus,rd-setup-ps",
+				 &r.rd_setup);
+	if (err < 0)
+		return err;
+
+	err = get_timing_param_ps(devbus, node, "devbus,rd-hold-ps",
+				 &r.rd_hold);
+	if (err < 0)
+		return err;
+
+	/* Get write timings */
+	err = of_property_read_u32(node, "devbus,sync-enable",
+				  &w.sync_enable);
+	if (err < 0) {
+		dev_err(devbus->dev,
+			"%s has no 'devbus,sync-enable' property\n",
+			node->full_name);
+		return err;
+	}
+
+	err = get_timing_param_ps(devbus, node, "devbus,ale-wr-ps",
+				 &w.ale_wr);
+	if (err < 0)
+		return err;
+
+	err = get_timing_param_ps(devbus, node, "devbus,wr-low-ps",
+				 &w.wr_low);
+	if (err < 0)
+		return err;
+
+	err = get_timing_param_ps(devbus, node, "devbus,wr-high-ps",
+				 &w.wr_high);
+	if (err < 0)
+		return err;
+
+	/* Set read timings */
+	value = r.bus_width << DEV_WIDTH_BIT |
+		r.badr_skew << BADR_SKEW_BIT |
+		r.rd_hold   << RD_HOLD_BIT   |
+		r.acc_next  << ACC_NEXT_BIT  |
+		r.rd_setup  << RD_SETUP_BIT  |
+		r.acc_first << ACC_FIRST_BIT |
+		r.turn_off;
+
+	dev_dbg(devbus->dev, "read parameters register 0x%p = 0x%x\n",
+		devbus->base + READ_PARAM_OFFSET,
+		value);
+
+	writel(value, devbus->base + READ_PARAM_OFFSET);
+
+	/* Set write timings */
+	value = w.sync_enable  << SYNC_ENABLE_BIT |
+		w.wr_low       << WR_LOW_BIT      |
+		w.wr_high      << WR_HIGH_BIT     |
+		w.ale_wr;
+
+	dev_dbg(devbus->dev, "write parameters register: 0x%p = 0x%x\n",
+		devbus->base + WRITE_PARAM_OFFSET,
+		value);
+
+	writel(value, devbus->base + WRITE_PARAM_OFFSET);
+
+	return 0;
+}
+
+static int mvebu_devbus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = pdev->dev.of_node;
+	struct devbus *devbus;
+	struct resource *res;
+	struct clk *clk;
+	unsigned long rate;
+	int err, cs;
+	u32 addr_region[3];
+
+	devbus = devm_kzalloc(&pdev->dev, sizeof(struct devbus), GFP_KERNEL);
+	if (!devbus)
+		return -ENOMEM;
+
+	devbus->dev = dev;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	devbus->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(devbus->base))
+		return PTR_ERR(devbus->base);
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+	clk_prepare_enable(clk);
+
+	/*
+	 * Obtain clock period in picoseconds,
+	 * we need this in order to convert timing
+	 * parameters from cycles to picoseconds.
+	 */
+	rate = clk_get_rate(clk) / 1000;
+	devbus->tick_ps = 1000000000 / rate;
+
+	/* Read the device tree node and set the new timing parameters */
+	err = devbus_set_timing_params(devbus, node);
+	if (err < 0)
+		return err;
+
+	/*
+	 * Allocate an address window for this device.
+	 * If the device probing fails, then we won't be able to
+	 * remove the allocated address decoding window.
+	 *
+	 * FIXME: This is only a temporary hack! We need to do this here
+	 * because we still don't have device tree bindings for mbus.
+	 * Once that support is added, we will declare these address windows
+	 * statically in the device tree, and remove the window configuration
+	 * from here.
+	 */
+
+	/*
+	 * Get the CS to choose the window string.
+	 * This is a bit hacky, but it will be removed once the
+	 * address windows are declared in the device tree.
+	 */
+	cs = (((unsigned long)devbus->base) % 0x400) / 8;
+
+	/*
+	 * Since this is only part of the workaround,
+	 * we can do this dirty 'ranges' property parsing.
+	 * Of course, this will be removed once the address windows
+	 * are declared in the device tree.
+	 */
+	err = of_property_read_u32_array(node, "ranges", addr_region,
+					 ARRAY_SIZE(addr_region));
+	if (err < 0) {
+		dev_err(dev, "%s has a malformed 'range' property\n",
+			node->full_name);
+		return err;
+	}
+
+	/*
+	 * Create an mbus address windows.
+	 * FIXME: Remove this, together with the above code, once the
+	 * address windows are declared in the device tree.
+	 */
+	err = mvebu_mbus_add_window(devbus_wins[cs],
+				    addr_region[1], addr_region[2]);
+	if (err < 0)
+		return err;
+
+	/*
+	 * We need to create a child device explicitly from here to
+	 * guarantee that the child will be probed after the timing
+	 * parameters for the bus are written.
+	 */
+	err = of_platform_populate(node, NULL, NULL, dev);
+	if (err < 0) {
+		mvebu_mbus_del_window(addr_region[1], addr_region[2]);
+		return err;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id mvebu_devbus_of_match[] = {
+	{ .compatible = "marvell,mvebu-devbus" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mvebu_devbus_of_match);
+
+static struct platform_driver mvebu_devbus_driver = {
+	.probe		= mvebu_devbus_probe,
+	.driver		= {
+		.name	= "mvebu-devbus",
+		.owner	= THIS_MODULE,
+		.of_match_table = mvebu_devbus_of_match,
+	},
+};
+
+static int __init mvebu_devbus_init(void)
+{
+	return platform_driver_register(&mvebu_devbus_driver);
+}
+module_init(mvebu_devbus_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell EBU SoC Device Bus controller");
-- 
1.8.1.5

