Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 181 insertions, 0 deletions

diff --git a/drivers/clk/ux500/reset-prcc.c b/drivers/clk/ux500/reset-prcc.c
new file mode 100644
index 0000000000..f7e48941fb
--- /dev/null
+++ b/drivers/clk/ux500/reset-prcc.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Reset controller portions for the U8500 PRCC
+ * Copyright (C) 2021 Linus Walleij <linus.walleij@linaro.org>
+ */
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/reset-controller.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+
+#include "prcc.h"
+#include "reset-prcc.h"
+
+#define to_u8500_prcc_reset(p) container_of((p), struct u8500_prcc_reset, rcdev)
+
+/* This macro flattens the 2-dimensional PRCC numberspace */
+#define PRCC_RESET_LINE(prcc_num, bit) \
+	(((prcc_num) * PRCC_PERIPHS_PER_CLUSTER) + (bit))
+
+/*
+ * Reset registers in each PRCC - the reset lines are active low
+ * so what you need to do is write a bit for the peripheral you
+ * want to put into reset into the CLEAR register, this will assert
+ * the reset by pulling the line low. SET take the device out of
+ * reset. The status reflects the actual state of the line.
+ */
+#define PRCC_K_SOFTRST_SET		0x018
+#define PRCC_K_SOFTRST_CLEAR		0x01c
+#define PRCC_K_RST_STATUS		0x020
+
+static int prcc_num_to_index(unsigned int num)
+{
+	switch (num) {
+	case 1:
+		return CLKRST1_INDEX;
+	case 2:
+		return CLKRST2_INDEX;
+	case 3:
+		return CLKRST3_INDEX;
+	case 5:
+		return CLKRST5_INDEX;
+	case 6:
+		return CLKRST6_INDEX;
+	}
+	return -EINVAL;
+}
+
+static void __iomem *u8500_prcc_reset_base(struct u8500_prcc_reset *ur,
+					   unsigned long id)
+{
+	unsigned int prcc_num, index;
+
+	prcc_num = id / PRCC_PERIPHS_PER_CLUSTER;
+	index = prcc_num_to_index(prcc_num);
+
+	if (index >= ARRAY_SIZE(ur->base))
+		return NULL;
+
+	return ur->base[index];
+}
+
+static int u8500_prcc_reset(struct reset_controller_dev *rcdev,
+			    unsigned long id)
+{
+	struct u8500_prcc_reset *ur = to_u8500_prcc_reset(rcdev);
+	void __iomem *base = u8500_prcc_reset_base(ur, id);
+	unsigned int bit = id % PRCC_PERIPHS_PER_CLUSTER;
+
+	pr_debug("PRCC cycle reset id %lu, bit %u\n", id, bit);
+
+	/*
+	 * Assert reset and then release it. The one microsecond
+	 * delay is found in the vendor reference code.
+	 */
+	writel(BIT(bit), base + PRCC_K_SOFTRST_CLEAR);
+	udelay(1);
+	writel(BIT(bit), base + PRCC_K_SOFTRST_SET);
+	udelay(1);
+
+	return 0;
+}
+
+static int u8500_prcc_reset_assert(struct reset_controller_dev *rcdev,
+				   unsigned long id)
+{
+	struct u8500_prcc_reset *ur = to_u8500_prcc_reset(rcdev);
+	void __iomem *base = u8500_prcc_reset_base(ur, id);
+	unsigned int bit = id % PRCC_PERIPHS_PER_CLUSTER;
+
+	pr_debug("PRCC assert reset id %lu, bit %u\n", id, bit);
+	writel(BIT(bit), base + PRCC_K_SOFTRST_CLEAR);
+
+	return 0;
+}
+
+static int u8500_prcc_reset_deassert(struct reset_controller_dev *rcdev,
+				     unsigned long id)
+{
+	struct u8500_prcc_reset *ur = to_u8500_prcc_reset(rcdev);
+	void __iomem *base = u8500_prcc_reset_base(ur, id);
+	unsigned int bit = id % PRCC_PERIPHS_PER_CLUSTER;
+
+	pr_debug("PRCC deassert reset id %lu, bit %u\n", id, bit);
+	writel(BIT(bit), base + PRCC_K_SOFTRST_SET);
+
+	return 0;
+}
+
+static int u8500_prcc_reset_status(struct reset_controller_dev *rcdev,
+				   unsigned long id)
+{
+	struct u8500_prcc_reset *ur = to_u8500_prcc_reset(rcdev);
+	void __iomem *base = u8500_prcc_reset_base(ur, id);
+	unsigned int bit = id % PRCC_PERIPHS_PER_CLUSTER;
+	u32 val;
+
+	pr_debug("PRCC check status on reset line id %lu, bit %u\n", id, bit);
+	val = readl(base + PRCC_K_RST_STATUS);
+
+	/* Active low so return the inverse value of the bit */
+	return !(val & BIT(bit));
+}
+
+static const struct reset_control_ops u8500_prcc_reset_ops = {
+	.reset = u8500_prcc_reset,
+	.assert = u8500_prcc_reset_assert,
+	.deassert = u8500_prcc_reset_deassert,
+	.status = u8500_prcc_reset_status,
+};
+
+static int u8500_prcc_reset_xlate(struct reset_controller_dev *rcdev,
+				  const struct of_phandle_args *reset_spec)
+{
+	unsigned int prcc_num, bit;
+
+	if (reset_spec->args_count != 2)
+		return -EINVAL;
+
+	prcc_num = reset_spec->args[0];
+	bit = reset_spec->args[1];
+
+	if (prcc_num != 1 && prcc_num != 2 && prcc_num != 3 &&
+	    prcc_num != 5 && prcc_num != 6) {
+		pr_err("%s: invalid PRCC %d\n", __func__, prcc_num);
+		return -EINVAL;
+	}
+
+	pr_debug("located reset line %d at PRCC %d bit %d\n",
+		 PRCC_RESET_LINE(prcc_num, bit), prcc_num, bit);
+
+	return PRCC_RESET_LINE(prcc_num, bit);
+}
+
+void u8500_prcc_reset_init(struct device_node *np, struct u8500_prcc_reset *ur)
+{
+	struct reset_controller_dev *rcdev = &ur->rcdev;
+	int ret;
+	int i;
+
+	for (i = 0; i < CLKRST_MAX; i++) {
+		ur->base[i] = ioremap(ur->phy_base[i], SZ_4K);
+		if (!ur->base[i])
+			pr_err("PRCC failed to remap for reset base %d (%08x)\n",
+			       i, ur->phy_base[i]);
+	}
+
+	rcdev->owner = THIS_MODULE;
+	rcdev->ops = &u8500_prcc_reset_ops;
+	rcdev->of_node = np;
+	rcdev->of_reset_n_cells = 2;
+	rcdev->of_xlate = u8500_prcc_reset_xlate;
+
+	ret = reset_controller_register(rcdev);
+	if (ret)
+		pr_err("PRCC failed to register reset controller\n");
+}