reset: Add generic reset driver

This patch adds a generic reset driver. It is designed to be useful when
one has a register in a regmap which contains bits that reset other
devices. I thought this seemed like a very generic use, so here is a
generic driver. The overall structure has been modeled on the syscon-reboot
driver.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 60 insertions, 0 deletions

diff --git a/test/dm/Makefile b/test/dm/Makefile
index 518ee8e..0d1c66f 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -75,4 +75,5 @@ obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o
 obj-$(CONFIG_DM_RNG) += rng.o
 obj-$(CONFIG_CLK_K210_SET_RATE) += k210_pll.o
 obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o
+obj-$(CONFIG_RESET_SYSCON) += syscon-reset.o
 endif
diff --git a/test/dm/syscon-reset.c b/test/dm/syscon-reset.c
new file mode 100644
index 0000000..edabdb2
--- /dev/null
+++ b/test/dm/syscon-reset.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/test.h>
+#include <regmap.h>
+#include <reset.h>
+#include <syscon.h>
+#include <test/ut.h>
+#include <asm/test.h>
+#include <linux/bitops.h>
+
+/* The following values must match the device tree */
+#define TEST_RESET_REG 1
+#define TEST_RESET_ASSERT_HIGH 0
+#define TEST_RESET_ASSERT (TEST_RESET_ASSERT_HIGH ? (u32)-1 : (u32)0)
+#define TEST_RESET_DEASSERT (~TEST_RESET_ASSERT)
+
+#define TEST_RESET_VALID 15
+#define TEST_RESET_NOMASK 30
+#define TEST_RESET_OUTOFRANGE 60
+
+static int dm_test_syscon_reset(struct unit_test_state *uts)
+{
+	struct regmap *map;
+	struct reset_ctl rst;
+	struct udevice *reset;
+	struct udevice *syscon;
+	struct udevice *syscon_reset;
+	uint reg;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_MISC, "syscon-reset-test",
+					      &reset));
+	ut_assertok(uclass_get_device_by_name(UCLASS_SYSCON, "syscon@0",
+					      &syscon));
+	ut_assertok(uclass_get_device_by_name(UCLASS_RESET, "syscon-reset",
+					      &syscon_reset));
+	ut_assertok_ptr((map = syscon_get_regmap(syscon)));
+
+	ut_asserteq(-EINVAL, reset_get_by_name(reset, "no_mask", &rst));
+	ut_asserteq(-EINVAL, reset_get_by_name(reset, "out_of_range", &rst));
+	ut_assertok(reset_get_by_name(reset, "valid", &rst));
+
+	sandbox_set_enable_memio(true);
+	ut_assertok(regmap_write(map, TEST_RESET_REG, TEST_RESET_DEASSERT));
+	ut_assertok(reset_assert(&rst));
+	ut_assertok(regmap_read(map, TEST_RESET_REG, &reg));
+	ut_asserteq(TEST_RESET_DEASSERT ^ BIT(TEST_RESET_VALID), reg);
+
+	ut_assertok(reset_deassert(&rst));
+	ut_assertok(regmap_read(map, TEST_RESET_REG, &reg));
+	ut_asserteq(TEST_RESET_DEASSERT, reg);
+
+	return 0;
+}
+DM_TEST(dm_test_syscon_reset, DM_TESTF_SCAN_FDT);