[PATCH v6 2/5] ARM: mvebu: Add Device Bus support for Armada 370/XP SoC

[Ezequiel Garcia]

Armada 370 and Armada XP SoC have a Device Bus controller to
handle NOR, NAND, SRAM and FPGA devices.
This patch adds the device tree node to enable the controller.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/boot/dts/armada-370-xp.dtsi | 45 ++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi
index 7704829..9693f79 100644
--- a/arch/arm/boot/dts/armada-370-xp.dtsi
+++ b/arch/arm/boot/dts/armada-370-xp.dtsi
@@ -176,6 +176,51 @@
 			clocks = <&coreclk 0>;
 			status = "disabled";
 		};
+
+		devbus-bootcs at d0010400 {
+			compatible = "marvell,mvebu-devbus";
+			reg = <0xd0010400 0x8>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			clocks = <&coreclk 0>;
+			status = "disabled";
+		};
+
+		devbus-cs0 at d0010408 {
+			compatible = "marvell,mvebu-devbus";
+			reg = <0xd0010408 0x8>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			clocks = <&coreclk 0>;
+			status = "disabled";
+		};
+
+		devbus-cs1 at d0010410 {
+			compatible = "marvell,mvebu-devbus";
+			reg = <0xd0010410 0x8>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			clocks = <&coreclk 0>;
+			status = "disabled";
+		};
+
+		devbus-cs2 at d0010418 {
+			compatible = "marvell,mvebu-devbus";
+			reg = <0xd0010418 0x8>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			clocks = <&coreclk 0>;
+			status = "disabled";
+		};
+
+		devbus-cs3 at d0010420 {
+			compatible = "marvell,mvebu-devbus";
+			reg = <0xd0010420 0x8>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			clocks = <&coreclk 0>;
+			status = "disabled";
+		};
 	};
 };
 
-- 
1.8.1.5

[PATCH v6 3/5] ARM: mvebu: Add support for NOR flash device on Armada XP-GP board

[Ezequiel Garcia]

The Armada XP Development Board DB-MV784MP-GP has a NOR flash device
connected to the Device Bus. This commit adds the device tree node
to support this device.

This SoC supports a flexible and dynamic decoding window allocation
scheme; but since this feature is still not implemented we need
to specify the window base address in the device tree node itself.

