drivers/clk/clk-gemini.c - linux/kernel/git/bpf/bpf - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Cortina Gemini SoC Clock Controller driver
  * Copyright (c) 2017 Linus Walleij <linus.walleij@linaro.org>
  */

 #define pr_fmt(fmt) "clk-gemini: " fmt

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/clk-provider.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 #include <linux/spinlock.h>
 #include <linux/reset-controller.h>
 #include <dt-bindings/reset/cortina,gemini-reset.h>
 #include <dt-bindings/clock/cortina,gemini-clock.h>

 /* Globally visible clocks */
 static DEFINE_SPINLOCK(gemini_clk_lock);

 #define GEMINI_GLOBAL_STATUS		0x04
 #define PLL_OSC_SEL			BIT(30)
 #define AHBSPEED_SHIFT			(15)
 #define AHBSPEED_MASK			0x07
 #define CPU_AHB_RATIO_SHIFT		(18)
 #define CPU_AHB_RATIO_MASK		0x03

 #define GEMINI_GLOBAL_PLL_CONTROL	0x08

 #define GEMINI_GLOBAL_SOFT_RESET	0x0c

 #define GEMINI_GLOBAL_MISC_CONTROL	0x30
 #define PCI_CLK_66MHZ			BIT(18)

 #define GEMINI_GLOBAL_CLOCK_CONTROL	0x34
 #define PCI_CLKRUN_EN			BIT(16)
 #define TVC_HALFDIV_SHIFT		(24)
 #define TVC_HALFDIV_MASK		0x1f
 #define SECURITY_CLK_SEL		BIT(29)

 #define GEMINI_GLOBAL_PCI_DLL_CONTROL	0x44
 #define PCI_DLL_BYPASS			BIT(31)
 #define PCI_DLL_TAP_SEL_MASK		0x1f

 /**
  * struct gemini_data_data - Gemini gated clocks
  * @bit_idx: the bit used to gate this clock in the clock register
  * @name: the clock name
  * @parent_name: the name of the parent clock
  * @flags: standard clock framework flags
  */
 struct gemini_gate_data {
 	u8 bit_idx;
 	const char *name;
 	const char *parent_name;
 	unsigned long flags;
 };

 /**
  * struct clk_gemini_pci - Gemini PCI clock
  * @hw: corresponding clock hardware entry
  * @map: regmap to access the registers
  * @rate: current rate
  */
 struct clk_gemini_pci {
 	struct clk_hw hw;
 	struct regmap *map;
 	unsigned long rate;
 };

 /**
  * struct gemini_reset - gemini reset controller
  * @map: regmap to access the containing system controller
  * @rcdev: reset controller device
  */
 struct gemini_reset {
 	struct regmap *map;
 	struct reset_controller_dev rcdev;
 };

 /* Keeps track of all clocks */
 static struct clk_hw_onecell_data *gemini_clk_data;

 static const struct gemini_gate_data gemini_gates[] = {
 	{ 1, "security-gate", "secdiv", 0 },
 	{ 2, "gmac0-gate", "ahb", 0 },
 	{ 3, "gmac1-gate", "ahb", 0 },
 	{ 4, "sata0-gate", "ahb", 0 },
 	{ 5, "sata1-gate", "ahb", 0 },
 	{ 6, "usb0-gate", "ahb", 0 },
 	{ 7, "usb1-gate", "ahb", 0 },
 	{ 8, "ide-gate", "ahb", 0 },
 	{ 9, "pci-gate", "ahb", 0 },
 	/*
 	 * The DDR controller may never have a driver, but certainly must
 	 * not be gated off.
 	 */
 	{ 10, "ddr-gate", "ahb", CLK_IS_CRITICAL },
 	/*
 	 * The flash controller must be on to access NOR flash through the
 	 * memory map.
 	 */
 	{ 11, "flash-gate", "ahb", CLK_IGNORE_UNUSED },
 	{ 12, "tvc-gate", "ahb", 0 },
 	{ 13, "boot-gate", "apb", 0 },
 };

