[U-Boot] [RFC PATCHv1 1/3] misc: pl310: add a misc driver for the pl310 cache controller

[Dinh Nguyen <dinguyen@kernel.org>]

The driver will read the cache properties from the device tree file and
set it up.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
---
 arch/arm/include/asm/pl310.h |  3 ++
 drivers/misc/Kconfig         |  7 +++
 drivers/misc/Makefile        |  1 +
 drivers/misc/cache-l2x0.c    | 84 ++++++++++++++++++++++++++++++++++++
 4 files changed, 95 insertions(+)
 create mode 100644 drivers/misc/cache-l2x0.c

diff --git a/arch/arm/include/asm/pl310.h b/arch/arm/include/asm/pl310.h
index b83978b1cc..f69e9e45f8 100644
--- a/arch/arm/include/asm/pl310.h
+++ b/arch/arm/include/asm/pl310.h
@@ -18,6 +18,9 @@
 #define L310_SHARED_ATT_OVERRIDE_ENABLE		(1 << 22)
 #define L310_AUX_CTRL_DATA_PREFETCH_MASK	(1 << 28)
 #define L310_AUX_CTRL_INST_PREFETCH_MASK	(1 << 29)
+#define L310_LATENCY_CTRL_SETUP(n)		((n) << 0)
+#define L310_LATENCY_CTRL_RD(n)			((n) << 4)
+#define L310_LATENCY_CTRL_WR(n)			((n) << 8)
 
 #define L2X0_CACHE_ID_PART_MASK     (0xf << 6)
 #define L2X0_CACHE_ID_PART_L310     (3 << 6)
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index d6e677fba8..c5c34b4dbb 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -13,6 +13,13 @@ config MISC
 	  set of generic read, write and ioctl methods may be used to
 	  access the device.
 
+config L2X0_CACHE
+	bool "L2x0 Cache support"
+	depends on MISC
+	help
+	  Select this to enable a PL310 L2 Cache driver. The driver will
+	  configure the L2 Cache settings found in the device tree.
+
 config ALTERA_SYSID
 	bool "Altera Sysid support"
 	depends on MISC
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 6bdf5054f4..ea726f4668 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_SANDBOX) += spltest_sandbox.o
 endif
 endif
 obj-$(CONFIG_ALI152X) += ali512x.o
+obj-$(CONFIG_L2X0_CACHE) += cache-l2x0.o
 obj-$(CONFIG_ALTERA_SYSID) += altera_sysid.o
 obj-$(CONFIG_ATSHA204A) += atsha204a-i2c.o
 obj-$(CONFIG_CBMEM_CONSOLE) += cbmem_console.o
diff --git a/drivers/misc/cache-l2x0.c b/drivers/misc/cache-l2x0.c
new file mode 100644
index 0000000000..b31598b1cd
--- /dev/null
+++ b/drivers/misc/cache-l2x0.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 ARM Limited
+ *
+ * copied from Linux(arch/arm/mm/cache-l2x0.c
+ */
+#include <common.h>
+#include <command.h>
+#include <dm.h>
+
+#include <asm/io.h>
+#include <asm/pl310.h>
+
+static void l2c310_of_parse(struct udevice *dev)
+{
+	u32 tag[3] = { 0, 0, 0 };
+	u32 saved_reg, prefetch_i, prefetch_d;
+	bool shared_override;
+	struct pl310_regs *regs = (struct pl310_regs *)devfdt_get_addr(dev);
+
+	/*Disable the L2 Cache */
+	clrbits_le32(&regs->pl310_ctrl, L2X0_CTRL_EN);
+
+	dev_read_u32(dev, "prefetch-data", &prefetch_d);
+	dev_read_u32(dev, "prefetch-instr", &prefetch_i);
+	shared_override = dev_read_bool(dev, "arm,shared-override");
+
+	saved_reg = readl(&regs->pl310_aux_ctrl);
+	if (prefetch_d)
+		saved_reg |= L310_AUX_CTRL_DATA_PREFETCH_MASK;
+	if (prefetch_i)
+		saved_reg |= L310_AUX_CTRL_INST_PREFETCH_MASK;
+	if (shared_override)
+		saved_reg |= L310_SHARED_ATT_OVERRIDE_ENABLE;
+
+	writel(saved_reg, &regs->pl310_aux_ctrl);
+
+	saved_reg = readl(&regs->pl310_tag_latency_ctrl);
+	dev_read_u32_array(dev, "arm,tag-latency", tag, 3);
+
+	saved_reg |= L310_LATENCY_CTRL_RD(tag[0] - 1) |
+		     L310_LATENCY_CTRL_WR(tag[1] - 1) |
+		     L310_LATENCY_CTRL_SETUP(tag[2] - 1);
+
+	writel(saved_reg, &regs->pl310_tag_latency_ctrl);
+
+	saved_reg = readl(&regs->pl310_data_latency_ctrl);
+	dev_read_u32_array(dev, "arm,data-latency", tag, 3);
+
+	saved_reg |= L310_LATENCY_CTRL_RD(tag[0] - 1) |
+		     L310_LATENCY_CTRL_WR(tag[1] - 1) |
+		     L310_LATENCY_CTRL_SETUP(tag[2] - 1);
+
+	writel(saved_reg, &regs->pl310_data_latency_ctrl);
+
+	/* Enable the L2 cache */
+	setbits_le32(&regs->pl310_ctrl, L2X0_CTRL_EN);
+}
+
+static int l2x0_ofdata_to_platdata(struct udevice *dev)
+{
+	return 0;
+}
+
+static int l2x0_probe(struct udevice *dev)
+{
+	l2c310_of_parse(dev);
+	return 0;
+}
+
+
+static const struct udevice_id l2x0_ids[] = {
+	{ .compatible = "arm,pl310-cache" },
+	{}
+};
+
+U_BOOT_DRIVER(pl310_cache) = {
+	.name   = "pl310_cache",
+	.id     = UCLASS_MISC,
+	.of_match = l2x0_ids,
+	.probe	= l2x0_probe,
+	.ofdata_to_platdata = l2x0_ofdata_to_platdata,
+	.flags  = DM_FLAG_PRE_RELOC,
+};
-- 
2.20.0