/*
 * Marvell Armada CP110 System Controller
 *
 * Copyright (C) 2016 Marvell
 *
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

/*
 * CP110 has 6 core clocks:
 *
 *  - APLL		(1 Ghz)
 *    - PPv2 core	(1/3 APLL)
 *    - EIP		(1/2 APLL)
 *     - Core		(1/2 EIP)
 *    - SDIO		(2/5 APLL)
 *
 *  - NAND clock, which is either:
 *    - Equal to SDIO clock
 *    - 2/5 APLL
 *
 * CP110 has 32 gatable clocks, for the various peripherals in the
 * IP. They have fairly complicated parent/child relationships.
 */

#define pr_fmt(fmt) "cp110-system-controller: " fmt

#include <linux/clk-provider.h>
#include <linux/mfd/syscon.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#define CP110_PM_CLOCK_GATING_REG	0x220
#define CP110_NAND_FLASH_CLK_CTRL_REG	0x700
#define    NF_CLOCK_SEL_400_MASK	BIT(0)

enum {
	CP110_CLK_TYPE_CORE,
	CP110_CLK_TYPE_GATABLE,
};

#define CP110_MAX_CORE_CLOCKS		6
#define CP110_MAX_GATABLE_CLOCKS	32

#define CP110_CLK_NUM \
	(CP110_MAX_CORE_CLOCKS + CP110_MAX_GATABLE_CLOCKS)

#define CP110_CORE_APLL			0
#define CP110_CORE_PPV2			1
#define CP110_CORE_EIP			2
#define CP110_CORE_CORE			3
#define CP110_CORE_NAND			4
#define CP110_CORE_SDIO			5

/* A number of gatable clocks need special handling */
#define CP110_GATE_AUDIO		0
#define CP110_GATE_COMM_UNIT		1
#define CP110_GATE_NAND			2
#define CP110_GATE_PPV2			3
#define CP110_GATE_SDIO			4
#define CP110_GATE_MG			5
#define CP110_GATE_MG_CORE		6
#define CP110_GATE_XOR1			7
#define CP110_GATE_XOR0			8
#define CP110_GATE_GOP_DP		9
#define CP110_GATE_PCIE_X1_0		11
#define CP110_GATE_PCIE_X1_1		12
#define CP110_GATE_PCIE_X4		13
#define CP110_GATE_PCIE_XOR		14
#define CP110_GATE_SATA			15
#define CP110_GATE_SATA_USB		16
#define CP110_GATE_MAIN			17
#define CP110_GATE_SDMMC_GOP		18
#define CP110_GATE_SLOW_IO		21
#define CP110_GATE_USB3H0		22
#define CP110_GATE_USB3H1		23
#define CP110_GATE_USB3DEV		24
#define CP110_GATE_EIP150		25
#define CP110_GATE_EIP197		26

static const char * const gate_base_names[] = {
	[CP110_GATE_AUDIO]	= "audio",
	[CP110_GATE_COMM_UNIT]	= "communit",
	[CP110_GATE_NAND]	= "nand",
	[CP110_GATE_PPV2]	= "ppv2",
	[CP110_GATE_SDIO]	= "sdio",
	[CP110_GATE_MG]		= "mg-domain",
	[CP110_GATE_MG_CORE]	= "mg-core",
	[CP110_GATE_XOR1]	= "xor1",
	[CP110_GATE_XOR0]	= "xor0",
	[CP110_GATE_GOP_DP]	= "gop-dp",
	[CP110_GATE_PCIE_X1_0]	= "pcie_x10",
	[CP110_GATE_PCIE_X1_1]	= "pcie_x11",
	[CP110_GATE_PCIE_X4]	= "pcie_x4",
	[CP110_GATE_PCIE_XOR]	= "pcie-xor",
	[CP110_GATE_SATA]	= "sata",
	[CP110_GATE_SATA_USB]	= "sata-usb",
	[CP110_GATE_MAIN]	= "main",
	[CP110_GATE_SDMMC_GOP]	= "sd-mmc-gop",
	[CP110_GATE_SLOW_IO]	= "slow-io",
	[CP110_GATE_USB3H0]	= "usb3h0",
	[CP110_GATE_USB3H1]	= "usb3h1",
	[CP110_GATE_USB3DEV]	= "usb3dev",
	[CP110_GATE_EIP150]	= "eip150",
	[CP110_GATE_EIP197]	= "eip197"
};

struct cp110_gate_clk {
	struct clk_hw hw;
	struct regmap *regmap;
	u8 bit_idx;
};