 #define to_pciclk(_hw) container_of(_hw, struct clk_gemini_pci, hw)

 #define to_gemini_reset(p) container_of((p), struct gemini_reset, rcdev)

 static unsigned long gemini_pci_recalc_rate(struct clk_hw *hw,
 					    unsigned long parent_rate)
 {
 	struct clk_gemini_pci *pciclk = to_pciclk(hw);
 	u32 val;

 	regmap_read(pciclk->map, GEMINI_GLOBAL_MISC_CONTROL, &val);
 	if (val & PCI_CLK_66MHZ)
 		return 66000000;
 	return 33000000;
 }

 static long gemini_pci_round_rate(struct clk_hw *hw, unsigned long rate,
 				  unsigned long *prate)
 {
 	/* We support 33 and 66 MHz */
 	if (rate < 48000000)
 		return 33000000;
 	return 66000000;
 }

 static int gemini_pci_set_rate(struct clk_hw *hw, unsigned long rate,
 			       unsigned long parent_rate)
 {
 	struct clk_gemini_pci *pciclk = to_pciclk(hw);

 	if (rate == 33000000)
 		return regmap_update_bits(pciclk->map,
 					  GEMINI_GLOBAL_MISC_CONTROL,
 					  PCI_CLK_66MHZ, 0);
 	if (rate == 66000000)
 		return regmap_update_bits(pciclk->map,
 					  GEMINI_GLOBAL_MISC_CONTROL,
 					  0, PCI_CLK_66MHZ);
 	return -EINVAL;
 }

 static int gemini_pci_enable(struct clk_hw *hw)
 {
 	struct clk_gemini_pci *pciclk = to_pciclk(hw);

 	regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
 			   0, PCI_CLKRUN_EN);
 	return 0;
 }

 static void gemini_pci_disable(struct clk_hw *hw)
 {
 	struct clk_gemini_pci *pciclk = to_pciclk(hw);

 	regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
 			   PCI_CLKRUN_EN, 0);
 }

 static int gemini_pci_is_enabled(struct clk_hw *hw)
 {
 	struct clk_gemini_pci *pciclk = to_pciclk(hw);
 	unsigned int val;

 	regmap_read(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
 	return !!(val & PCI_CLKRUN_EN);
 }

 static const struct clk_ops gemini_pci_clk_ops = {
 	.recalc_rate = gemini_pci_recalc_rate,
 	.round_rate = gemini_pci_round_rate,
 	.set_rate = gemini_pci_set_rate,
 	.enable = gemini_pci_enable,
 	.disable = gemini_pci_disable,
 	.is_enabled = gemini_pci_is_enabled,
 };

 static struct clk_hw *gemini_pci_clk_setup(const char *name,
 					   const char *parent_name,
 					   struct regmap *map)
 {
 	struct clk_gemini_pci *pciclk;
 	struct clk_init_data init;
 	int ret;

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

 	init.name = name;
 	init.ops = &gemini_pci_clk_ops;
 	init.flags = 0;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;
 	pciclk->map = map;
 	pciclk->hw.init = &init;

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

 	return &pciclk->hw;
 }

 /*
  * This is a self-deasserting reset controller.
  */
 static int gemini_reset(struct reset_controller_dev *rcdev,
 			unsigned long id)
 {
 	struct gemini_reset *gr = to_gemini_reset(rcdev);

