Signed-off-by: Joachim Eastwood <manab...@gmail.com>
---
 drivers/memory/Kconfig  |   8 ++
 drivers/memory/Makefile |   1 +
 drivers/memory/pl172.c  | 302 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 311 insertions(+)
 create mode 100644 drivers/memory/pl172.c

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 868036f70f8f..f69a8842ec69 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -7,6 +7,14 @@ menuconfig MEMORY
 
 if MEMORY
 
+config ARM_PL172_MPMC
+       tristate "ARM PL172 MPMC driver"
+       depends on ARM_AMBA && OF
+       help
+         This selects the ARM PrimeCell PL172 MultiPort Memory Controller.
+         If you have an embedded system with an AMBA bus and a PL172
+         controller, say Y or M here.
+
 config ATMEL_SDRAMC
        bool "Atmel (Multi-port DDR-)SDRAM Controller"
        default y
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index b670441e3cdf..1c46af501610 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -5,6 +5,7 @@
 ifeq ($(CONFIG_DDR),y)
 obj-$(CONFIG_OF)               += of_memory.o
 endif
+obj-$(CONFIG_ARM_PL172_MPMC)   += pl172.o
 obj-$(CONFIG_ATMEL_SDRAMC)     += atmel-sdramc.o
 obj-$(CONFIG_TI_AEMIF)         += ti-aemif.o
 obj-$(CONFIG_TI_EMIF)          += emif.o
diff --git a/drivers/memory/pl172.c b/drivers/memory/pl172.c
new file mode 100644
index 000000000000..552f92da9369
--- /dev/null
+++ b/drivers/memory/pl172.c
@@ -0,0 +1,302 @@
+/*
+ * Memory controller driver for ARM PrimeCell PL172
+ * PrimeCell MultiPort Memory Controller (PL172)
+ *
+ * Copyright (C) 2015 Joachim Eastwood <manab...@gmail.com>
+ *
+ * Based on:
+ * TI AEMIF driver, Copyright (C) 2010 - 2013 Texas Instruments Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/time.h>
+
+#define MPMC_STATIC_CFG(n)             (0x200 + 0x20 * n)
+#define  MPMC_STATIC_CFG_MW_8BIT       0x0
+#define  MPMC_STATIC_CFG_MW_16BIT      0x1
+#define  MPMC_STATIC_CFG_MW_32BIT      0x2
+#define  MPMC_STATIC_CFG_PM            BIT(3)
+#define  MPMC_STATIC_CFG_PC            BIT(6)
+#define  MPMC_STATIC_CFG_PB            BIT(7)
+#define  MPMC_STATIC_CFG_EW            BIT(8)
+#define  MPMC_STATIC_CFG_B             BIT(19)
+#define  MPMC_STATIC_CFG_P             BIT(20)
+#define MPMC_STATIC_WAIT_WEN(n)                (0x204 + 0x20 * n)
+#define  MPMC_STATIC_WAIT_WEN_MAX      0x0f
+#define MPMC_STATIC_WAIT_OEN(n)                (0x208 + 0x20 * n)
+#define  MPMC_STATIC_WAIT_OEN_MAX      0x0f
+#define MPMC_STATIC_WAIT_RD(n)         (0x20c + 0x20 * n)
+#define  MPMC_STATIC_WAIT_RD_MAX       0x1f
+#define MPMC_STATIC_WAIT_PAGE(n)       (0x210 + 0x20 * n)
+#define  MPMC_STATIC_WAIT_PAGE_MAX     0x1f
+#define MPMC_STATIC_WAIT_WR(n)         (0x214 + 0x20 * n)
+#define  MPMC_STATIC_WAIT_WR_MAX       0x1f
+#define MPMC_STATIC_WAIT_TURN(n)       (0x218 + 0x20 * n)
+#define  MPMC_STATIC_WAIT_TURN_MAX     0x0f
+
+/* Maximum number of static chip selects */
+#define PL172_MAX_CS           4
+
+struct pl172_data {
+       void __iomem *base;
+       unsigned long rate;
+       struct clk *clk;
+};
+
+static int pl172_timing_prop(struct amba_device *adev,
+                            const struct device_node *np, const char *name,
+                            u32 reg_offset, u32 max, int start)
+{
+       struct pl172_data *pl172 = amba_get_drvdata(adev);
+       int cycles;
+       u32 val;
+
+       if (!of_property_read_u32(np, name, &val)) {
+               cycles = DIV_ROUND_UP(val * pl172->rate, NSEC_PER_MSEC) - start;
+               if (cycles < 0) {
+                       cycles = 0;
+               } else if (cycles > max) {
+                       dev_err(&adev->dev, "%s timing too tight\n", name);
+                       return -EINVAL;