#define to_cp110_gate_clk(hw) container_of(hw, struct cp110_gate_clk, hw)

static int cp110_gate_enable(struct clk_hw *hw)
{
	struct cp110_gate_clk *gate = to_cp110_gate_clk(hw);

	regmap_update_bits(gate->regmap, CP110_PM_CLOCK_GATING_REG,
			   BIT(gate->bit_idx), BIT(gate->bit_idx));

	return 0;
}

static void cp110_gate_disable(struct clk_hw *hw)
{
	struct cp110_gate_clk *gate = to_cp110_gate_clk(hw);

	regmap_update_bits(gate->regmap, CP110_PM_CLOCK_GATING_REG,
			   BIT(gate->bit_idx), 0);
}

static int cp110_gate_is_enabled(struct clk_hw *hw)
{
	struct cp110_gate_clk *gate = to_cp110_gate_clk(hw);
	u32 val;

	regmap_read(gate->regmap, CP110_PM_CLOCK_GATING_REG, &val);

	return val & BIT(gate->bit_idx);
}

static const struct clk_ops cp110_gate_ops = {
	.enable = cp110_gate_enable,
	.disable = cp110_gate_disable,
	.is_enabled = cp110_gate_is_enabled,
};

static struct clk_hw *cp110_register_gate(const char *name,
					  const char *parent_name,
					  struct regmap *regmap, u8 bit_idx)
{
	struct cp110_gate_clk *gate;
	struct clk_hw *hw;
	struct clk_init_data init;
	int ret;

	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
	if (!gate)
		return ERR_PTR(-ENOMEM);

	memset(&init, 0, sizeof(init));

	init.name = name;
	init.ops = &cp110_gate_ops;
	init.parent_names = &parent_name;
	init.num_parents = 1;

	gate->regmap = regmap;
	gate->bit_idx = bit_idx;
	gate->hw.init = &init;

	hw = &gate->hw;
	ret = clk_hw_register(NULL, hw);
	if (ret) {
		kfree(gate);
		hw = ERR_PTR(ret);
	}

	return hw;
}

static void cp110_unregister_gate(struct clk_hw *hw)
{
	clk_hw_unregister(hw);
	kfree(to_cp110_gate_clk(hw));
}

static struct clk_hw *cp110_of_clk_get(struct of_phandle_args *clkspec,
				       void *data)
{
	struct clk_hw_onecell_data *clk_data = data;
	unsigned int type = clkspec->args[0];
	unsigned int idx = clkspec->args[1];

	if (type == CP110_CLK_TYPE_CORE) {
		if (idx >= CP110_MAX_CORE_CLOCKS)
			return ERR_PTR(-EINVAL);
		return clk_data->hws[idx];
	} else if (type == CP110_CLK_TYPE_GATABLE) {
		if (idx >= CP110_MAX_GATABLE_CLOCKS)
			return ERR_PTR(-EINVAL);
		return clk_data->hws[CP110_MAX_CORE_CLOCKS + idx];
	}

	return ERR_PTR(-EINVAL);
}

static char *cp110_unique_name(struct device *dev, struct device_node *np,
			       const char *name)
{
	const __be32 *reg;
	u64 addr;

	/* Do not create a name if there is no clock */
	if (!name)
		return NULL;

	reg = of_get_property(np, "reg", NULL);
	addr = of_translate_address(np, reg);
	return devm_kasprintf(dev, GFP_KERNEL, "%llx-%s",
			      (unsigned long long)addr, name);
}

static int cp110_syscon_common_probe(struct platform_device *pdev,
				     struct device_node *syscon_node)
{
	struct regmap *regmap;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	const char *ppv2_name, *apll_name, *core_name, *eip_name, *nand_name,
		*sdio_name;
	struct clk_hw_onecell_data *cp110_clk_data;
	struct clk_hw *hw, **cp110_clks;
	u32 nand_clk_ctrl;
	int i, ret;
	char *gate_name[ARRAY_SIZE(gate_base_names)];

