On i.MX8MP, there is a new type of IP which is called BLK_CTRL in
RM and usually is comprised of some GPRs that are considered too
generic to be part of any dedicated IP from that specific subsystem.

In general, some of the GPRs have some clock bits, some have reset bits,
so in order to be able to use the imx clock API, this needs to be
in a clock driver. From there it can use the reset controller API and
leave the rest to the syscon.

This driver is intended to work with the following BLK_CTRL IPs found in
i.MX8MP (but it might be reused by the future i.MX platforms that
have this kind of IP in their design):
 - Audio
 - Media
 - HDMI

Signed-off-by: Abel Vesa <redacted>
---
 drivers/clk/imx/Makefile       |   2 +-
 drivers/clk/imx/clk-blk-ctrl.c | 327 +++++++++++++++++++++++++++++++++++++++++
 drivers/clk/imx/clk-blk-ctrl.h |  81 ++++++++++
 3 files changed, 409 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/imx/clk-blk-ctrl.c
 create mode 100644 drivers/clk/imx/clk-blk-ctrl.h

diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile
index 928f874c..7afe1df 100644
--- a/drivers/clk/imx/Makefile
+++ b/drivers/clk/imx/Makefile

@@ -27,7 +27,7 @@ obj-$(CONFIG_MXC_CLK_SCU) += \
 
 obj-$(CONFIG_CLK_IMX8MM) += clk-imx8mm.o
 obj-$(CONFIG_CLK_IMX8MN) += clk-imx8mn.o
-obj-$(CONFIG_CLK_IMX8MP) += clk-imx8mp.o
+obj-$(CONFIG_CLK_IMX8MP) += clk-imx8mp.o clk-blk-ctrl.o
 obj-$(CONFIG_CLK_IMX8MQ) += clk-imx8mq.o
 obj-$(CONFIG_CLK_IMX8QXP) += clk-imx8qxp.o clk-imx8qxp-lpcg.o
 

diff --git a/drivers/clk/imx/clk-blk-ctrl.c b/drivers/clk/imx/clk-blk-ctrl.c
new file mode 100644
index 00000000..1672646
--- /dev/null
+++ b/drivers/clk/imx/clk-blk-ctrl.c

@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2020 NXP.
+ */
+
+#include <linux/clk.h>
+#include <linux/reset-controller.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "clk.h"
+#include "clk-blk-ctrl.h"
+
+struct reset_hw {
+	u32 offset;
+	u32 shift;
+	u32 mask;
+	bool asserted;
+};
+
+struct pm_safekeep_info {
+	uint32_t *regs_values;
+	uint32_t *regs_offsets;
+	uint32_t regs_num;
+};
+
+struct imx_blk_ctrl_drvdata {
+	void __iomem *base;
+	struct reset_controller_dev rcdev;
+	struct reset_hw *rst_hws;
+	struct pm_safekeep_info pm_info;
+
+	spinlock_t lock;
+};
+
+static int imx_blk_ctrl_reset_set(struct reset_controller_dev *rcdev,
+				  unsigned long id, bool assert)
+{
+	struct imx_blk_ctrl_drvdata *drvdata = container_of(rcdev,
+			struct imx_blk_ctrl_drvdata, rcdev);
+	unsigned int offset = drvdata->rst_hws[id].offset;
+	unsigned int shift = drvdata->rst_hws[id].shift;
+	unsigned int mask = drvdata->rst_hws[id].mask;
+	void __iomem *reg_addr = drvdata->base + offset;
+	unsigned long flags;
+	unsigned int asserted_before = 0, asserted_after = 0;
+	u32 reg;
+	int i;
+
+	spin_lock_irqsave(&drvdata->lock, flags);
+
+	for (i = 0; i < drvdata->rcdev.nr_resets; i++)
+		if (drvdata->rst_hws[i].asserted)
+			asserted_before++;
+
+	if (asserted_before == 0 && assert)
+		pm_runtime_get(rcdev->dev);