 	/* Manual says to always set BIT 30 (CPU1) to 1 */
 	return regmap_write(gr->map,
 			    GEMINI_GLOBAL_SOFT_RESET,
 			    BIT(GEMINI_RESET_CPU1) | BIT(id));
 }

 static int gemini_reset_assert(struct reset_controller_dev *rcdev,
 			       unsigned long id)
 {
 	return 0;
 }

 static int gemini_reset_deassert(struct reset_controller_dev *rcdev,
 				 unsigned long id)
 {
 	return 0;
 }

 static int gemini_reset_status(struct reset_controller_dev *rcdev,
 			     unsigned long id)
 {
 	struct gemini_reset *gr = to_gemini_reset(rcdev);
 	u32 val;
 	int ret;

 	ret = regmap_read(gr->map, GEMINI_GLOBAL_SOFT_RESET, &val);
 	if (ret)
 		return ret;

 	return !!(val & BIT(id));
 }

 static const struct reset_control_ops gemini_reset_ops = {
 	.reset = gemini_reset,
 	.assert = gemini_reset_assert,
 	.deassert = gemini_reset_deassert,
 	.status = gemini_reset_status,
 };

 static int gemini_clk_probe(struct platform_device *pdev)
 {
 	/* Gives the fracions 1x, 1.5x, 1.85x and 2x */
 	unsigned int cpu_ahb_mult[4] = { 1, 3, 24, 2 };
 	unsigned int cpu_ahb_div[4] = { 1, 2, 13, 1 };
 	void __iomem *base;
 	struct gemini_reset *gr;
 	struct regmap *map;
 	struct clk_hw *hw;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	unsigned int mult, div;
 	struct resource *res;
 	u32 val;
 	int ret;
 	int i;

 	gr = devm_kzalloc(dev, sizeof(*gr), GFP_KERNEL);
 	if (!gr)
 		return -ENOMEM;

 	/* Remap the system controller for the exclusive register */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(base))
 		return PTR_ERR(base);

 	map = syscon_node_to_regmap(np);
 	if (IS_ERR(map)) {
 		dev_err(dev, "no syscon regmap\n");
 		return PTR_ERR(map);
 	}

 	gr->map = map;
 	gr->rcdev.owner = THIS_MODULE;
 	gr->rcdev.nr_resets = 32;
 	gr->rcdev.ops = &gemini_reset_ops;
 	gr->rcdev.of_node = np;

 	ret = devm_reset_controller_register(dev, &gr->rcdev);
 	if (ret) {
 		dev_err(dev, "could not register reset controller\n");
 		return ret;
 	}

 	/* RTC clock 32768 Hz */
 	hw = clk_hw_register_fixed_rate(NULL, "rtc", NULL, 0, 32768);
 	gemini_clk_data->hws[GEMINI_CLK_RTC] = hw;

 	/* CPU clock derived as a fixed ratio from the AHB clock */
 	regmap_read(map, GEMINI_GLOBAL_STATUS, &val);
 	val >>= CPU_AHB_RATIO_SHIFT;
 	val &= CPU_AHB_RATIO_MASK;
 	hw = clk_hw_register_fixed_factor(NULL, "cpu", "ahb", 0,
 					  cpu_ahb_mult[val],
 					  cpu_ahb_div[val]);
 	gemini_clk_data->hws[GEMINI_CLK_CPU] = hw;

 	/* Security clock is 1:1 or 0.75 of APB */
 	regmap_read(map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
 	if (val & SECURITY_CLK_SEL) {
 		mult = 1;
 		div = 1;
 	} else {
 		mult = 3;
 		div = 4;
 	}
 	hw = clk_hw_register_fixed_factor(NULL, "secdiv", "ahb", 0, mult, div);

 	/*
 	 * These are the leaf gates, at boot no clocks are gated.
 	 */
 	for (i = 0; i < ARRAY_SIZE(gemini_gates); i++) {
 		const struct gemini_gate_data *gd;

 		gd = &gemini_gates[i];
 		gemini_clk_data->hws[GEMINI_CLK_GATES + i] =
 			clk_hw_register_gate(NULL, gd->name,
 					     gd->parent_name,
 					     gd->flags,
 					     base + GEMINI_GLOBAL_CLOCK_CONTROL,
 					     gd->bit_idx,
 					     CLK_GATE_SET_TO_DISABLE,
 					     &gemini_clk_lock);
 	}