	regmap = syscon_node_to_regmap(syscon_node);
	if (IS_ERR(regmap))
		return PTR_ERR(regmap);

	ret = regmap_read(regmap, CP110_NAND_FLASH_CLK_CTRL_REG,
			  &nand_clk_ctrl);
	if (ret)
		return ret;

	cp110_clk_data = devm_kzalloc(dev, sizeof(*cp110_clk_data) +
				      sizeof(struct clk_hw *) * CP110_CLK_NUM,
				      GFP_KERNEL);
	if (!cp110_clk_data)
		return -ENOMEM;

	cp110_clks = cp110_clk_data->hws;
	cp110_clk_data->num = CP110_CLK_NUM;

	/* Register the APLL which is the root of the hw tree */
	apll_name = cp110_unique_name(dev, syscon_node, "apll");
	hw = clk_hw_register_fixed_rate(NULL, apll_name, NULL, 0,
					1000 * 1000 * 1000);
	if (IS_ERR(hw)) {
		ret = PTR_ERR(hw);
		goto fail_apll;
	}

	cp110_clks[CP110_CORE_APLL] = hw;

	/* PPv2 is APLL/3 */
	ppv2_name = cp110_unique_name(dev, syscon_node, "ppv2-core");
	hw = clk_hw_register_fixed_factor(NULL, ppv2_name, apll_name, 0, 1, 3);
	if (IS_ERR(hw)) {
		ret = PTR_ERR(hw);
		goto fail_ppv2;
	}

	cp110_clks[CP110_CORE_PPV2] = hw;

	/* EIP clock is APLL/2 */
	eip_name = cp110_unique_name(dev, syscon_node, "eip");
	hw = clk_hw_register_fixed_factor(NULL, eip_name, apll_name, 0, 1, 2);
	if (IS_ERR(hw)) {
		ret = PTR_ERR(hw);
		goto fail_eip;
	}

	cp110_clks[CP110_CORE_EIP] = hw;

	/* Core clock is EIP/2 */
	core_name = cp110_unique_name(dev, syscon_node, "core");
	hw = clk_hw_register_fixed_factor(NULL, core_name, eip_name, 0, 1, 2);
	if (IS_ERR(hw)) {
		ret = PTR_ERR(hw);
		goto fail_core;
	}

	cp110_clks[CP110_CORE_CORE] = hw;
	/* NAND can be either APLL/2.5 or core clock */
	nand_name = cp110_unique_name(dev, syscon_node, "nand-core");
	if (nand_clk_ctrl & NF_CLOCK_SEL_400_MASK)
		hw = clk_hw_register_fixed_factor(NULL, nand_name,
						   apll_name, 0, 2, 5);
	else
		hw = clk_hw_register_fixed_factor(NULL, nand_name,
						   core_name, 0, 1, 1);
	if (IS_ERR(hw)) {
		ret = PTR_ERR(hw);
		goto fail_nand;
	}

	cp110_clks[CP110_CORE_NAND] = hw;

	/* SDIO clock is APLL/2.5 */
	sdio_name = cp110_unique_name(dev, syscon_node, "sdio-core");
	hw = clk_hw_register_fixed_factor(NULL, sdio_name,
					  apll_name, 0, 2, 5);
	if (IS_ERR(hw)) {
		ret = PTR_ERR(hw);
		goto fail_sdio;
	}

	cp110_clks[CP110_CORE_SDIO] = hw;

	/* create the unique name for all the gate clocks */
	for (i = 0; i < ARRAY_SIZE(gate_base_names); i++)
		gate_name[i] =	cp110_unique_name(dev, syscon_node,
						  gate_base_names[i]);

	for (i = 0; i < ARRAY_SIZE(gate_base_names); i++) {
		const char *parent;

		if (gate_name[i] == NULL)
			continue;

