Merge tag 'soc-ep93xx-dt-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull SoC update from Arnd Bergmann:
 "Convert ep93xx to devicetree

  This concludes a long journey towards replacing the old board files
  with devictree description on the Cirrus Logic EP93xx platform.

  Nikita Shubin has been working on this for a long time, for details
  see the last post on

    https://lore.kernel.org/lkml/20240909-ep93xx-v12-0-e86ab2423d4b@maquefel.me/"

* tag 'soc-ep93xx-dt-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (47 commits)
  dt-bindings: gpio: ep9301: Add missing "#interrupt-cells" to examples
  MAINTAINERS: Update EP93XX ARM ARCHITECTURE maintainer
  soc: ep93xx: drop reference to removed EP93XX_SOC_COMMON config
  net: cirrus: use u8 for addr to calm down sparse
  dmaengine: cirrus: use snprintf() to calm down gcc 13.3.0
  dmaengine: ep93xx: Fix a NULL vs IS_ERR() check in probe()
  pinctrl: ep93xx: Fix raster pins typo
  spi: ep93xx: update kerneldoc comments for ep93xx_spi
  clk: ep93xx: Fix off by one in ep93xx_div_recalc_rate()
  clk: ep93xx: add module license
  dmaengine: cirrus: remove platform code
  ASoC: cirrus: edb93xx: Delete driver
  ARM: ep93xx: soc: drop defines
  ARM: ep93xx: delete all boardfiles
  ata: pata_ep93xx: remove legacy pinctrl use
  pwm: ep93xx: drop legacy pinctrl
  ARM: ep93xx: DT for the Cirrus ep93xx SoC platforms
  ARM: dts: ep93xx: Add EDB9302 DT
  ARM: dts: ep93xx: add ts7250 board
  ARM: dts: add Cirrus EP93XX SoC .dtsi
  ...

