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authorNeil Armstrong <narmstrong@baylibre.com>2018-03-29 14:55:25 +0200
committerTom Rini <trini@konsulko.com>2018-04-10 11:52:16 -0400
commit20367bb560f0bc3243ccac234ca7ae2ba8f94a5f (patch)
treeecd422b353ff5fff8473f49686121eafb8d7c036
parent060690663d758375c31de524aa9328e0ac350a50 (diff)
reset: Add Amlogic Meson Reset Controller
The Amlogic Meson SoCs embeds up to 256 reset lines, add the corresponding driver. Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
-rw-r--r--drivers/reset/Kconfig8
-rw-r--r--drivers/reset/Makefile1
-rw-r--r--drivers/reset/reset-meson.c90
3 files changed, 99 insertions, 0 deletions
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 71a786bab5..ccfdac7823 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -83,4 +83,12 @@ config RESET_ROCKCHIP
though is that some reset signals, like I2C or MISC reset multiple
devices.
+config RESET_MESON
+ bool "Reset controller driver for Amlogic Meson SoCs"
+ depends on DM_RESET && ARCH_MESON
+ imply REGMAP
+ default y
+ help
+ Support for reset controller on Amlogic Meson SoC.
+
endmenu
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 7d7e080c78..d1d5146825 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o
obj-$(CONFIG_RESET_ROCKCHIP) += reset-rockchip.o
+obj-$(CONFIG_RESET_MESON) += reset-meson.o
diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c
new file mode 100644
index 0000000000..5324f86f5f
--- /dev/null
+++ b/drivers/reset/reset-meson.c
@@ -0,0 +1,90 @@
+/*
+ * Amlogic Meson Reset Controller driver
+ *
+ * Copyright (c) 2018 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <reset-uclass.h>
+#include <regmap.h>
+
+#define REG_COUNT 8
+#define BITS_PER_REG 32
+#define LEVEL_OFFSET 0x7c
+
+struct meson_reset_priv {
+ struct regmap *regmap;
+};
+
+static int meson_reset_request(struct reset_ctl *reset_ctl)
+{
+ if (reset_ctl->id > (REG_COUNT * BITS_PER_REG))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int meson_reset_free(struct reset_ctl *reset_ctl)
+{
+ return 0;
+}
+
+static int meson_reset_level(struct reset_ctl *reset_ctl, bool assert)
+{
+ struct meson_reset_priv *priv = dev_get_priv(reset_ctl->dev);
+ uint bank = reset_ctl->id / BITS_PER_REG;
+ uint offset = reset_ctl->id % BITS_PER_REG;
+ uint reg_offset = LEVEL_OFFSET + (bank << 2);
+ uint val;
+
+ regmap_read(priv->regmap, reg_offset, &val);
+ if (assert)
+ val &= ~BIT(offset);
+ else
+ val |= BIT(offset);
+ regmap_write(priv->regmap, reg_offset, val);
+
+ return 0;
+}
+
+static int meson_reset_assert(struct reset_ctl *reset_ctl)
+{
+ return meson_reset_level(reset_ctl, true);
+}
+
+static int meson_reset_deassert(struct reset_ctl *reset_ctl)
+{
+ return meson_reset_level(reset_ctl, false);
+}
+
+struct reset_ops meson_reset_ops = {
+ .request = meson_reset_request,
+ .free = meson_reset_free,
+ .rst_assert = meson_reset_assert,
+ .rst_deassert = meson_reset_deassert,
+};
+
+static const struct udevice_id meson_reset_ids[] = {
+ { .compatible = "amlogic,meson-gxbb-reset" },
+ { }
+};
+
+static int meson_reset_probe(struct udevice *dev)
+{
+ struct meson_reset_priv *priv = dev_get_priv(dev);
+
+ return regmap_init_mem(dev, &priv->regmap);
+}
+
+U_BOOT_DRIVER(meson_reset) = {
+ .name = "meson_reset",
+ .id = UCLASS_RESET,
+ .of_match = meson_reset_ids,
+ .probe = meson_reset_probe,
+ .ops = &meson_reset_ops,
+ .priv_auto_alloc_size = sizeof(struct meson_reset_priv),
+};