		switch (i) {
		case CP110_GATE_AUDIO:
		case CP110_GATE_COMM_UNIT:
		case CP110_GATE_EIP150:
		case CP110_GATE_EIP197:
		case CP110_GATE_SLOW_IO:
			parent = gate_name[CP110_GATE_MAIN];
			break;
		case CP110_GATE_MG:
			parent = gate_name[CP110_GATE_MG_CORE];
			break;
		case CP110_GATE_NAND:
			parent = nand_name;
			break;
		case CP110_GATE_PPV2:
			parent = ppv2_name;
			break;
		case CP110_GATE_SDIO:
			parent = sdio_name;
			break;
		case CP110_GATE_GOP_DP:
			parent = gate_name[CP110_GATE_SDMMC_GOP];
			break;
		case CP110_GATE_XOR1:
		case CP110_GATE_XOR0:
		case CP110_GATE_PCIE_X1_0:
		case CP110_GATE_PCIE_X1_1:
		case CP110_GATE_PCIE_X4:
			parent = gate_name[CP110_GATE_PCIE_XOR];
			break;
		case CP110_GATE_SATA:
		case CP110_GATE_USB3H0:
		case CP110_GATE_USB3H1:
		case CP110_GATE_USB3DEV:
			parent = gate_name[CP110_GATE_SATA_USB];
			break;
		default:
			parent = core_name;
			break;
		}
		hw = cp110_register_gate(gate_name[i], parent, regmap, i);

		if (IS_ERR(hw)) {
			ret = PTR_ERR(hw);
			goto fail_gate;
		}

		cp110_clks[CP110_MAX_CORE_CLOCKS + i] = hw;
	}

	ret = of_clk_add_hw_provider(np, cp110_of_clk_get, cp110_clk_data);
	if (ret)
		goto fail_clk_add;

	platform_set_drvdata(pdev, cp110_clks);

	return 0;

fail_clk_add:
fail_gate:
	for (i = 0; i < CP110_MAX_GATABLE_CLOCKS; i++) {
		hw = cp110_clks[CP110_MAX_CORE_CLOCKS + i];

		if (hw)
			cp110_unregister_gate(hw);
	}

	clk_hw_unregister_fixed_factor(cp110_clks[CP110_CORE_SDIO]);
fail_sdio:
	clk_hw_unregister_fixed_factor(cp110_clks[CP110_CORE_NAND]);
fail_nand:
	clk_hw_unregister_fixed_factor(cp110_clks[CP110_CORE_CORE]);
fail_core:
	clk_hw_unregister_fixed_factor(cp110_clks[CP110_CORE_EIP]);
fail_eip:
	clk_hw_unregister_fixed_factor(cp110_clks[CP110_CORE_PPV2]);
fail_ppv2:
	clk_hw_unregister_fixed_rate(cp110_clks[CP110_CORE_APLL]);
fail_apll:
	return ret;
}

static int cp110_syscon_legacy_clk_probe(struct platform_device *pdev)
{
	dev_warn(&pdev->dev, FW_WARN "Using legacy device tree binding\n");
	dev_warn(&pdev->dev, FW_WARN "Update your device tree:\n");
	dev_warn(&pdev->dev, FW_WARN
		 "This binding won't be supported in future kernels\n");

	return cp110_syscon_common_probe(pdev, pdev->dev.of_node);
}

static int cp110_clk_probe(struct platform_device *pdev)
{
	return cp110_syscon_common_probe(pdev, pdev->dev.of_node->parent);
}

static const struct of_device_id cp110_syscon_legacy_of_match[] = {
	{ .compatible = "marvell,cp110-system-controller0", },
	{ }
};

static struct platform_driver cp110_syscon_legacy_driver = {
	.probe = cp110_syscon_legacy_clk_probe,
	.driver		= {
		.name	= "marvell-cp110-system-controller0",
		.of_match_table = cp110_syscon_legacy_of_match,
		.suppress_bind_attrs = true,
	},
};
builtin_platform_driver(cp110_syscon_legacy_driver);

static const struct of_device_id cp110_clock_of_match[] = {
	{ .compatible = "marvell,cp110-clock", },
	{ }
};

static struct platform_driver cp110_clock_driver = {
	.probe = cp110_clk_probe,
	.driver		= {
		.name	= "marvell-cp110-clock",
		.of_match_table = cp110_clock_of_match,
		.suppress_bind_attrs = true,
	},
};
builtin_platform_driver(cp110_clock_driver);