 	/*
 	 * The TV Interface Controller has a 5-bit half divider register.
 	 * This clock is supposed to be 27MHz as this is an exact multiple
 	 * of PAL and NTSC frequencies. The register is undocumented :(
 	 * FIXME: figure out the parent and how the divider works.
 	 */
 	mult = 1;
 	div = ((val >> TVC_HALFDIV_SHIFT) & TVC_HALFDIV_MASK);
 	dev_dbg(dev, "TVC half divider value = %d\n", div);
 	div += 1;
 	hw = clk_hw_register_fixed_rate(NULL, "tvcdiv", "xtal", 0, 27000000);
 	gemini_clk_data->hws[GEMINI_CLK_TVC] = hw;

 	/* FIXME: very unclear what the parent is */
 	hw = gemini_pci_clk_setup("PCI", "xtal", map);
 	gemini_clk_data->hws[GEMINI_CLK_PCI] = hw;

 	/* FIXME: very unclear what the parent is */
 	hw = clk_hw_register_fixed_rate(NULL, "uart", "xtal", 0, 48000000);
 	gemini_clk_data->hws[GEMINI_CLK_UART] = hw;

 	return 0;
 }

 static const struct of_device_id gemini_clk_dt_ids[] = {
 	{ .compatible = "cortina,gemini-syscon", },
 	{ /* sentinel */ },
 };

 static struct platform_driver gemini_clk_driver = {
 	.probe  = gemini_clk_probe,
 	.driver = {
 		.name = "gemini-clk",
 		.of_match_table = gemini_clk_dt_ids,
 		.suppress_bind_attrs = true,
 	},
 };
 builtin_platform_driver(gemini_clk_driver);

 static void __init gemini_cc_init(struct device_node *np)
 {
 	struct regmap *map;
 	struct clk_hw *hw;
 	unsigned long freq;
 	unsigned int mult, div;
 	u32 val;
 	int ret;
 	int i;

 	gemini_clk_data = kzalloc(struct_size(gemini_clk_data, hws,
 					      GEMINI_NUM_CLKS),
 				  GFP_KERNEL);
 	if (!gemini_clk_data)
 		return;

 	/*
 	 * This way all clock fetched before the platform device probes,
 	 * except those we assign here for early use, will be deferred.
 	 */
 	for (i = 0; i < GEMINI_NUM_CLKS; i++)
 		gemini_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);

 	map = syscon_node_to_regmap(np);
 	if (IS_ERR(map)) {
 		pr_err("no syscon regmap\n");
 		return;
 	}
 	/*
 	 * We check that the regmap works on this very first access,
 	 * but as this is an MMIO-backed regmap, subsequent regmap
 	 * access is not going to fail and we skip error checks from
 	 * this point.
 	 */
 	ret = regmap_read(map, GEMINI_GLOBAL_STATUS, &val);
 	if (ret) {
 		pr_err("failed to read global status register\n");
 		return;
 	}

 	/*
 	 * XTAL is the crystal oscillator, 60 or 30 MHz selected from
 	 * strap pin E6
 	 */
 	if (val & PLL_OSC_SEL)
 		freq = 30000000;
 	else
 		freq = 60000000;
 	hw = clk_hw_register_fixed_rate(NULL, "xtal", NULL, 0, freq);
 	pr_debug("main crystal @%lu MHz\n", freq / 1000000);

 	/* VCO clock derived from the crystal */
 	mult = 13 + ((val >> AHBSPEED_SHIFT) & AHBSPEED_MASK);
 	div = 2;
 	/* If we run on 30 MHz crystal we have to multiply with two */
 	if (val & PLL_OSC_SEL)
 		mult *= 2;
 	hw = clk_hw_register_fixed_factor(NULL, "vco", "xtal", 0, mult, div);

 	/* The AHB clock is always 1/3 of the VCO */
 	hw = clk_hw_register_fixed_factor(NULL, "ahb", "vco", 0, 1, 3);
 	gemini_clk_data->hws[GEMINI_CLK_AHB] = hw;

 	/* The APB clock is always 1/6 of the AHB */
 	hw = clk_hw_register_fixed_factor(NULL, "apb", "ahb", 0, 1, 6);
 	gemini_clk_data->hws[GEMINI_CLK_APB] = hw;