+               }
+
+               writel(cycles, pl172->base + reg_offset);
+       }
+
+       dev_dbg(&adev->dev, "%s: %u cycle(s)\n", name, start +
+                               readl(pl172->base + reg_offset));
+
+       return 0;
+}
+
+static int pl172_setup_static(struct amba_device *adev,
+                             struct device_node *np, u32 cs)
+{
+       struct pl172_data *pl172 = amba_get_drvdata(adev);
+       u32 cfg;
+       int ret;
+
+       /* MPMC static memory configuration */
+       if (!of_property_read_u32(np, "mpmc,memory-width", &cfg)) {
+               if (cfg == 8) {
+                       cfg = MPMC_STATIC_CFG_MW_8BIT;
+               } else if (cfg == 16) {
+                       cfg = MPMC_STATIC_CFG_MW_16BIT;
+               } else if (cfg == 32) {
+                       cfg = MPMC_STATIC_CFG_MW_32BIT;
+               } else {
+                       dev_err(&adev->dev, "invalid memory width cs%u\n", cs);
+                       return -EINVAL;
+               }
+       } else {
+               dev_err(&adev->dev, "memory-width property required\n");
+               return -EINVAL;
+       }
+
+       if (of_property_read_bool(np, "mpmc,async-page-mode"))
+               cfg |= MPMC_STATIC_CFG_PM;
+
+       if (of_property_read_bool(np, "mpmc,cs-active-high"))
+               cfg |= MPMC_STATIC_CFG_PC;
+
+       if (of_property_read_bool(np, "mpmc,byte-lane-low"))
+               cfg |= MPMC_STATIC_CFG_PB;
+
+       if (of_property_read_bool(np, "mpmc,extended-wait"))
+               cfg |= MPMC_STATIC_CFG_EW;
+
+       if (of_property_read_bool(np, "mpmc,buffer-enable"))
+               cfg |= MPMC_STATIC_CFG_B;
+
+       if (of_property_read_bool(np, "mpmc,write-protect"))
+               cfg |= MPMC_STATIC_CFG_P;
+
+       writel(cfg, pl172->base + MPMC_STATIC_CFG(cs));
+       dev_dbg(&adev->dev, "mpmc static config cs%u: 0x%08x\n", cs, cfg);
+
+       /* MPMC static memory timing */
+       ret = pl172_timing_prop(adev, np, "mpmc,write-enable-delay",
+                               MPMC_STATIC_WAIT_WEN(cs),
+                               MPMC_STATIC_WAIT_WEN_MAX, 1);
+       if (ret)
+               goto fail;
+
+       ret = pl172_timing_prop(adev, np, "mpmc,output-enable-delay",
+                               MPMC_STATIC_WAIT_OEN(cs),
+                               MPMC_STATIC_WAIT_OEN_MAX, 0);
+       if (ret)
+               goto fail;
+
+       ret = pl172_timing_prop(adev, np, "mpmc,read-access-delay",
+                               MPMC_STATIC_WAIT_RD(cs),
+                               MPMC_STATIC_WAIT_RD_MAX, 1);
+       if (ret)
+               goto fail;
+
+       ret = pl172_timing_prop(adev, np, "mpmc,page-mode-read-delay",
+                               MPMC_STATIC_WAIT_PAGE(cs),
+                               MPMC_STATIC_WAIT_PAGE_MAX, 1);
+       if (ret)
+               goto fail;
+
+       ret = pl172_timing_prop(adev, np, "mpmc,write-access-delay",
+                               MPMC_STATIC_WAIT_WR(cs),
+                               MPMC_STATIC_WAIT_WR_MAX, 2);
+       if (ret)
+               goto fail;
+
+       ret = pl172_timing_prop(adev, np, "mpmc,turn-round-delay",
+                               MPMC_STATIC_WAIT_TURN(cs),
+                               MPMC_STATIC_WAIT_TURN_MAX, 1);
+       if (ret)
+               goto fail;
+
+       return 0;
+fail:
+       dev_err(&adev->dev, "failed to configure cs%u\n", cs);
+       return ret;
+}
+
+static int pl172_parse_cs_config(struct amba_device *adev,
+                                struct device_node *np)
+{
+       u32 cs;
+
+       if (!of_property_read_u32(np, "mpmc,cs", &cs)) {
+               if (cs >= PL172_MAX_CS) {
