airoha: Add new target platform

Airoha is a new ARM platform based on Cortex-A53 which has recently been
merged into linux-next.

Due to BootROM limitations on this platform, the Cortex-A53 can't run in
Aarch64 mode and code must be compiled for 32-Bit ARM.

This support is based mostly on those linux-next commits backported
for kernel 5.15.

Patches:
1 - platform support = linux-next
2 - clock driver = linux-next
3 - gpio driver = linux-next
4 - linux,usable-memory-range dts support = linux-next
5 - mtd spinand driver
6 - spi driver
7 - pci driver (kconfig only, uses mediatek PCI) = linux-next

Still missing:
- Ethernet driver
- Sysupgrade support

A.t.m there exists one subtarget EN7523 with only one evaluation
board.

The initramfs can be run with the following commands from u-boot:
-
u-boot> setenv bootfile \
	openwrt-airoha-airoha_en7523-evb-initramfs-kernel.bin
u-boot> tftpboot
u-boot> bootm 0x81800000
-

Signed-off-by: Daniel Danzberger <daniel@dd-wrt.com>

5 files changed, 523 insertions, 0 deletions

diff --git a/target/linux/airoha/files/arch/arm/mach-airoha/Makefile b/target/linux/airoha/files/arch/arm/mach-airoha/Makefile
new file mode 100644
index 0000000000..a5857d0d02
--- /dev/null
+++ b/target/linux/airoha/files/arch/arm/mach-airoha/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y			+= airoha.o
diff --git a/target/linux/airoha/files/arch/arm/mach-airoha/airoha.c b/target/linux/airoha/files/arch/arm/mach-airoha/airoha.c
new file mode 100644
index 0000000000..ea23b5abb4
--- /dev/null
+++ b/target/linux/airoha/files/arch/arm/mach-airoha/airoha.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Device Tree support for Airoha SoCs
+ *
+ * Copyright (c) 2022 Felix Fietkau <nbd@nbd.name>
+ */
+#include <asm/mach/arch.h>
+
+static const char * const airoha_board_dt_compat[] = {
+	"airoha,en7523",
+	NULL,
+};
+
+DT_MACHINE_START(MEDIATEK_DT, "Airoha Cortex-A53 (Device Tree)")
+	.dt_compat	= airoha_board_dt_compat,
+MACHINE_END
diff --git a/target/linux/airoha/files/drivers/clk/clk-en7523.c b/target/linux/airoha/files/drivers/clk/clk-en7523.c
new file mode 100644
index 0000000000..29f0126cbd
--- /dev/null
+++ b/target/linux/airoha/files/drivers/clk/clk-en7523.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/delay.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/clock/en7523-clk.h>
+
+#define REG_PCI_CONTROL			0x88
+#define   REG_PCI_CONTROL_PERSTOUT	BIT(29)
+#define   REG_PCI_CONTROL_PERSTOUT1	BIT(26)
+#define   REG_PCI_CONTROL_REFCLK_EN1	BIT(22)
+#define REG_GSW_CLK_DIV_SEL		0x1b4
+#define REG_EMI_CLK_DIV_SEL		0x1b8
+#define REG_BUS_CLK_DIV_SEL		0x1bc
+#define REG_SPI_CLK_DIV_SEL		0x1c4
+#define REG_SPI_CLK_FREQ_SEL		0x1c8
+#define REG_NPU_CLK_DIV_SEL		0x1fc
+#define REG_CRYPTO_CLKSRC		0x200
+#define REG_RESET_CONTROL		0x834
+#define   REG_RESET_CONTROL_PCIEHB	BIT(29)
+#define   REG_RESET_CONTROL_PCIE1	BIT(27)
+#define   REG_RESET_CONTROL_PCIE2	BIT(26)
+
+struct en_clk_desc {
