[PATCH 1/2] dt-bindings: clock: u8500: Rewrite in YAML and extend

[PATCH 1/2] dt-bindings: clock: u8500: Rewrite in YAML and extend

[Linus Walleij]

This rewrites the ux500/u8500 clock bindings in YAML schema and extends them
with the PRCC reset controller.

The bindings are a bit idiomatic but it just reflects their age, the ux500
platform was used as guinea pig for early device tree conversion of platforms
in 2015. The new subnode for the reset controller follows the pattern of the
old bindings and adds a node with reset-cells for this.

Cc: devicetree@vger.kernel.org
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 .../bindings/clock/stericsson,u8500-clks.yaml | 113 ++++++++++++++++++
 .../devicetree/bindings/clock/ux500.txt       |  64 ----------
 .../reset/stericsson,db8500-prcc-reset.h      |  51 ++++++++
 3 files changed, 164 insertions(+), 64 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml
 delete mode 100644 Documentation/devicetree/bindings/clock/ux500.txt
 create mode 100644 include/dt-bindings/reset/stericsson,db8500-prcc-reset.h

diff --git a/Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml b/Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml
new file mode 100644
index 000000000000..b3eca95299ab
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml
@@ -0,0 +1,113 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/stericsson,u8500-clks.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ST-Ericsson DB8500 (U8500) clocks
+
+maintainers:
+  - Ulf Hansson <ulf.hansson@linaro.org>
+  - Linus Walleij <linus.walleij@linaro.org>
+
+description: While named "U8500 clocks" these clocks are inside the
+  DB8500 digital baseband system-on-chip and its siblings such as
+  DB8520. These bindings consider the clocks present in the SoC
+  itself, not off-chip clocks. There are four different on-chip
+  clocks - RTC (32 kHz), CPU clock (SMP TWD), PRCMU (power reset and
+  control management unit) clocks and PRCC (peripheral reset and
+  clock controller) clocks.
+
+properties:
+  compatible:
+    oneOf:
+      - const: stericsson,u8500-clks
+      - const: stericsson,u8540-clks
+      - const: stericsson,u9540-clks
+
+  reg:
+    items:
+      - description: PRCC 1 register area
+      - description: PRCC 2 register area
+      - description: PRCC 3 register area
+      - description: PRCC 5 register area
+      - description: PRCC 6 register area
+
+  prcmu-clock:
+    description: A subnode with one clock cell for PRCMU (power, reset, control
+      management unit) clocks. The cell indicates which PRCMU clock in the
+      prcmu-clock node the consumer wants to use.
+    type: object
+
+    properties:
+      '#clock-cells':
+        const: 1
+
+    additionalProperties: false
+
+  prcc-periph-clock:
+    description: A subnode with two clock cells for PRCC (peripheral
+      reset and clock controller) peripheral clocks. The first cell indicates
+      which PRCC block the consumer wants to use, possible values are 1, 2, 3,
+      5, 6. The second cell indicates which clock inside the PRCC block it
+      wants, possible values are 0 thru 31.
+    type: object
+
+    properties:
+      '#clock-cells':
+        const: 2
+
+    additionalProperties: false
+
+  prcc-kernel-clock:
+    description: A subnode with two clock cells for PRCC (peripheral reset
+      and clock controller) kernel clocks. The first cell indicates which PRCC
+      block the consumer wants to use, possible values are 1, 2, 3, 5, 6. The
+      second cell indicates which clock inside the PRCC block it wants, possible
+      values are 0 thru 31.
+    type: object
+
+    properties:
+      '#clock-cells':
+        const: 2
+
+    additionalProperties: false
+
+  prcc-reset-controller:
+    description: A subnode with two reset cells for the reset portions of the
+      PRCC (peripheral reset and clock controller). The first cell indicates
+      which PRCC block the consumer wants to use, possible values are 1, 2, 3
+      5 and 6. The second cell indicates which reset line inside the PRCC block
+      it wants to control, possible values are 0 thru 31.
+
+  rtc32k-clock:
+    description: A subnode with zero clock cells for the 32kHz RTC clock.
+    type: object
+
+    properties:
+      '#clock-cells':
+        const: 0
+
+    additionalProperties: false
+
+  smp-twd-clock:
+    description: A subnode for the ARM SMP Timer Watchdog cluster with zero
