Initial import

1 files changed, 361 insertions, 0 deletions

diff --git a/drivers/memory/mvebu-devbus.c b/drivers/memory/mvebu-devbus.c
new file mode 100644
index 000000000..24852812f
--- /dev/null
+++ b/drivers/memory/mvebu-devbus.c
@@ -0,0 +1,361 @@
+/*
+ * Marvell EBU SoC Device Bus Controller
+ * (memory controller for NOR/NAND/SRAM/FPGA devices)
+ *
+ * Copyright (C) 2013-2014 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 ARMADA_DEV_WIDTH_SHIFT		30
+#define ARMADA_BADR_SKEW_SHIFT		28
+#define ARMADA_RD_HOLD_SHIFT		23
+#define ARMADA_ACC_NEXT_SHIFT		17
+#define ARMADA_RD_SETUP_SHIFT		12
+#define ARMADA_ACC_FIRST_SHIFT		6
+
+#define ARMADA_SYNC_ENABLE_SHIFT	24
+#define ARMADA_WR_HIGH_SHIFT		16
+#define ARMADA_WR_LOW_SHIFT		8
+
+#define ARMADA_READ_PARAM_OFFSET	0x0
+#define ARMADA_WRITE_PARAM_OFFSET	0x4
+
+#define ORION_RESERVED			(0x2 << 30)
+#define ORION_BADR_SKEW_SHIFT		28
+#define ORION_WR_HIGH_EXT_BIT		BIT(27)
+#define ORION_WR_HIGH_EXT_MASK		0x8
+#define ORION_WR_LOW_EXT_BIT		BIT(26)
+#define ORION_WR_LOW_EXT_MASK		0x8
+#define ORION_ALE_WR_EXT_BIT		BIT(25)
+#define ORION_ALE_WR_EXT_MASK		0x8
+#define ORION_ACC_NEXT_EXT_BIT		BIT(24)
+#define ORION_ACC_NEXT_EXT_MASK		0x10
+#define ORION_ACC_FIRST_EXT_BIT		BIT(23)
+#define ORION_ACC_FIRST_EXT_MASK	0x10
+#define ORION_TURN_OFF_EXT_BIT		BIT(22)
+#define ORION_TURN_OFF_EXT_MASK		0x8
+#define ORION_DEV_WIDTH_SHIFT		20
+#define ORION_WR_HIGH_SHIFT		17
+#define ORION_WR_HIGH_MASK		0x7
+#define ORION_WR_LOW_SHIFT		14
+#define ORION_WR_LOW_MASK		0x7
+#define ORION_ALE_WR_SHIFT		11
+#define ORION_ALE_WR_MASK		0x7
+#define ORION_ACC_NEXT_SHIFT		7
+#define ORION_ACC_NEXT_MASK		0xF
+#define ORION_ACC_FIRST_SHIFT		3
+#define ORION_ACC_FIRST_MASK		0xF
+#define ORION_TURN_OFF_SHIFT		0
+#define ORION_TURN_OFF_MASK		0x7
+
+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_get_timing_params(struct devbus *devbus,
+				    struct device_node *node,
+				    struct devbus_read_params *r,
+				    struct devbus_write_params *w)
+{
+	int err;
+
+	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;
+	}
+
+	/*
+	 * The bus width is encoded into the register as 0 for 8 bits,
+	 * and 1 for 16 bits, so we do the necessary conversion here.
+	 */
+	if (r->bus_width == 8)
+		r->bus_width = 0;
+	else if (r->bus_width == 16)
+		r->bus_width = 1;
+	else {
+		dev_err(devbus->dev, "invalid bus width %d\n", r->bus_width);
+		return -EINVAL;
+	}
+
+	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;
+
+	if (of_device_is_compatible(devbus->dev->of_node, "marvell,mvebu-devbus")) {
+		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;
+
+		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;
+
+	return 0;
+}
+
+static void devbus_orion_set_timing_params(struct devbus *devbus,
+					  struct device_node *node,
+					  struct devbus_read_params *r,
+					  struct devbus_write_params *w)
+{
+	u32 value;
+
+	/*
+	 * The hardware designers found it would be a good idea to
+	 * split most of the values in the register into two fields:
+	 * one containing all the low-order bits, and another one
+	 * containing just the high-order bit. For all of those
+	 * fields, we have to split the value into these two parts.
