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path: root/drivers/memory/mvebu-devbus.c
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Diffstat (limited to 'drivers/memory/mvebu-devbus.c')
-rw-r--r--drivers/memory/mvebu-devbus.c362
1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/memory/mvebu-devbus.c b/drivers/memory/mvebu-devbus.c
new file mode 100644
index 00000000000..ff7138fd66d
--- /dev/null
+++ b/drivers/memory/mvebu-devbus.c
@@ -0,0 +1,362 @@
+/*
+ * 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",
+ .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");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 08:15:22 +0000