+      clock cells.
+    type: object
+
+    properties:
+      '#clock-cells':
+        const: 0
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - prcmu-clock
+  - prcc-periph-clock
+  - prcc-kernel-clock
+  - rtc32k-clock
+  - smp-twd-clock
+
+additionalProperties: false
diff --git a/Documentation/devicetree/bindings/clock/ux500.txt b/Documentation/devicetree/bindings/clock/ux500.txt
deleted file mode 100644
index e52bd4b72348..000000000000
--- a/Documentation/devicetree/bindings/clock/ux500.txt
+++ /dev/null
@@ -1,64 +0,0 @@
-Clock bindings for ST-Ericsson Ux500 clocks
-
-Required properties :
-- compatible : shall contain only one of the following:
-  "stericsson,u8500-clks"
-  "stericsson,u8540-clks"
-  "stericsson,u9540-clks"
-- reg : shall contain base register location and length for
-  CLKRST1, 2, 3, 5, and 6 in an array. Note the absence of
-  CLKRST4, which does not exist.
-
-Required subnodes:
-- prcmu-clock: a subnode with one clock cell for PRCMU (power,
-  reset, control unit) clocks. The cell indicates which PRCMU
-  clock in the prcmu-clock node the consumer wants to use.
-- prcc-periph-clock: a subnode with two clock cells for
-  PRCC (programmable reset- and clock controller) peripheral clocks.
-  The first cell indicates which PRCC block the consumer
-  wants to use, possible values are 1, 2, 3, 5, 6. The second
-  cell indicates which clock inside the PRCC block it wants,
-  possible values are 0 thru 31.
-- prcc-kernel-clock: a subnode with two clock cells for
-  PRCC (programmable reset- and clock controller) kernel clocks
-  The first cell indicates which PRCC block the consumer
-  wants to use, possible values are 1, 2, 3, 5, 6. The second
-  cell indicates which clock inside the PRCC block it wants,
-  possible values are 0 thru 31.
-- rtc32k-clock: a subnode with zero clock cells for the 32kHz
-  RTC clock.
-- smp-twd-clock: a subnode for the ARM SMP Timer Watchdog cluster
-  with zero clock cells.
-
-Example:
-
-clocks {
-	compatible = "stericsson,u8500-clks";
-	/*
-	 * Registers for the CLKRST block on peripheral
-	 * groups 1, 2, 3, 5, 6,
-	 */
-	reg = <0x8012f000 0x1000>, <0x8011f000 0x1000>,
-	    <0x8000f000 0x1000>, <0xa03ff000 0x1000>,
-	    <0xa03cf000 0x1000>;
-
-	prcmu_clk: prcmu-clock {
-		#clock-cells = <1>;
-	};
-
-	prcc_pclk: prcc-periph-clock {
-		#clock-cells = <2>;
-	};
-
-	prcc_kclk: prcc-kernel-clock {
-		#clock-cells = <2>;
-	};
-
-	rtc_clk: rtc32k-clock {
-		#clock-cells = <0>;
-	};
-
-	smp_twd_clk: smp-twd-clock {
-		#clock-cells = <0>;
-	};
-};
diff --git a/include/dt-bindings/reset/stericsson,db8500-prcc-reset.h b/include/dt-bindings/reset/stericsson,db8500-prcc-reset.h
new file mode 100644
index 000000000000..ea906896c70f
--- /dev/null
+++ b/include/dt-bindings/reset/stericsson,db8500-prcc-reset.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _DT_BINDINGS_STE_PRCC_RESET
+#define _DT_BINDINGS_STE_PRCC_RESET
+
+#define DB8500_PRCC_1				1
+#define DB8500_PRCC_2				2
+#define DB8500_PRCC_3				3
+#define DB8500_PRCC_6				6
+
+/* Reset lines on PRCC 1 */
+#define DB8500_PRCC_1_RESET_UART0		0
+#define DB8500_PRCC_1_RESET_UART1		1
+#define DB8500_PRCC_1_RESET_I2C1		2
+#define DB8500_PRCC_1_RESET_MSP0		3
+#define DB8500_PRCC_1_RESET_MSP1		4
+#define DB8500_PRCC_1_RESET_SDI0		5
+#define DB8500_PRCC_1_RESET_I2C2		6
+#define DB8500_PRCC_1_RESET_SPI3		7
+#define DB8500_PRCC_1_RESET_SLIMBUS0		8
+#define DB8500_PRCC_1_RESET_I2C4		9
+#define DB8500_PRCC_1_RESET_MSP3		10
+#define DB8500_PRCC_1_RESET_PER_MSP3		11
+#define DB8500_PRCC_1_RESET_PER_MSP1		12
+#define DB8500_PRCC_1_RESET_PER_MSP0		13
+#define DB8500_PRCC_1_RESET_PER_SLIMBUS		14
+
+/* Reset lines on PRCC 2 */
+#define DB8500_PRCC_2_RESET_I2C3		0
+#define DB8500_PRCC_2_RESET_PWL			1
+#define DB8500_PRCC_2_RESET_SDI4		2
+#define DB8500_PRCC_2_RESET_MSP2		3
+#define DB8500_PRCC_2_RESET_SDI1		4
+#define DB8500_PRCC_2_RESET_SDI3		5
+#define DB8500_PRCC_2_RESET_HSIRX		6
+#define DB8500_PRCC_2_RESET_HSITX		7
+#define DB8500_PRCC_1_RESET_PER_MSP2		8
+
+/* Reset lines on PRCC 3 */
+#define DB8500_PRCC_3_RESET_SSP0		1
+#define DB8500_PRCC_3_RESET_SSP1		2
+#define DB8500_PRCC_3_RESET_I2C0		3
+#define DB8500_PRCC_3_RESET_SDI2		4
+#define DB8500_PRCC_3_RESET_SKE			5
+#define DB8500_PRCC_3_RESET_UART2		6
+#define DB8500_PRCC_3_RESET_SDI5		7
+
+/* Reset lines on PRCC 6 */
+#define DB8500_PRCC_3_RESET_RNG			0
+
+#endif
-- 
2.31.1