+	 */
+	value =	(r->turn_off   & ORION_TURN_OFF_MASK)  << ORION_TURN_OFF_SHIFT  |
+		(r->acc_first  & ORION_ACC_FIRST_MASK) << ORION_ACC_FIRST_SHIFT |
+		(r->acc_next   & ORION_ACC_NEXT_MASK)  << ORION_ACC_NEXT_SHIFT  |
+		(w->ale_wr     & ORION_ALE_WR_MASK)    << ORION_ALE_WR_SHIFT    |
+		(w->wr_low     & ORION_WR_LOW_MASK)    << ORION_WR_LOW_SHIFT    |
+		(w->wr_high    & ORION_WR_HIGH_MASK)   << ORION_WR_HIGH_SHIFT   |
+		r->bus_width                           << ORION_DEV_WIDTH_SHIFT |
+		((r->turn_off  & ORION_TURN_OFF_EXT_MASK)  ? ORION_TURN_OFF_EXT_BIT  : 0) |
+		((r->acc_first & ORION_ACC_FIRST_EXT_MASK) ? ORION_ACC_FIRST_EXT_BIT : 0) |
+		((r->acc_next  & ORION_ACC_NEXT_EXT_MASK)  ? ORION_ACC_NEXT_EXT_BIT  : 0) |
+		((w->ale_wr    & ORION_ALE_WR_EXT_MASK)    ? ORION_ALE_WR_EXT_BIT    : 0) |
+		((w->wr_low    & ORION_WR_LOW_EXT_MASK)    ? ORION_WR_LOW_EXT_BIT    : 0) |
+		((w->wr_high   & ORION_WR_HIGH_EXT_MASK)   ? ORION_WR_HIGH_EXT_BIT   : 0) |
+		(r->badr_skew << ORION_BADR_SKEW_SHIFT) |
+		ORION_RESERVED;
+
+	writel(value, devbus->base);
+}
+
+static void devbus_armada_set_timing_params(struct devbus *devbus,
+					   struct device_node *node,
+					   struct devbus_read_params *r,
+					   struct devbus_write_params *w)
+{
+	u32 value;
+
+	/* Set read timings */
+	value = r->bus_width << ARMADA_DEV_WIDTH_SHIFT |
+		r->badr_skew << ARMADA_BADR_SKEW_SHIFT |
+		r->rd_hold   << ARMADA_RD_HOLD_SHIFT   |
+		r->acc_next  << ARMADA_ACC_NEXT_SHIFT  |
+		r->rd_setup  << ARMADA_RD_SETUP_SHIFT  |
+		r->acc_first << ARMADA_ACC_FIRST_SHIFT |
+		r->turn_off;
+
+	dev_dbg(devbus->dev, "read parameters register 0x%p = 0x%x\n",
+		devbus->base + ARMADA_READ_PARAM_OFFSET,
+		value);
+
+	writel(value, devbus->base + ARMADA_READ_PARAM_OFFSET);
+
+	/* Set write timings */
+	value = w->sync_enable  << ARMADA_SYNC_ENABLE_SHIFT |
+		w->wr_low       << ARMADA_WR_LOW_SHIFT      |
+		w->wr_high      << ARMADA_WR_HIGH_SHIFT     |
+		w->ale_wr;
+
+	dev_dbg(devbus->dev, "write parameters register: 0x%p = 0x%x\n",
+		devbus->base + ARMADA_WRITE_PARAM_OFFSET,
+		value);
+
+	writel(value, devbus->base + ARMADA_WRITE_PARAM_OFFSET);
+}
+
+static int mvebu_devbus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = pdev->dev.of_node;
+	struct devbus_read_params r;
+	struct devbus_write_params w;
+	struct devbus *devbus;
+	struct resource *res;
+	struct clk *clk;
+	unsigned long rate;
+	int err;
+
+	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;
+
+	dev_dbg(devbus->dev, "Setting timing parameter, tick is %lu ps\n",
+		devbus->tick_ps);
+
+	if (!of_property_read_bool(node, "devbus,keep-config")) {
+		/* Read the Device Tree node */
+		err = devbus_get_timing_params(devbus, node, &r, &w);
+		if (err < 0)
+			return err;
+
+		/* Set the new timing parameters */
+		if (of_device_is_compatible(node, "marvell,orion-devbus"))
+			devbus_orion_set_timing_params(devbus, node, &r, &w);
+		else
+			devbus_armada_set_timing_params(devbus, node, &r, &w);
+	}
+
+	/*
+	 * 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)
+		return err;
+
+	return 0;
+}
+
+static const struct of_device_id mvebu_devbus_of_match[] = {
+	{ .compatible = "marvell,mvebu-devbus" },
+	{ .compatible = "marvell,orion-devbus" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mvebu_devbus_of_match);
+
+static struct platform_driver mvebu_devbus_driver = {
+	.probe		= mvebu_devbus_probe,
+	.driver		= {
+		.name	= "mvebu-devbus",
+		.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");