This base address has been selected in a completely arbitrary fashion.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/boot/dts/armada-xp-gp.dts | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/arch/arm/boot/dts/armada-xp-gp.dts b/arch/arm/boot/dts/armada-xp-gp.dts
index 1c8afe2..e57e9c7 100644
--- a/arch/arm/boot/dts/armada-xp-gp.dts
+++ b/arch/arm/boot/dts/armada-xp-gp.dts
@@ -109,5 +109,34 @@
 				spi-max-frequency = <108000000>;
 			};
 		};
+
+		devbus-bootcs at d0010400 {
+			status = "okay";
+			ranges = <0 0xf0000000 0x1000000>; /* @addr 0xf000000, size 0x1000000 */
+
+			/* Device Bus parameters are required */
+
+			/* Read parameters */
+			devbus,bus-width    = <8>;
+			devbus,turn-off-ps  = <60000>;
+			devbus,badr-skew-ps = <0>;
+			devbus,acc-first-ps = <124000>;
+			devbus,acc-next-ps  = <248000>;
+			devbus,rd-setup-ps  = <0>;
+			devbus,rd-hold-ps   = <0>;
+
+			/* Write parameters */
+			devbus,sync-enable = <0>;
+			devbus,wr-high-ps  = <60000>;
+			devbus,wr-low-ps   = <60000>;
+			devbus,ale-wr-ps   = <60000>;
+
+			/* NOR 16 MiB */
+			nor at 0 {
+				compatible = "cfi-flash";
+				reg = <0 0x1000000>;
+				bank-width = <2>;
+			};
+		};
 	};
 };
-- 
1.8.1.5

[PATCH v6 4/5] ARM: mvebu: Add support for NOR flash device on Openblocks AX3 board

[Ezequiel Garcia]

The Plat'home Openblocks AX3 has a 128 MiB NOR flash device connected
to the Device Bus. This commit adds the device tree node to support this device.

The SoC supports a flexible and dynamic decoding window allocation scheme;
but since this feature is still not implemented we need to specify the window
base address in the device tree node itself.
This base address has been selected in a completely arbitrary fashion.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/boot/dts/armada-xp-openblocks-ax3-4.dts | 29 ++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/arch/arm/boot/dts/armada-xp-openblocks-ax3-4.dts b/arch/arm/boot/dts/armada-xp-openblocks-ax3-4.dts
index 3818a82..b5c5f4d 100644
--- a/arch/arm/boot/dts/armada-xp-openblocks-ax3-4.dts
+++ b/arch/arm/boot/dts/armada-xp-openblocks-ax3-4.dts
@@ -139,5 +139,34 @@
 		usb at d0051000 {
 			status = "okay";
 		};
+
+		devbus-bootcs at d0010400 {
+			status = "okay";
+			ranges = <0 0xf0000000 0x8000000>; /* @addr 0xf000000, size 0x8000000 */
+
+			/* Device Bus parameters are required */
+
+			/* Read parameters */
+			devbus,bus-width    = <8>;
+			devbus,turn-off-ps  = <60000>;
+			devbus,badr-skew-ps = <0>;
+			devbus,acc-first-ps = <124000>;
+			devbus,acc-next-ps  = <248000>;
+			devbus,rd-setup-ps  = <0>;
+			devbus,rd-hold-ps   = <0>;
+
+			/* Write parameters */
+			devbus,sync-enable = <0>;
+			devbus,wr-high-ps  = <60000>;
+			devbus,wr-low-ps   = <60000>;
+			devbus,ale-wr-ps   = <60000>;
+
+			/* NOR 128 MiB */
+			nor at 0 {
+				compatible = "cfi-flash";
+				reg = <0 0x8000000>;
+				bank-width = <2>;
+			};
+		};
 	};
 };
-- 
1.8.1.5

[PATCH v6 5/5] ARM: mvebu: Add Device Bus and CFI flash memory support to defconfig

[Ezequiel Garcia]