[PATCH 2/2] clk: ux500: Add driver for the reset portions of PRCC

[Linus Walleij]

The Ux500 PRCC (peripheral reset and clock controller) can also
control reset of the IP blocks, not just clocks. As the PRCC is probed
as a clock controller and we have other platforms implementing combined
clock and reset controllers, follow this pattern and implement the PRCC
rest controller as part of the clock driver.

The reset controller needs to be selected from the machine as Ux500 has
traditionally selected its mandatory subsystem prerequisites from there.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 arch/arm/mach-ux500/Kconfig      |   1 +
 drivers/clk/ux500/Makefile       |   3 +
 drivers/clk/ux500/prcc.h         |  36 +++++++
 drivers/clk/ux500/reset-prcc.c   | 159 +++++++++++++++++++++++++++++++
 drivers/clk/ux500/reset-prcc.h   |  22 +++++
 drivers/clk/ux500/u8500_of_clk.c |  32 ++++---
 6 files changed, 240 insertions(+), 13 deletions(-)
 create mode 100644 drivers/clk/ux500/prcc.h
 create mode 100644 drivers/clk/ux500/reset-prcc.c
 create mode 100644 drivers/clk/ux500/reset-prcc.h

diff --git a/arch/arm/mach-ux500/Kconfig b/arch/arm/mach-ux500/Kconfig
index c1086ebe0050..24ed7f4a87a4 100644
--- a/arch/arm/mach-ux500/Kconfig
+++ b/arch/arm/mach-ux500/Kconfig
@@ -29,6 +29,7 @@ menuconfig ARCH_U8500
 	select REGULATOR_DB8500_PRCMU
 	select REGULATOR_FIXED_VOLTAGE
 	select SOC_BUS
+	select RESET_CONTROLLER
 	help
 	  Support for ST-Ericsson's Ux500 architecture
 
diff --git a/drivers/clk/ux500/Makefile b/drivers/clk/ux500/Makefile
index 53fd29002401..c29b83df403e 100644
--- a/drivers/clk/ux500/Makefile
+++ b/drivers/clk/ux500/Makefile
@@ -8,6 +8,9 @@ obj-y += clk-prcc.o
 obj-y += clk-prcmu.o
 obj-y += clk-sysctrl.o
 