 	/* Register the clocks to be accessed by the device tree */
 	gemini_clk_data->num = GEMINI_NUM_CLKS;
 	of_clk_add_hw_provider(np, of_clk_hw_onecell_get, gemini_clk_data);
 }
 CLK_OF_DECLARE_DRIVER(gemini_cc, "cortina,gemini-syscon", gemini_cc_init);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Cortina Gemini SoC Clock Controller driver
	* Copyright (c) 2017 Linus Walleij <linus.walleij@linaro.org>
	*/

	#define pr_fmt(fmt) "clk-gemini: " fmt

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/clk-provider.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/mfd/syscon.h>
	#include <linux/regmap.h>
	#include <linux/spinlock.h>
	#include <linux/reset-controller.h>
	#include <dt-bindings/reset/cortina,gemini-reset.h>
	#include <dt-bindings/clock/cortina,gemini-clock.h>

	/* Globally visible clocks */
	static DEFINE_SPINLOCK(gemini_clk_lock);

	#define GEMINI_GLOBAL_STATUS 0x04
	#define PLL_OSC_SEL BIT(30)
	#define AHBSPEED_SHIFT (15)
	#define AHBSPEED_MASK 0x07
	#define CPU_AHB_RATIO_SHIFT (18)
	#define CPU_AHB_RATIO_MASK 0x03

	#define GEMINI_GLOBAL_PLL_CONTROL 0x08

	#define GEMINI_GLOBAL_SOFT_RESET 0x0c

	#define GEMINI_GLOBAL_MISC_CONTROL 0x30
	#define PCI_CLK_66MHZ BIT(18)

	#define GEMINI_GLOBAL_CLOCK_CONTROL 0x34
	#define PCI_CLKRUN_EN BIT(16)
	#define TVC_HALFDIV_SHIFT (24)
	#define TVC_HALFDIV_MASK 0x1f
	#define SECURITY_CLK_SEL BIT(29)

	#define GEMINI_GLOBAL_PCI_DLL_CONTROL 0x44
	#define PCI_DLL_BYPASS BIT(31)
	#define PCI_DLL_TAP_SEL_MASK 0x1f

	/**
	* struct gemini_data_data - Gemini gated clocks
	* @bit_idx: the bit used to gate this clock in the clock register
	* @name: the clock name
	* @parent_name: the name of the parent clock
	* @flags: standard clock framework flags
	*/
	struct gemini_gate_data {
	u8 bit_idx;
	const char *name;
	const char *parent_name;
	unsigned long flags;
	};

	/**
	* struct clk_gemini_pci - Gemini PCI clock
	* @hw: corresponding clock hardware entry
	* @map: regmap to access the registers
	* @rate: current rate
	*/
	struct clk_gemini_pci {
	struct clk_hw hw;
	struct regmap *map;
	unsigned long rate;
	};

	/**
	* struct gemini_reset - gemini reset controller
	* @map: regmap to access the containing system controller
	* @rcdev: reset controller device
	*/
	struct gemini_reset {
	struct regmap *map;
	struct reset_controller_dev rcdev;
	};

	/* Keeps track of all clocks */
	static struct clk_hw_onecell_data *gemini_clk_data;

	static const struct gemini_gate_data gemini_gates[] = {
	{ 1, "security-gate", "secdiv", 0 },
	{ 2, "gmac0-gate", "ahb", 0 },
	{ 3, "gmac1-gate", "ahb", 0 },
	{ 4, "sata0-gate", "ahb", 0 },
	{ 5, "sata1-gate", "ahb", 0 },
	{ 6, "usb0-gate", "ahb", 0 },
	{ 7, "usb1-gate", "ahb", 0 },
	{ 8, "ide-gate", "ahb", 0 },
	{ 9, "pci-gate", "ahb", 0 },
	/*
	* The DDR controller may never have a driver, but certainly must
	* not be gated off.
	*/
	{ 10, "ddr-gate", "ahb", CLK_IS_CRITICAL },
	/*
	* The flash controller must be on to access NOR flash through the
	* memory map.
	*/
	{ 11, "flash-gate", "ahb", CLK_IGNORE_UNUSED },
	{ 12, "tvc-gate", "ahb", 0 },
	{ 13, "boot-gate", "apb", 0 },
	};