+	int id;
+	const char *name;
+	u32 base_reg;
+	u8 base_bits;
+	u8 base_shift;
+	union {
+		const unsigned int *base_values;
+		unsigned int base_value;
+	};
+	size_t n_base_values;
+
+	u16 div_reg;
+	u8 div_bits;
+	u8 div_shift;
+	u16 div_val0;
+	u8 div_step;
+};
+
+struct en_clk_gate {
+	void __iomem *base;
+	struct clk_hw hw;
+};
+
+static const u32 gsw_base[] = { 400000000, 500000000 };
+static const u32 emi_base[] = { 333000000, 400000000 };
+static const u32 bus_base[] = { 500000000, 540000000 };
+static const u32 slic_base[] = { 100000000, 3125000 };
+static const u32 npu_base[] = { 333000000, 400000000, 500000000 };
+
+static const struct en_clk_desc en7523_base_clks[] = {
+	{
+		.id = EN7523_CLK_GSW,
+		.name = "gsw",
+
+		.base_reg = REG_GSW_CLK_DIV_SEL,
+		.base_bits = 1,
+		.base_shift = 8,
+		.base_values = gsw_base,
+		.n_base_values = ARRAY_SIZE(gsw_base),
+
+		.div_bits = 3,
+		.div_shift = 0,
+		.div_step = 1,
+	}, {
+		.id = EN7523_CLK_EMI,
+		.name = "emi",
+
+		.base_reg = REG_EMI_CLK_DIV_SEL,
+		.base_bits = 1,
+		.base_shift = 8,
+		.base_values = emi_base,
+		.n_base_values = ARRAY_SIZE(emi_base),
+
+		.div_bits = 3,
+		.div_shift = 0,
+		.div_step = 1,
+	}, {
+		.id = EN7523_CLK_BUS,
+		.name = "bus",
+
+		.base_reg = REG_BUS_CLK_DIV_SEL,
+		.base_bits = 1,
+		.base_shift = 8,
+		.base_values = bus_base,
+		.n_base_values = ARRAY_SIZE(bus_base),
+
+		.div_bits = 3,
+		.div_shift = 0,
+		.div_step = 1,
+	}, {
+		.id = EN7523_CLK_SLIC,
+		.name = "slic",
+
+		.base_reg = REG_SPI_CLK_FREQ_SEL,
+		.base_bits = 1,
+		.base_shift = 0,
+		.base_values = slic_base,
+		.n_base_values = ARRAY_SIZE(slic_base),
+
+		.div_reg = REG_SPI_CLK_DIV_SEL,
+		.div_bits = 5,
+		.div_shift = 24,
+		.div_val0 = 20,
+		.div_step = 2,
+	}, {
+		.id = EN7523_CLK_SPI,
+		.name = "spi",
+
+		.base_reg = REG_SPI_CLK_DIV_SEL,
+
+		.base_value = 400000000,
+
+		.div_bits = 5,
+		.div_shift = 8,
+		.div_val0 = 40,
+		.div_step = 2,
+	}, {
+		.id = EN7523_CLK_NPU,
+		.name = "npu",
+
+		.base_reg = REG_NPU_CLK_DIV_SEL,
+		.base_bits = 2,
+		.base_shift = 8,
+		.base_values = npu_base,
+		.n_base_values = ARRAY_SIZE(npu_base),
+
+		.div_bits = 3,
+		.div_shift = 0,
+		.div_step = 1,
+	}, {
+		.id = EN7523_CLK_CRYPTO,
+		.name = "crypto",
+
+		.base_reg = REG_CRYPTO_CLKSRC,
+		.base_bits = 1,
+		.base_shift = 8,
+		.base_values = emi_base,
+		.n_base_values = ARRAY_SIZE(emi_base),
+	}
+};
+
+static const struct of_device_id of_match_clk_en7523[] = {
+	{ .compatible = "airoha,en7523-scu", },
+	{ /* sentinel */ }
+};
+
+static unsigned int en7523_get_base_rate(void __iomem *base, unsigned int i)
+{
+	const struct en_clk_desc *desc = &en7523_base_clks[i];
+	u32 val;
+
+	if (!desc->base_bits)
+		return desc->base_value;
+
+	val = readl(base + desc->base_reg);
+	val >>= desc->base_shift;
+	val &= (1 << desc->base_bits) - 1;
+
+	if (val >= desc->n_base_values)
+		return 0;
+
+	return desc->base_values[val];
+}
+