+# Reset control
+obj-y += reset-prcc.o
+
 # Clock definitions
 obj-y += u8500_of_clk.o
 
diff --git a/drivers/clk/ux500/prcc.h b/drivers/clk/ux500/prcc.h
new file mode 100644
index 000000000000..bf978cace563
--- /dev/null
+++ b/drivers/clk/ux500/prcc.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __PRCC_H
+#define __PRCC_H
+
+#define PRCC_NUM_PERIPH_CLUSTERS 6
+#define PRCC_PERIPHS_PER_CLUSTER 32
+
+/* CLKRST4 is missing making it hard to index things */
+enum clkrst_index {
+	CLKRST1_INDEX = 0,
+	CLKRST2_INDEX,
+	CLKRST3_INDEX,
+	CLKRST5_INDEX,
+	CLKRST6_INDEX,
+	CLKRST_MAX,
+};
+
+static inline 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;
+}
+
+#endif
diff --git a/drivers/clk/ux500/reset-prcc.c b/drivers/clk/ux500/reset-prcc.c
new file mode 100644
index 000000000000..91f9f1942fd9
--- /dev/null
+++ b/drivers/clk/ux500/reset-prcc.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#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 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 %d\n", id, bit);
+
+	/* Assert reset and then release it */
+	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 %d\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 %d\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 %d\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->nr_resets = 256; /* Only used with simple xlate */
+	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");
+}
diff --git a/drivers/clk/ux500/reset-prcc.h b/drivers/clk/ux500/reset-prcc.h
new file mode 100644
index 000000000000..8bdc6df23d14
--- /dev/null
+++ b/drivers/clk/ux500/reset-prcc.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __RESET_PRCC_H
+#define __RESET_PRCC_H
+
+#include <linux/reset-controller.h>
+#include <linux/io.h>
+
+/**
+ * struct u8500_prcc_reset - U8500 PRCC reset controller state
+ * @rcdev: reset controller device
+ * @bases: the PRCC bases
+ */
+struct u8500_prcc_reset {
+	struct reset_controller_dev rcdev;
+	u32 phy_base[CLKRST_MAX];
+	void __iomem *base[CLKRST_MAX];
+};
+
+void u8500_prcc_reset_init(struct device_node *np, struct u8500_prcc_reset *ur);
+
+#endif
diff --git a/drivers/clk/ux500/u8500_of_clk.c b/drivers/clk/ux500/u8500_of_clk.c
index 0aedd42fad52..330d45ab27a9 100644
--- a/drivers/clk/ux500/u8500_of_clk.c
+++ b/drivers/clk/ux500/u8500_of_clk.c
@@ -10,10 +10,10 @@
 #include <linux/of_address.h>
 #include <linux/clk-provider.h>
 #include <linux/mfd/dbx500-prcmu.h>
-#include "clk.h"
 
-#define PRCC_NUM_PERIPH_CLUSTERS 6
-#define PRCC_PERIPHS_PER_CLUSTER 32
+#include "clk.h"
+#include "prcc.h"
+#include "reset-prcc.h"
 
 static struct clk *prcmu_clk[PRCMU_NUM_CLKS];
 static struct clk *prcc_pclk[(PRCC_NUM_PERIPH_CLUSTERS + 1) * PRCC_PERIPHS_PER_CLUSTER];
@@ -46,16 +46,6 @@ static struct clk *ux500_twocell_get(struct of_phandle_args *clkspec,
 	return PRCC_SHOW(clk_data, base, bit);
 }
 
-/* CLKRST4 is missing making it hard to index things */
-enum clkrst_index {
-	CLKRST1_INDEX = 0,
-	CLKRST2_INDEX,
-	CLKRST3_INDEX,
-	CLKRST5_INDEX,
-	CLKRST6_INDEX,
-	CLKRST_MAX,
-};
-
 static void u8500_clk_init(struct device_node *np)
 {
 	struct prcmu_fw_version *fw_version;
@@ -63,8 +53,20 @@ static void u8500_clk_init(struct device_node *np)
 	const char *sgaclk_parent = NULL;
 	struct clk *clk, *rtc_clk, *twd_clk;
 	u32 bases[CLKRST_MAX];
+	struct u8500_prcc_reset *rstc;
 	int i;
 