This patch selects the devbus driver as part of the mvebu default
config, along with the required options to detect and support
CFI flash memories.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/configs/mvebu_defconfig | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/configs/mvebu_defconfig b/arch/arm/configs/mvebu_defconfig
index 2ec8119..fe8ba26 100644
--- a/arch/arm/configs/mvebu_defconfig
+++ b/arch/arm/configs/mvebu_defconfig
@@ -46,6 +46,11 @@ CONFIG_I2C_MV64XXX=y
 CONFIG_MTD=y
 CONFIG_MTD_CHAR=y
 CONFIG_MTD_M25P80=y
+CONFIG_MTD_CFI=y
+CONFIG_MTD_CFI_INTELEXT=y
+CONFIG_MTD_CFI_AMDSTD=y
+CONFIG_MTD_CFI_STAA=y
+CONFIG_MTD_PHYSMAP_OF=y
 CONFIG_SERIAL_8250_DW=y
 CONFIG_GPIOLIB=y
 CONFIG_GPIO_SYSFS=y
@@ -65,6 +70,8 @@ CONFIG_RTC_DRV_S35390A=y
 CONFIG_RTC_DRV_MV=y
 CONFIG_DMADEVICES=y
 CONFIG_MV_XOR=y
+CONFIG_MEMORY=y
+CONFIG_MVEBU_DEVBUS=y
 # CONFIG_IOMMU_SUPPORT is not set
 CONFIG_EXT2_FS=y
 CONFIG_EXT3_FS=y
-- 
1.8.1.5

[PATCH v6 1/5] drivers: memory: Introduce Marvell EBU Device Bus driver

[Jason Gunthorpe]

On Tue, Apr 09, 2013 at 05:26:17PM -0300, Ezequiel Garcia wrote:
> +	/*
> +	 * Since this is only part of the workaround,
> +	 * we can do this dirty 'ranges' property parsing.
> +	 * Of course, this will be removed once the address windows
> +	 * are declared in the device tree.
> +	 */
> +	err = of_property_read_u32_array(node, "ranges", addr_region,
> +					 ARRAY_SIZE(addr_region));
> +	if (err < 0) {
> +		dev_err(dev, "%s has a malformed 'range' property\n",
> +			node->full_name);
> +		return err;
> +	}

> +	/*
> +	 * Create an mbus address windows.
> +	 * FIXME: Remove this, together with the above code, once the
> +	 * address windows are declared in the device tree.
> +	 */
> +	err = mvebu_mbus_add_window(devbus_wins[cs],
> +				    addr_region[1], addr_region[2]);

Oh, this is a dangerous way to parse ranges.. 

Try something like:

const __be32 *prop;
u64 base;
u64 size;

prop = of_get_property("ranges",&psize);
if (prop == NULL || psize != of_n_addr_cells(node) + of_n_size_cells(node))
   err;
base = of_translate_address(node,prop);
if (base == OF_BAD_ADDR)
   err;
size = of_read_number(prop + of_n_addr_cells(node),of_n_size_cells(node));

err = mvebu_mbus_add_window(devbus_wins[cs],base,size);

I omitted some error checking.

Jason

[PATCH v6 1/5] drivers: memory: Introduce Marvell EBU Device Bus driver

[Ezequiel Garcia]

On Tue, Apr 09, 2013 at 02:38:55PM -0600, Jason Gunthorpe wrote:
> On Tue, Apr 09, 2013 at 05:26:17PM -0300, Ezequiel Garcia wrote:
> > +	/*
> > +	 * Since this is only part of the workaround,
> > +	 * we can do this dirty 'ranges' property parsing.
> > +	 * Of course, this will be removed once the address windows
> > +	 * are declared in the device tree.
> > +	 */
> > +	err = of_property_read_u32_array(node, "ranges", addr_region,
> > +					 ARRAY_SIZE(addr_region));
> > +	if (err < 0) {
> > +		dev_err(dev, "%s has a malformed 'range' property\n",
> > +			node->full_name);
> > +		return err;
> > +	}
> 
> > +	/*
> > +	 * Create an mbus address windows.
> > +	 * FIXME: Remove this, together with the above code, once the
> > +	 * address windows are declared in the device tree.
> > +	 */
> > +	err = mvebu_mbus_add_window(devbus_wins[cs],
> > +				    addr_region[1], addr_region[2]);
> 
> Oh, this is a dangerous way to parse ranges.. 
> 
> Try something like:
> 
> const __be32 *prop;
> u64 base;
> u64 size;
> 
> prop = of_get_property("ranges",&psize);
> if (prop == NULL || psize != of_n_addr_cells(node) + of_n_size_cells(node))
>    err;
> base = of_translate_address(node,prop);
> if (base == OF_BAD_ADDR)
>    err;
> size = of_read_number(prop + of_n_addr_cells(node),of_n_size_cells(node));
> 
> err = mvebu_mbus_add_window(devbus_wins[cs],base,size);
>

No problem, I'll try something like the above.