+static u32 en7523_get_div(void __iomem *base, int i)
+{
+	const struct en_clk_desc *desc = &en7523_base_clks[i];
+	u32 reg, val;
+
+	if (!desc->div_bits)
+		return 1;
+
+	reg = desc->div_reg ? desc->div_reg : desc->base_reg;
+	val = readl(base + reg);
+	val >>= desc->div_shift;
+	val &= (1 << desc->div_bits) - 1;
+
+	if (!val && desc->div_val0)
+		return desc->div_val0;
+
+	return (val + 1) * desc->div_step;
+}
+
+static int en7523_pci_is_enabled(struct clk_hw *hw)
+{
+	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
+
+	return !!(readl(cg->base + REG_PCI_CONTROL) & REG_PCI_CONTROL_REFCLK_EN1);
+}
+
+static int en7523_pci_prepare(struct clk_hw *hw)
+{
+	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
+	void __iomem *np_base = cg->base;
+	u32 val, mask;
+
+	/* Need to pull device low before reset */
+	val = readl(np_base + REG_PCI_CONTROL);
+	val &= ~(REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT);
+	writel(val, np_base + REG_PCI_CONTROL);
+	usleep_range(1000, 2000);
+
+	/* Enable PCIe port 1 */
+	val |= REG_PCI_CONTROL_REFCLK_EN1;
+	writel(val, np_base + REG_PCI_CONTROL);
+	usleep_range(1000, 2000);
+
+	/* Reset to default */
+	val = readl(np_base + REG_RESET_CONTROL);
+	mask = REG_RESET_CONTROL_PCIE1 | REG_RESET_CONTROL_PCIE2 |
+	       REG_RESET_CONTROL_PCIEHB;
+	writel(val & ~mask, np_base + REG_RESET_CONTROL);
+	usleep_range(1000, 2000);
+	writel(val | mask, np_base + REG_RESET_CONTROL);
+	msleep(100);
+	writel(val & ~mask, np_base + REG_RESET_CONTROL);
+	usleep_range(5000, 10000);
+
+	/* Release device */
+	mask = REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT;
+	val = readl(np_base + REG_PCI_CONTROL);
+	writel(val & ~mask, np_base + REG_PCI_CONTROL);
+	usleep_range(1000, 2000);
+	writel(val | mask, np_base + REG_PCI_CONTROL);
+	msleep(250);
+
+	return 0;
+}
+
+static void en7523_pci_unprepare(struct clk_hw *hw)
+{
+	struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
+	void __iomem *np_base = cg->base;
+	u32 val;
+
+	val = readl(np_base + REG_PCI_CONTROL);
+	val &= ~REG_PCI_CONTROL_REFCLK_EN1;
+	writel(val, np_base + REG_PCI_CONTROL);
+}
+
+static struct clk_hw *en7523_register_pcie_clk(struct device *dev,
+					       void __iomem *np_base)
+{
+	static const struct clk_ops pcie_gate_ops = {
+		.is_enabled = en7523_pci_is_enabled,
+		.prepare = en7523_pci_prepare,
+		.unprepare = en7523_pci_unprepare,
+	};
+	struct clk_init_data init = {
+		.name = "pcie",
+		.ops = &pcie_gate_ops,
+	};
+	struct en_clk_gate *cg;
+
+	cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
+	if (!cg)
+		return NULL;
+
+	cg->base = np_base;
+	cg->hw.init = &init;
+	en7523_pci_unprepare(&cg->hw);
+
+	if (clk_hw_register(dev, &cg->hw))
+		return NULL;
+
+	return &cg->hw;
+}
+
+static void en7523_register_clocks(struct device *dev, struct clk_hw_onecell_data *clk_data,
+				   void __iomem *base, void __iomem *np_base)
+{
+	struct clk_hw *hw;
+	u32 rate;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(en7523_base_clks); i++) {