	#define to_pciclk(_hw) container_of(_hw, struct clk_gemini_pci, hw)

	#define to_gemini_reset(p) container_of((p), struct gemini_reset, rcdev)

	static unsigned long gemini_pci_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct clk_gemini_pci *pciclk = to_pciclk(hw);
	u32 val;

	regmap_read(pciclk->map, GEMINI_GLOBAL_MISC_CONTROL, &val);
	if (val & PCI_CLK_66MHZ)
	return 66000000;
	return 33000000;
	}

	static long gemini_pci_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *prate)
	{
	/* We support 33 and 66 MHz */
	if (rate < 48000000)
	return 33000000;
	return 66000000;
	}

	static int gemini_pci_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct clk_gemini_pci *pciclk = to_pciclk(hw);

	if (rate == 33000000)
	return regmap_update_bits(pciclk->map,
	GEMINI_GLOBAL_MISC_CONTROL,
	PCI_CLK_66MHZ, 0);
	if (rate == 66000000)
	return regmap_update_bits(pciclk->map,
	GEMINI_GLOBAL_MISC_CONTROL,
	0, PCI_CLK_66MHZ);
	return -EINVAL;
	}

	static int gemini_pci_enable(struct clk_hw *hw)
	{
	struct clk_gemini_pci *pciclk = to_pciclk(hw);

	regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
	0, PCI_CLKRUN_EN);
	return 0;
	}

	static void gemini_pci_disable(struct clk_hw *hw)
	{
	struct clk_gemini_pci *pciclk = to_pciclk(hw);

	regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
	PCI_CLKRUN_EN, 0);
	}

	static int gemini_pci_is_enabled(struct clk_hw *hw)
	{
	struct clk_gemini_pci *pciclk = to_pciclk(hw);
	unsigned int val;

	regmap_read(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
	return !!(val & PCI_CLKRUN_EN);
	}

	static const struct clk_ops gemini_pci_clk_ops = {
	.recalc_rate = gemini_pci_recalc_rate,
	.round_rate = gemini_pci_round_rate,
	.set_rate = gemini_pci_set_rate,
	.enable = gemini_pci_enable,
	.disable = gemini_pci_disable,
	.is_enabled = gemini_pci_is_enabled,
	};

	static struct clk_hw gemini_pci_clk_setup(const char name,
	const char *parent_name,
	struct regmap *map)
	{
	struct clk_gemini_pci *pciclk;
	struct clk_init_data init;
	int ret;

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

	init.name = name;
	init.ops = &gemini_pci_clk_ops;
	init.flags = 0;
	init.parent_names = &parent_name;
	init.num_parents = 1;
	pciclk->map = map;
	pciclk->hw.init = &init;

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

	return &pciclk->hw;
	}

	/*
	* This is a self-deasserting reset controller.
	*/
	static int gemini_reset(struct reset_controller_dev *rcdev,
	unsigned long id)
	{
	struct gemini_reset *gr = to_gemini_reset(rcdev);

	/* Manual says to always set BIT 30 (CPU1) to 1 */
	return regmap_write(gr->map,
	GEMINI_GLOBAL_SOFT_RESET,
	BIT(GEMINI_RESET_CPU1) \| BIT(id));
	}

	static int gemini_reset_assert(struct reset_controller_dev *rcdev,
	unsigned long id)
	{
	return 0;
	}

	static int gemini_reset_deassert(struct reset_controller_dev *rcdev,
	unsigned long id)
	{
	return 0;
	}