+	/*
+	 * We allocate the reset controller here so that we can fill in the
+	 * base addresses properly and pass to the reset controller init
+	 * function later on.
+	 */
+	rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
+	if (!rstc) {
+		pr_err("could not allocate reset controller\n");
+		return;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(bases); i++) {
 		struct resource r;
 
@@ -73,6 +75,7 @@ static void u8500_clk_init(struct device_node *np)
 			pr_err("failed to get CLKRST %d base address\n",
 			       i + 1);
 		bases[i] = r.start;
+		rstc->phy_base[i] = r.start;
 	}
 
 	/* Clock sources */
@@ -562,6 +565,9 @@ static void u8500_clk_init(struct device_node *np)
 
 		if (of_node_name_eq(child, "smp-twd-clock"))
 			of_clk_add_provider(child, of_clk_src_simple_get, twd_clk);
+
+		if (of_node_name_eq(child, "prcc-reset-controller"))
+			u8500_prcc_reset_init(child, rstc);
 	}
 }
 CLK_OF_DECLARE(u8500_clks, "stericsson,u8500-clks", u8500_clk_init);
-- 
2.31.1

Re: [PATCH 1/2] dt-bindings: clock: u8500: Rewrite in YAML and extend

[Rob Herring]

On Sun, Jun 20, 2021 at 01:05:25AM +0200, Linus Walleij wrote:
> This rewrites the ux500/u8500 clock bindings in YAML schema and extends them
> with the PRCC reset controller.
> 
> The bindings are a bit idiomatic but it just reflects their age, the ux500
> platform was used as guinea pig for early device tree conversion of platforms
> in 2015. The new subnode for the reset controller follows the pattern of the
> old bindings and adds a node with reset-cells for this.
> 
> Cc: devicetree@vger.kernel.org
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  .../bindings/clock/stericsson,u8500-clks.yaml | 113 ++++++++++++++++++
>  .../devicetree/bindings/clock/ux500.txt       |  64 ----------
>  .../reset/stericsson,db8500-prcc-reset.h      |  51 ++++++++
>  3 files changed, 164 insertions(+), 64 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml
>  delete mode 100644 Documentation/devicetree/bindings/clock/ux500.txt
>  create mode 100644 include/dt-bindings/reset/stericsson,db8500-prcc-reset.h
> 
> diff --git a/Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml b/Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml
> new file mode 100644
> index 000000000000..b3eca95299ab
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml
> @@ -0,0 +1,113 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/stericsson,u8500-clks.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ST-Ericsson DB8500 (U8500) clocks
> +
> +maintainers:
> +  - Ulf Hansson <ulf.hansson@linaro.org>
> +  - Linus Walleij <linus.walleij@linaro.org>
> +
> +description: While named "U8500 clocks" these clocks are inside the
> +  DB8500 digital baseband system-on-chip and its siblings such as
> +  DB8520. These bindings consider the clocks present in the SoC
> +  itself, not off-chip clocks. There are four different on-chip
> +  clocks - RTC (32 kHz), CPU clock (SMP TWD), PRCMU (power reset and
> +  control management unit) clocks and PRCC (peripheral reset and
> +  clock controller) clocks.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: stericsson,u8500-clks
> +      - const: stericsson,u8540-clks
> +      - const: stericsson,u9540-clks