Mind explaining me why do you think it's dangerous
or in what cases do you expect the other (dirty) solution to break?
-- 
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com

[PATCH v6 1/5] drivers: memory: Introduce Marvell EBU Device Bus driver

[Ezequiel Garcia]

Hi Jason,

On Tue, Apr 09, 2013 at 02:38:55PM -0600, Jason Gunthorpe wrote:
> On Tue, Apr 09, 2013 at 05:26:17PM -0300, Ezequiel Garcia wrote:
> > +	/*
> > +	 * Since this is only part of the workaround,
> > +	 * we can do this dirty 'ranges' property parsing.
> > +	 * Of course, this will be removed once the address windows
> > +	 * are declared in the device tree.
> > +	 */
> > +	err = of_property_read_u32_array(node, "ranges", addr_region,
> > +					 ARRAY_SIZE(addr_region));
> 
> Oh, this is a dangerous way to parse ranges.. 
> 
> Try something like:
> 
> const __be32 *prop;
> u64 base;
> u64 size;
> 
> prop = of_get_property("ranges",&psize);
> if (prop == NULL || psize != of_n_addr_cells(node) + of_n_size_cells(node))
>    err;
> base = of_translate_address(node,prop);
> if (base == OF_BAD_ADDR)
>    err;
> size = of_read_number(prop + of_n_addr_cells(node),of_n_size_cells(node));
> 

Thanks for giving me these hints!

Following your suggestion, here's a working piece of the ranges parsing code,
how does this look?

const __be32 *ranges;
int addr_cells, p_addr_cells, size_cells;
int ranges_len, tuple_len;
u32 base, size;

p_addr_cells = of_n_addr_cells(node->parent);
addr_cells = of_n_addr_cells(node);
size_cells = of_n_size_cells(node);
tuple_len = (p_addr_cells + addr_cells + size_cells) * sizeof(__be32);

ranges = of_get_property(node, "ranges", &ranges_len);
if (ranges == NULL || ranges_len != tuple_len)
	return -EINVAL;

base = of_translate_address(node, ranges + addr_cells);
if (base == 0 || base == OF_BAD_ADDR)
	return -EINVAL;
size = of_read_number(ranges + addr_cells + p_addr_cells, size_cells);

-- 
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com

[PATCH v6 1/5] drivers: memory: Introduce Marvell EBU Device Bus driver

[Jason Gunthorpe]

On Wed, Apr 10, 2013 at 07:19:57AM -0300, Ezequiel Garcia wrote:
> Hi Jason,
> 
> On Tue, Apr 09, 2013 at 02:38:55PM -0600, Jason Gunthorpe wrote:
> > On Tue, Apr 09, 2013 at 05:26:17PM -0300, Ezequiel Garcia wrote:
> > > +	/*
> > > +	 * Since this is only part of the workaround,
> > > +	 * we can do this dirty 'ranges' property parsing.
> > > +	 * Of course, this will be removed once the address windows
> > > +	 * are declared in the device tree.
> > > +	 */
> > > +	err = of_property_read_u32_array(node, "ranges", addr_region,
> > > +					 ARRAY_SIZE(addr_region));
> > 
> > Oh, this is a dangerous way to parse ranges.. 
> > 
> > Try something like:
> > 
> > const __be32 *prop;
> > u64 base;
> > u64 size;
> > 
> > prop = of_get_property("ranges",&psize);
> > if (prop == NULL || psize != of_n_addr_cells(node) + of_n_size_cells(node))
> >    err;
> > base = of_translate_address(node,prop);
> > if (base == OF_BAD_ADDR)
> >    err;
> > size = of_read_number(prop + of_n_addr_cells(node),of_n_size_cells(node));
> > 
> 
> Thanks for giving me these hints!

NP, the motivation for doing this properly is to support cases where
p_addr_cells/addr_cells/size_cells is != 1, and to support cases where
the parent bus address is not the CPU address. The proposed bindings
for mbus will exercise both of these conditions..

> Following your suggestion, here's a working piece of the ranges parsing code,
> how does this look?
> 
> const __be32 *ranges;
> int addr_cells, p_addr_cells, size_cells;
> int ranges_len, tuple_len;
> u32 base, size;
> 
> p_addr_cells = of_n_addr_cells(node->parent);

I wonder if of_get_parent / of_node_put is technically needed here?