	static int gemini_reset_status(struct reset_controller_dev *rcdev,
	unsigned long id)
	{
	struct gemini_reset *gr = to_gemini_reset(rcdev);
	u32 val;
	int ret;

	ret = regmap_read(gr->map, GEMINI_GLOBAL_SOFT_RESET, &val);
	if (ret)
	return ret;

	return !!(val & BIT(id));
	}

	static const struct reset_control_ops gemini_reset_ops = {
	.reset = gemini_reset,
	.assert = gemini_reset_assert,
	.deassert = gemini_reset_deassert,
	.status = gemini_reset_status,
	};

	static int gemini_clk_probe(struct platform_device *pdev)
	{
	/* Gives the fracions 1x, 1.5x, 1.85x and 2x */
	unsigned int cpu_ahb_mult[4] = { 1, 3, 24, 2 };
	unsigned int cpu_ahb_div[4] = { 1, 2, 13, 1 };
	void __iomem *base;
	struct gemini_reset *gr;
	struct regmap *map;
	struct clk_hw *hw;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	unsigned int mult, div;
	struct resource *res;
	u32 val;
	int ret;
	int i;

	gr = devm_kzalloc(dev, sizeof(*gr), GFP_KERNEL);
	if (!gr)
	return -ENOMEM;

	/* Remap the system controller for the exclusive register */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(dev, res);
	if (IS_ERR(base))
	return PTR_ERR(base);

	map = syscon_node_to_regmap(np);
	if (IS_ERR(map)) {
	dev_err(dev, "no syscon regmap\n");
	return PTR_ERR(map);
	}

	gr->map = map;
	gr->rcdev.owner = THIS_MODULE;
	gr->rcdev.nr_resets = 32;
	gr->rcdev.ops = &gemini_reset_ops;
	gr->rcdev.of_node = np;

	ret = devm_reset_controller_register(dev, &gr->rcdev);
	if (ret) {
	dev_err(dev, "could not register reset controller\n");
	return ret;
	}

	/* RTC clock 32768 Hz */
	hw = clk_hw_register_fixed_rate(NULL, "rtc", NULL, 0, 32768);
	gemini_clk_data->hws[GEMINI_CLK_RTC] = hw;

	/* CPU clock derived as a fixed ratio from the AHB clock */
	regmap_read(map, GEMINI_GLOBAL_STATUS, &val);
	val >>= CPU_AHB_RATIO_SHIFT;
	val &= CPU_AHB_RATIO_MASK;
	hw = clk_hw_register_fixed_factor(NULL, "cpu", "ahb", 0,
	cpu_ahb_mult[val],
	cpu_ahb_div[val]);
	gemini_clk_data->hws[GEMINI_CLK_CPU] = hw;

	/* Security clock is 1:1 or 0.75 of APB */
	regmap_read(map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
	if (val & SECURITY_CLK_SEL) {
	mult = 1;
	div = 1;
	} else {
	mult = 3;
	div = 4;
	}
	hw = clk_hw_register_fixed_factor(NULL, "secdiv", "ahb", 0, mult, div);

	/*
	* These are the leaf gates, at boot no clocks are gated.
	*/
	for (i = 0; i < ARRAY_SIZE(gemini_gates); i++) {
	const struct gemini_gate_data *gd;

	gd = &gemini_gates[i];
	gemini_clk_data->hws[GEMINI_CLK_GATES + i] =
	clk_hw_register_gate(NULL, gd->name,
	gd->parent_name,
	gd->flags,
	base + GEMINI_GLOBAL_CLOCK_CONTROL,
	gd->bit_idx,
	CLK_GATE_SET_TO_DISABLE,
	&gemini_clk_lock);
	}

	/*
	* The TV Interface Controller has a 5-bit half divider register.
	* This clock is supposed to be 27MHz as this is an exact multiple
	* of PAL and NTSC frequencies. The register is undocumented :(
	* FIXME: figure out the parent and how the divider works.
	*/
	mult = 1;
	div = ((val >> TVC_HALFDIV_SHIFT) & TVC_HALFDIV_MASK);
	dev_dbg(dev, "TVC half divider value = %d\n", div);
	div += 1;
	hw = clk_hw_register_fixed_rate(NULL, "tvcdiv", "xtal", 0, 27000000);
	gemini_clk_data->hws[GEMINI_CLK_TVC] = hw;