5 files changed, 273 insertions, 0 deletions

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index 5d924e946507..6a8daeb8c4b9 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -7,6 +7,7 @@ source "drivers/soc/aspeed/Kconfig"
 source "drivers/soc/atmel/Kconfig"
 source "drivers/soc/bcm/Kconfig"
 source "drivers/soc/canaan/Kconfig"
+source "drivers/soc/cirrus/Kconfig"
 source "drivers/soc/fsl/Kconfig"
 source "drivers/soc/fujitsu/Kconfig"
 source "drivers/soc/hisilicon/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 56f476a12847..2037a8695cb2 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -8,6 +8,7 @@ obj-y				+= aspeed/
 obj-$(CONFIG_ARCH_AT91)		+= atmel/
 obj-y				+= bcm/
 obj-$(CONFIG_ARCH_CANAAN)	+= canaan/
+obj-$(CONFIG_EP93XX_SOC)        += cirrus/
 obj-$(CONFIG_ARCH_DOVE)		+= dove/
 obj-$(CONFIG_MACH_DOVE)		+= dove/
 obj-y				+= fsl/
diff --git a/drivers/soc/cirrus/Kconfig b/drivers/soc/cirrus/Kconfig
new file mode 100644
index 000000000000..d8b3b1e68998
--- /dev/null
+++ b/drivers/soc/cirrus/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+if ARCH_EP93XX
+
+config EP93XX_SOC
+	bool "Cirrus EP93xx chips SoC"
+	select SOC_BUS
+	select AUXILIARY_BUS
+	default y
+	help
+	  Enable support SoC for Cirrus EP93xx chips.
+
+	  Cirrus EP93xx chips have several swlocked registers,
+	  this driver provides locked access for reset, pinctrl
+	  and clk devices implemented as auxiliary devices.
+
+endif
diff --git a/drivers/soc/cirrus/Makefile b/drivers/soc/cirrus/Makefile
new file mode 100644
index 000000000000..9e6608b67f76
--- /dev/null
+++ b/drivers/soc/cirrus/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y	+= soc-ep93xx.o
diff --git a/drivers/soc/cirrus/soc-ep93xx.c b/drivers/soc/cirrus/soc-ep93xx.c
new file mode 100644
index 000000000000..3e79b3b13aef
--- /dev/null
+++ b/drivers/soc/cirrus/soc-ep93xx.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SoC driver for Cirrus EP93xx chips.
+ * Copyright (C) 2022 Nikita Shubin <nikita.shubin@maquefel.me>
+ *
+ * Based on a rewrite of arch/arm/mach-ep93xx/core.c
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ * Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org>
+ *
+ * Thanks go to Michael Burian and Ray Lehtiniemi for their key
+ * role in the ep93xx Linux community.
+ */
+
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/init.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/sys_soc.h>
+
+#include <linux/soc/cirrus/ep93xx.h>
+
+#define EP93XX_SYSCON_DEVCFG		0x80
+
+#define EP93XX_SWLOCK_MAGICK		0xaa
+#define EP93XX_SYSCON_SWLOCK		0xc0
+#define EP93XX_SYSCON_SYSCFG		0x9c
+#define EP93XX_SYSCON_SYSCFG_REV_MASK	GENMASK(31, 28)
+#define EP93XX_SYSCON_SYSCFG_REV_SHIFT	28
+
+struct ep93xx_map_info {
+	spinlock_t lock;
+	void __iomem *base;
+	struct regmap *map;
+};
+
+/*
+ * EP93xx System Controller software locked register write
+ *
+ * Logic safeguards are included to condition the control signals for
+ * power connection to the matrix to prevent part damage. In addition, a
+ * software lock register is included that must be written with 0xAA
+ * before each register write to change the values of the four switch
+ * matrix control registers.
+ */
+static void ep93xx_regmap_write(struct regmap *map, spinlock_t *lock,
+				 unsigned int reg, unsigned int val)
+{
+	guard(spinlock_irqsave)(lock);
+
+	regmap_write(map, EP93XX_SYSCON_SWLOCK, EP93XX_SWLOCK_MAGICK);
+	regmap_write(map, reg, val);
+}
+
+static void ep93xx_regmap_update_bits(struct regmap *map, spinlock_t *lock,
+				      unsigned int reg, unsigned int mask,
+				      unsigned int val)
+{
+	guard(spinlock_irqsave)(lock);
+
+	regmap_write(map, EP93XX_SYSCON_SWLOCK, EP93XX_SWLOCK_MAGICK);
+	/* force write is required to clear swlock if no changes are made */
+	regmap_update_bits_base(map, reg, mask, val, NULL, false, true);
+}
+
+static void ep93xx_unregister_adev(void *_adev)
+{
+	struct auxiliary_device *adev = _adev;
+
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+}
+
+static void ep93xx_adev_release(struct device *dev)
+{
+	struct auxiliary_device *adev = to_auxiliary_dev(dev);
+	struct ep93xx_regmap_adev *rdev = to_ep93xx_regmap_adev(adev);
+
+	kfree(rdev);
+}
+
+static struct auxiliary_device __init *ep93xx_adev_alloc(struct device *parent,
+							 const char *name,
+							 struct ep93xx_map_info *info)