+		const struct en_clk_desc *desc = &en7523_base_clks[i];
+
+		rate = en7523_get_base_rate(base, i);
+		rate /= en7523_get_div(base, i);
+
+		hw = clk_hw_register_fixed_rate(dev, desc->name, NULL, 0, rate);
+		if (IS_ERR(hw)) {
+			pr_err("Failed to register clk %s: %ld\n",
+			       desc->name, PTR_ERR(hw));
+			continue;
+		}
+
+		clk_data->hws[desc->id] = hw;
+	}
+
+	hw = en7523_register_pcie_clk(dev, np_base);
+	clk_data->hws[EN7523_CLK_PCIE] = hw;
+
+	clk_data->num = EN7523_NUM_CLOCKS;
+}
+
+static int en7523_clk_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct clk_hw_onecell_data *clk_data;
+	void __iomem *base, *np_base;
+	int r;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	np_base = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(np_base))
+		return PTR_ERR(np_base);
+
+	clk_data = devm_kzalloc(&pdev->dev,
+				struct_size(clk_data, hws, EN7523_NUM_CLOCKS),
+				GFP_KERNEL);
+	if (!clk_data)
+		return -ENOMEM;
+
+	en7523_register_clocks(&pdev->dev, clk_data, base, np_base);
+
+	r = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
+	if (r)
+		dev_err(&pdev->dev,
+			"could not register clock provider: %s: %d\n",
+			pdev->name, r);
+
+	return r;
+}
+
+static struct platform_driver clk_en7523_drv = {
+	.probe = en7523_clk_probe,
+	.driver = {
+		.name = "clk-en7523",
+		.of_match_table = of_match_clk_en7523,
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init clk_en7523_init(void)
+{
+	return platform_driver_register(&clk_en7523_drv);
+}
+
+arch_initcall(clk_en7523_init);
diff --git a/target/linux/airoha/files/drivers/gpio/gpio-en7523.c b/target/linux/airoha/files/drivers/gpio/gpio-en7523.c
new file mode 100644
index 0000000000..f836a8db4c
--- /dev/null
+++ b/target/linux/airoha/files/drivers/gpio/gpio-en7523.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/types.h>
+#include <linux/io.h>
+#include <linux/bits.h>
+#include <linux/gpio/driver.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+
+#define AIROHA_GPIO_MAX		32
+
+/**
+ * airoha_gpio_ctrl - Airoha GPIO driver data
+ * @gc: Associated gpio_chip instance.
+ * @data: The data register.
+ * @dir0: The direction register for the lower 16 pins.
+ * @dir1: The direction register for the higher 16 pins.
+ * @output: The output enable register.
+ */
+struct airoha_gpio_ctrl {
+	struct gpio_chip gc;
+	void __iomem *data;
+	void __iomem *dir[2];
+	void __iomem *output;
+};
+
+static struct airoha_gpio_ctrl *gc_to_ctrl(struct gpio_chip *gc)
+{
+	return container_of(gc, struct airoha_gpio_ctrl, gc);
+}
+
+static int airoha_dir_set(struct gpio_chip *gc, unsigned int gpio,
+			  int val, int out)
+{
+	struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
+	u32 dir = ioread32(ctrl->dir[gpio / 16]);
+	u32 output = ioread32(ctrl->output);
+	u32 mask = BIT((gpio % 16) * 2);
+
+	if (out) {
+		dir |= mask;
+		output |= BIT(gpio);
+	} else {
+		dir &= ~mask;
+		output &= ~BIT(gpio);