	/* FIXME: very unclear what the parent is */
	hw = gemini_pci_clk_setup("PCI", "xtal", map);
	gemini_clk_data->hws[GEMINI_CLK_PCI] = hw;

	/* FIXME: very unclear what the parent is */
	hw = clk_hw_register_fixed_rate(NULL, "uart", "xtal", 0, 48000000);
	gemini_clk_data->hws[GEMINI_CLK_UART] = hw;

	return 0;
	}

	static const struct of_device_id gemini_clk_dt_ids[] = {
	{ .compatible = "cortina,gemini-syscon", },
	{ /* sentinel */ },
	};

	static struct platform_driver gemini_clk_driver = {
	.probe = gemini_clk_probe,
	.driver = {
	.name = "gemini-clk",
	.of_match_table = gemini_clk_dt_ids,
	.suppress_bind_attrs = true,
	},
	};
	builtin_platform_driver(gemini_clk_driver);

	static void __init gemini_cc_init(struct device_node *np)
	{
	struct regmap *map;
	struct clk_hw *hw;
	unsigned long freq;
	unsigned int mult, div;
	u32 val;
	int ret;
	int i;

	gemini_clk_data = kzalloc(struct_size(gemini_clk_data, hws,
	GEMINI_NUM_CLKS),
	GFP_KERNEL);
	if (!gemini_clk_data)
	return;

	/*
	* This way all clock fetched before the platform device probes,
	* except those we assign here for early use, will be deferred.
	*/
	for (i = 0; i < GEMINI_NUM_CLKS; i++)
	gemini_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);

	map = syscon_node_to_regmap(np);
	if (IS_ERR(map)) {
	pr_err("no syscon regmap\n");
	return;
	}
	/*
	* We check that the regmap works on this very first access,
	* but as this is an MMIO-backed regmap, subsequent regmap
	* access is not going to fail and we skip error checks from
	* this point.
	*/
	ret = regmap_read(map, GEMINI_GLOBAL_STATUS, &val);
	if (ret) {
	pr_err("failed to read global status register\n");
	return;
	}

	/*
	* XTAL is the crystal oscillator, 60 or 30 MHz selected from
	* strap pin E6
	*/
	if (val & PLL_OSC_SEL)
	freq = 30000000;
	else
	freq = 60000000;
	hw = clk_hw_register_fixed_rate(NULL, "xtal", NULL, 0, freq);
	pr_debug("main crystal @%lu MHz\n", freq / 1000000);

	/* VCO clock derived from the crystal */
	mult = 13 + ((val >> AHBSPEED_SHIFT) & AHBSPEED_MASK);
	div = 2;
	/* If we run on 30 MHz crystal we have to multiply with two */
	if (val & PLL_OSC_SEL)
	mult *= 2;
	hw = clk_hw_register_fixed_factor(NULL, "vco", "xtal", 0, mult, div);

	/* The AHB clock is always 1/3 of the VCO */
	hw = clk_hw_register_fixed_factor(NULL, "ahb", "vco", 0, 1, 3);
	gemini_clk_data->hws[GEMINI_CLK_AHB] = hw;

	/* The APB clock is always 1/6 of the AHB */
	hw = clk_hw_register_fixed_factor(NULL, "apb", "ahb", 0, 1, 6);
	gemini_clk_data->hws[GEMINI_CLK_APB] = hw;

	/* Register the clocks to be accessed by the device tree */
	gemini_clk_data->num = GEMINI_NUM_CLKS;
	of_clk_add_hw_provider(np, of_clk_hw_onecell_get, gemini_clk_data);
	}
	CLK_OF_DECLARE_DRIVER(gemini_cc, "cortina,gemini-syscon", gemini_cc_init);