+{
+	struct ep93xx_regmap_adev *rdev __free(kfree) = NULL;
+	struct auxiliary_device *adev;
+	int ret;
+
+	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
+	if (!rdev)
+		return ERR_PTR(-ENOMEM);
+
+	rdev->map = info->map;
+	rdev->base = info->base;
+	rdev->lock = &info->lock;
+	rdev->write = ep93xx_regmap_write;
+	rdev->update_bits = ep93xx_regmap_update_bits;
+
+	adev = &rdev->adev;
+	adev->name = name;
+	adev->dev.parent = parent;
+	adev->dev.release = ep93xx_adev_release;
+
+	ret = auxiliary_device_init(adev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &no_free_ptr(rdev)->adev;
+}
+
+static int __init ep93xx_controller_register(struct device *parent, const char *name,
+					     struct ep93xx_map_info *info)
+{
+	struct auxiliary_device *adev;
+	int ret;
+
+	adev = ep93xx_adev_alloc(parent, name, info);
+	if (IS_ERR(adev))
+		return PTR_ERR(adev);
+
+	ret = auxiliary_device_add(adev);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ret;
+	}
+
+	return devm_add_action_or_reset(parent, ep93xx_unregister_adev, adev);
+}
+
+static unsigned int __init ep93xx_soc_revision(struct regmap *map)
+{
+	unsigned int val;
+
+	regmap_read(map, EP93XX_SYSCON_SYSCFG, &val);
+	val &= EP93XX_SYSCON_SYSCFG_REV_MASK;
+	val >>= EP93XX_SYSCON_SYSCFG_REV_SHIFT;
+	return val;
+}
+
+static const char __init *ep93xx_get_soc_rev(unsigned int rev)
+{
+	switch (rev) {
+	case EP93XX_CHIP_REV_D0:
+		return "D0";
+	case EP93XX_CHIP_REV_D1:
+		return "D1";
+	case EP93XX_CHIP_REV_E0:
+		return "E0";
+	case EP93XX_CHIP_REV_E1:
+		return "E1";
+	case EP93XX_CHIP_REV_E2:
+		return "E2";
+	default:
+		return "unknown";
+	}
+}
+
+static const char *pinctrl_names[] __initconst = {
+	"pinctrl-ep9301",	/* EP93XX_9301_SOC */
+	"pinctrl-ep9307",	/* EP93XX_9307_SOC */
+	"pinctrl-ep9312",	/* EP93XX_9312_SOC */
+};
+
+static int __init ep93xx_syscon_probe(struct platform_device *pdev)
+{
+	enum ep93xx_soc_model model;
+	struct ep93xx_map_info *map_info;
+	struct soc_device_attribute *attrs;
+	struct soc_device *soc_dev;
+	struct device *dev = &pdev->dev;
+	struct regmap *map;
+	void __iomem *base;
+	unsigned int rev;
+	int ret;
+
+	model = (enum ep93xx_soc_model)(uintptr_t)device_get_match_data(dev);
+
+	map = device_node_to_regmap(dev->of_node);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	attrs = devm_kzalloc(dev, sizeof(*attrs), GFP_KERNEL);
+	if (!attrs)
+		return -ENOMEM;
+
+	rev = ep93xx_soc_revision(map);
+
+	attrs->machine = of_flat_dt_get_machine_name();
+	attrs->family = "Cirrus Logic EP93xx";
+	attrs->revision = ep93xx_get_soc_rev(rev);
+
+	soc_dev = soc_device_register(attrs);
+	if (IS_ERR(soc_dev))
+		return PTR_ERR(soc_dev);
+
+	map_info = devm_kzalloc(dev, sizeof(*map_info), GFP_KERNEL);
+	if (!map_info)
+		return -ENOMEM;
+
+	spin_lock_init(&map_info->lock);
+	map_info->map = map;
+	map_info->base = base;
+
+	ret = ep93xx_controller_register(dev, pinctrl_names[model], map_info);
+	if (ret)
+		dev_err(dev, "registering pinctrl controller failed\n");
+
+	/*
+	 * EP93xx SSP clock rate was doubled in version E2. For more information
+	 * see section 6 "2x SSP (Synchronous Serial Port) Clock – Revision E2 only":
+	 *     http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
+	 */
+	if (rev == EP93XX_CHIP_REV_E2)
+		ret = ep93xx_controller_register(dev, "clk-ep93xx.e2", map_info);
+	else
+		ret = ep93xx_controller_register(dev, "clk-ep93xx", map_info);
+	if (ret)
+		dev_err(dev, "registering clock controller failed\n");
+
+	ret = ep93xx_controller_register(dev, "reset-ep93xx", map_info);
+	if (ret)
+		dev_err(dev, "registering reset controller failed\n");
+
+	return 0;
+}
+
+static const struct of_device_id ep9301_syscon_of_device_ids[] = {
+	{ .compatible	= "cirrus,ep9301-syscon", .data = (void *)EP93XX_9301_SOC },
+	{ .compatible	= "cirrus,ep9302-syscon", .data = (void *)EP93XX_9301_SOC },
+	{ .compatible	= "cirrus,ep9307-syscon", .data = (void *)EP93XX_9307_SOC },
+	{ .compatible	= "cirrus,ep9312-syscon", .data = (void *)EP93XX_9312_SOC },
+	{ .compatible	= "cirrus,ep9315-syscon", .data = (void *)EP93XX_9312_SOC },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver ep9301_syscon_driver = {
+	.driver = {
+		.name = "ep9301-syscon",
+		.of_match_table = ep9301_syscon_of_device_ids,
+	},
+};
+builtin_platform_driver_probe(ep9301_syscon_driver, ep93xx_syscon_probe);