| // 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); |