enum instead of oneOf+const

> +
> +  reg:
> +    items:
> +      - description: PRCC 1 register area
> +      - description: PRCC 2 register area
> +      - description: PRCC 3 register area
> +      - description: PRCC 5 register area
> +      - description: PRCC 6 register area
> +
> +  prcmu-clock:
> +    description: A subnode with one clock cell for PRCMU (power, reset, control
> +      management unit) clocks. The cell indicates which PRCMU clock in the
> +      prcmu-clock node the consumer wants to use.
> +    type: object
> +
> +    properties:
> +      '#clock-cells':
> +        const: 1
> +
> +    additionalProperties: false
> +
> +  prcc-periph-clock:
> +    description: A subnode with two clock cells for PRCC (peripheral
> +      reset and clock controller) peripheral clocks. The first cell indicates
> +      which PRCC block the consumer wants to use, possible values are 1, 2, 3,
> +      5, 6. The second cell indicates which clock inside the PRCC block it
> +      wants, possible values are 0 thru 31.
> +    type: object
> +
> +    properties:
> +      '#clock-cells':
> +        const: 2
> +
> +    additionalProperties: false
> +
> +  prcc-kernel-clock:
> +    description: A subnode with two clock cells for PRCC (peripheral reset
> +      and clock controller) kernel clocks. The first cell indicates which PRCC
> +      block the consumer wants to use, possible values are 1, 2, 3, 5, 6. The
> +      second cell indicates which clock inside the PRCC block it wants, possible
> +      values are 0 thru 31.
> +    type: object
> +
> +    properties:
> +      '#clock-cells':
> +        const: 2
> +
> +    additionalProperties: false
> +
> +  prcc-reset-controller:
> +    description: A subnode with two reset cells for the reset portions of the
> +      PRCC (peripheral reset and clock controller). The first cell indicates
> +      which PRCC block the consumer wants to use, possible values are 1, 2, 3
> +      5 and 6. The second cell indicates which reset line inside the PRCC block
> +      it wants to control, possible values are 0 thru 31.

type: object ?

Needs #reset-cells?

Though, it doesn't appear to be used, so drop?

> +
> +  rtc32k-clock:
> +    description: A subnode with zero clock cells for the 32kHz RTC clock.
> +    type: object
> +
> +    properties:
> +      '#clock-cells':
> +        const: 0
> +
> +    additionalProperties: false
> +
> +  smp-twd-clock:
> +    description: A subnode for the ARM SMP Timer Watchdog cluster with zero
> +      clock cells.
> +    type: object
> +
> +    properties:
> +      '#clock-cells':
> +        const: 0
> +
> +    additionalProperties: false
> +
> +required:
> +  - compatible
> +  - reg
> +  - prcmu-clock
> +  - prcc-periph-clock
> +  - prcc-kernel-clock
> +  - rtc32k-clock
> +  - smp-twd-clock
> +
> +additionalProperties: false

Re: [PATCH 2/2] clk: ux500: Add driver for the reset portions of PRCC

[Stephen Boyd]

Quoting Linus Walleij (2021-06-19 16:05:26)
> The Ux500 PRCC (peripheral reset and clock controller) can also
> control reset of the IP blocks, not just clocks. As the PRCC is probed
> as a clock controller and we have other platforms implementing combined
> clock and reset controllers, follow this pattern and implement the PRCC
> rest controller as part of the clock driver.
> 
> The reset controller needs to be selected from the machine as Ux500 has
> traditionally selected its mandatory subsystem prerequisites from there.
> 
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  arch/arm/mach-ux500/Kconfig      |   1 +
>  drivers/clk/ux500/Makefile       |   3 +
>  drivers/clk/ux500/prcc.h         |  36 +++++++
>  drivers/clk/ux500/reset-prcc.c   | 159 +++++++++++++++++++++++++++++++
>  drivers/clk/ux500/reset-prcc.h   |  22 +++++
>  drivers/clk/ux500/u8500_of_clk.c |  32 ++++---
>  6 files changed, 240 insertions(+), 13 deletions(-)
>  create mode 100644 drivers/clk/ux500/prcc.h
>  create mode 100644 drivers/clk/ux500/reset-prcc.c
>  create mode 100644 drivers/clk/ux500/reset-prcc.h
> 
> diff --git a/arch/arm/mach-ux500/Kconfig b/arch/arm/mach-ux500/Kconfig
> index c1086ebe0050..24ed7f4a87a4 100644
> --- a/arch/arm/mach-ux500/Kconfig
> +++ b/arch/arm/mach-ux500/Kconfig
> @@ -29,6 +29,7 @@ menuconfig ARCH_U8500
>         select REGULATOR_DB8500_PRCMU
>         select REGULATOR_FIXED_VOLTAGE
>         select SOC_BUS
> +       select RESET_CONTROLLER

Please Cc Philipp Zabel <p.zabel@pengutronix.de> for reset controller
things.