+	}
+
+	iowrite32(dir, ctrl->dir[gpio / 16]);
+
+	if (out)
+		gc->set(gc, gpio, val);
+
+	iowrite32(output, ctrl->output);
+
+	return 0;
+}
+
+static int airoha_dir_out(struct gpio_chip *gc, unsigned int gpio,
+			  int val)
+{
+	return airoha_dir_set(gc, gpio, val, 1);
+}
+
+static int airoha_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+	return airoha_dir_set(gc, gpio, 0, 0);
+}
+
+static int airoha_get_dir(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
+	u32 dir = ioread32(ctrl->dir[gpio / 16]);
+	u32 mask = BIT((gpio % 16) * 2);
+
+	return (dir & mask) ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
+}
+
+static int airoha_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct airoha_gpio_ctrl *ctrl;
+	int err;
+
+	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	ctrl->data = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ctrl->data))
+		return PTR_ERR(ctrl->data);
+
+	ctrl->dir[0] = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(ctrl->dir[0]))
+		return PTR_ERR(ctrl->dir[0]);
+
+	ctrl->dir[1] = devm_platform_ioremap_resource(pdev, 2);
+	if (IS_ERR(ctrl->dir[1]))
+		return PTR_ERR(ctrl->dir[1]);
+
+	ctrl->output = devm_platform_ioremap_resource(pdev, 3);
+	if (IS_ERR(ctrl->output))
+		return PTR_ERR(ctrl->output);
+
+	err = bgpio_init(&ctrl->gc, dev, 4, ctrl->data, NULL,
+			 NULL, NULL, NULL, 0);
+	if (err)
+		return dev_err_probe(dev, err, "unable to init generic GPIO");
+
+	ctrl->gc.ngpio = AIROHA_GPIO_MAX;
+	ctrl->gc.owner = THIS_MODULE;
+	ctrl->gc.direction_output = airoha_dir_out;
+	ctrl->gc.direction_input = airoha_dir_in;
+	ctrl->gc.get_direction = airoha_get_dir;
+
+	return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
+}
+
+static const struct of_device_id airoha_gpio_of_match[] = {
+	{ .compatible = "airoha,en7523-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, airoha_gpio_of_match);
+
+static struct platform_driver airoha_gpio_driver = {
+	.driver = {
+		.name = "airoha-gpio",
+		.of_match_table	= airoha_gpio_of_match,
+	},
+	.probe = airoha_gpio_probe,
+};
+module_platform_driver(airoha_gpio_driver);
+
+MODULE_DESCRIPTION("Airoha GPIO support");
+MODULE_AUTHOR("John Crispin <john@phrozen.org>");
+MODULE_LICENSE("GPL v2");
diff --git a/target/linux/airoha/files/include/dt-bindings/clock/en7523-clk.h b/target/linux/airoha/files/include/dt-bindings/clock/en7523-clk.h
new file mode 100644
index 0000000000..717d23a5e5
--- /dev/null
+++ b/target/linux/airoha/files/include/dt-bindings/clock/en7523-clk.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+
+#ifndef _DT_BINDINGS_CLOCK_AIROHA_EN7523_H_
+#define _DT_BINDINGS_CLOCK_AIROHA_EN7523_H_
+
+#define EN7523_CLK_GSW		0
+#define EN7523_CLK_EMI		1
+#define EN7523_CLK_BUS		2
+#define EN7523_CLK_SLIC		3
+#define EN7523_CLK_SPI		4
+#define EN7523_CLK_NPU		5
+#define EN7523_CLK_CRYPTO	6
+#define EN7523_CLK_PCIE		7
+
+#define EN7523_NUM_CLOCKS	8
+
+#endif /* _DT_BINDINGS_CLOCK_AIROHA_EN7523_H_ */