> addr_cells = of_n_addr_cells(node);
> size_cells = of_n_size_cells(node);
> tuple_len = (p_addr_cells + addr_cells + size_cells) * sizeof(__be32);
> 
> ranges = of_get_property(node, "ranges", &ranges_len);
> if (ranges == NULL || ranges_len != tuple_len)
> 	return -EINVAL;
> 
> base = of_translate_address(node, ranges + addr_cells);
> if (base == 0 || base == OF_BAD_ADDR)
> 	return -EINVAL;

Why the check for base == 0?

> size = of_read_number(ranges + addr_cells + p_addr_cells, size_cells);

Everything basically looks right. I definitely forgot the include the
p_addr in my quick sample.

Jason

[PATCH v6 1/5] drivers: memory: Introduce Marvell EBU Device Bus driver

[Ezequiel Garcia]

Hi Jason,

On Wed, Apr 10, 2013 at 10:57:50AM -0600, Jason Gunthorpe wrote:
> On Wed, Apr 10, 2013 at 07:19:57AM -0300, Ezequiel Garcia wrote:
> > Hi Jason,
> > 
> > On Tue, Apr 09, 2013 at 02:38:55PM -0600, Jason Gunthorpe wrote:
> > > On Tue, Apr 09, 2013 at 05:26:17PM -0300, Ezequiel Garcia wrote:
> > > > +	/*
> > > > +	 * Since this is only part of the workaround,
> > > > +	 * we can do this dirty 'ranges' property parsing.
> > > > +	 * Of course, this will be removed once the address windows
> > > > +	 * are declared in the device tree.
> > > > +	 */
> > > > +	err = of_property_read_u32_array(node, "ranges", addr_region,
> > > > +					 ARRAY_SIZE(addr_region));
> > > 
> > > Oh, this is a dangerous way to parse ranges.. 
> > > 
> > > Try something like:
> > > 
> > > const __be32 *prop;
> > > u64 base;
> > > u64 size;
> > > 
> > > prop = of_get_property("ranges",&psize);
> > > if (prop == NULL || psize != of_n_addr_cells(node) + of_n_size_cells(node))
> > >    err;
> > > base = of_translate_address(node,prop);
> > > if (base == OF_BAD_ADDR)
> > >    err;
> > > size = of_read_number(prop + of_n_addr_cells(node),of_n_size_cells(node));
> > > 
> > 
> > Thanks for giving me these hints!
> 
> NP, the motivation for doing this properly is to support cases where
> p_addr_cells/addr_cells/size_cells is != 1, and to support cases where
> the parent bus address is not the CPU address. The proposed bindings
> for mbus will exercise both of these conditions..
> 
> > Following your suggestion, here's a working piece of the ranges parsing code,
> > how does this look?
> > 
> > const __be32 *ranges;
> > int addr_cells, p_addr_cells, size_cells;
> > int ranges_len, tuple_len;
> > u32 base, size;
> > 
> > p_addr_cells = of_n_addr_cells(node->parent);
> 
> I wonder if of_get_parent / of_node_put is technically needed here?
>

Yes, that sounds definitely better.

> > addr_cells = of_n_addr_cells(node);
> > size_cells = of_n_size_cells(node);
> > tuple_len = (p_addr_cells + addr_cells + size_cells) * sizeof(__be32);
> > 
> > ranges = of_get_property(node, "ranges", &ranges_len);
> > if (ranges == NULL || ranges_len != tuple_len)
> > 	return -EINVAL;
> > 
> > base = of_translate_address(node, ranges + addr_cells);
> > if (base == 0 || base == OF_BAD_ADDR)
> > 	return -EINVAL;
> 
> Why the check for base == 0?
> 

Well, when writing this code my first experiments where failing
(because the code was wrong) and I was getting base=0.
So I added this to catch that error.

Thinking it twice, it doesn't seem correct to check that.

> > size = of_read_number(ranges + addr_cells + p_addr_cells, size_cells);
> 
> Everything basically looks right. I definitely forgot the include the
> p_addr in my quick sample.
> 

Great, I'll send the v7, with these two fixes.

-- 
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com