@@ -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"
@@ -8,6 +8,7 @@ obj-y += aspeed/
obj-$(CONFIG_ARCH_AT91) += atmel/
obj-y += bcm/
obj-$(CONFIG_SOC_CANAAN) += canaan/
+obj-$(CONFIG_EP93XX_SOC) += cirrus/
obj-$(CONFIG_ARCH_DOVE) += dove/
obj-$(CONFIG_MACH_DOVE) += dove/
obj-y += fsl/
new file mode 100644
@@ -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 if !EP93XX_SOC_COMMON
+ 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
new file mode 100644
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y += soc-ep93xx.o
new file mode 100644
@@ -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);