+                       dev_err(&adev->dev, "cs%u invalid\n", cs);
+                       return -EINVAL;
+               }
+
+               return pl172_setup_static(adev, np, cs);
+       }
+
+       dev_err(&adev->dev, "cs property required\n");
+
+       return -EINVAL;
+}
+
+static const char * const pl172_revisions[] = {"r1", "r2", "r2p3", "r2p4"};
+
+static int pl172_probe(struct amba_device *adev, const struct amba_id *id)
+{
+       struct device_node *child_np, *np = adev->dev.of_node;
+       struct device *dev = &adev->dev;
+       static const char *rev = "?";
+       struct pl172_data *pl172;
+       int ret;
+
+       if (amba_part(adev) == 0x172) {
+               if (amba_rev(adev) < ARRAY_SIZE(pl172_revisions))
+                       rev = pl172_revisions[amba_rev(adev)];
+       }
+
+       dev_info(dev, "ARM PL%x revision %s\n", amba_part(adev), rev);
+
+       pl172 = devm_kzalloc(dev, sizeof(*pl172), GFP_KERNEL);
+       if (!pl172)
+               return -ENOMEM;
+
+       pl172->clk = devm_clk_get(dev, "mpmcclk");
+       if (IS_ERR(pl172->clk)) {
+               dev_err(dev, "no mpmcclk provided clock\n");
+               return PTR_ERR(pl172->clk);
+       }
+
+       ret = clk_prepare_enable(pl172->clk);
+       if (ret) {
+               dev_err(dev, "unable to mpmcclk enable clock\n");
+               return ret;
+       }
+
+       pl172->rate = clk_get_rate(pl172->clk) / MSEC_PER_SEC;
+       if (!pl172->rate) {
+               dev_err(dev, "unable to get mpmcclk clock rate\n");
+               ret = -EINVAL;
+               goto err_clk_enable;
+       }
+
+       ret = amba_request_regions(adev, NULL);
+       if (ret) {
+               dev_err(dev, "unable to request AMBA regions\n");
+               goto err_clk_enable;
+       }
+
+       pl172->base = devm_ioremap(dev, adev->res.start,
+                                  resource_size(&adev->res));
+       if (!pl172->base) {
+               dev_err(dev, "ioremap failed\n");
+               ret = -ENOMEM;
+               goto err_no_ioremap;
+       }
+
+       amba_set_drvdata(adev, pl172);
+
+       /*
+        * Loop through each child node, which represent a chip select, and
+        * configure parameters and timing. If successful; populate devices
+        * under that node.
+        */
+       for_each_available_child_of_node(np, child_np) {
+               ret = pl172_parse_cs_config(adev, child_np);
+               if (ret)
+                       continue;
+
+               of_platform_populate(child_np, of_default_bus_match_table,
+                                    NULL, dev);
+       }
+
+       return 0;
+
+err_no_ioremap:
+       amba_release_regions(adev);
+err_clk_enable:
+       clk_disable_unprepare(pl172->clk);
+       return ret;
+}
+
+static int pl172_remove(struct amba_device *adev)
+{
+       struct pl172_data *pl172 = amba_get_drvdata(adev);
+
+       clk_disable_unprepare(pl172->clk);
+       amba_release_regions(adev);
+
+       return 0;
+}
+
+static struct amba_id pl172_ids[] = {
+       {
+               .id     = 0x07341172,
+               .mask   = 0xffffffff,
+       },
+       { 0, 0 },
+};
+MODULE_DEVICE_TABLE(amba, pl172_ids);
+
+static struct amba_driver pl172_driver = {
+       .drv = {
+               .name   = "memory-pl172",
+       },
+       .probe          = pl172_probe,
+       .remove         = pl172_remove,
+       .id_table       = pl172_ids,
+};
+module_amba_driver(pl172_driver);
+
+MODULE_AUTHOR("Joachim Eastwood <manab...@gmail.com>");
+MODULE_DESCRIPTION("PL172 Memory Controller Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.8.0

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