117 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			117 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * Copyright (c) 2017 Intel Corporation
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|  */
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| #include <common.h>
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| #include <dm.h>
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| #include <regmap.h>
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| #include <syscon.h>
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| #include <asm/cpu.h>
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| #include <asm/pmu.h>
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| #include <linux/errno.h>
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| #include <linux/io.h>
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| 
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| /* Registers */
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| struct pmu_regs {
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| 	u32	sts;
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| 	u32	cmd;
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| 	u32	ics;
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| 	u32	reserved;
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| 	u32	wkc[4];
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| 	u32	wks[4];
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| 	u32	ssc[4];
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| 	u32	sss[4];
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| };
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| 
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| /* Bits in PMU_REGS_STS */
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| #define PMU_REGS_STS_BUSY		(1 << 8)
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| 
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| struct pmu_mid {
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| 	struct pmu_regs *regs;
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| };
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| 
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| static int pmu_read_status(struct pmu_regs *regs)
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| {
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| 	int retry = 500000;
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| 	u32 val;
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| 
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| 	do {
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| 		val = readl(®s->sts);
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| 		if (!(val & PMU_REGS_STS_BUSY))
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| 			return 0;
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| 
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| 		udelay(1);
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| 	} while (--retry);
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| 
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| 	printf("WARNING: PMU still busy\n");
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| 	return -EBUSY;
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| }
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| 
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| static int pmu_power_lss(struct pmu_regs *regs, unsigned int lss, bool on)
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| {
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| 	unsigned int offset = (lss * 2) / 32;
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| 	unsigned int shift = (lss * 2) % 32;
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| 	u32 ssc;
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| 	int ret;
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| 
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| 	/* Check PMU status */
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| 	ret = pmu_read_status(regs);
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| 	if (ret)
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| 		return ret;
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| 
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| 	/* Read PMU values */
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| 	ssc = readl(®s->sss[offset]);
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| 
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| 	/* Modify PMU values */
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| 	if (on)
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| 		ssc &= ~(0x3 << shift);		/* D0 */
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| 	else
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| 		ssc |= 0x3 << shift;		/* D3hot */
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| 
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| 	/* Write modified PMU values */
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| 	writel(ssc, ®s->ssc[offset]);
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| 
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| 	/* Update modified PMU values */
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| 	writel(0x00002201, ®s->cmd);
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| 
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| 	/* Check PMU status */
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| 	return pmu_read_status(regs);
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| }
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| 
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| int pmu_turn_power(unsigned int lss, bool on)
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| {
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| 	struct pmu_mid *pmu;
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| 	struct udevice *dev;
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| 	int ret;
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| 
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| 	ret = syscon_get_by_driver_data(X86_SYSCON_PMU, &dev);
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| 	if (ret)
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| 		return ret;
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| 
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| 	pmu = dev_get_priv(dev);
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| 
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| 	return pmu_power_lss(pmu->regs, lss, on);
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| }
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| 
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| static int pmu_mid_probe(struct udevice *dev)
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| {
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| 	struct pmu_mid *pmu = dev_get_priv(dev);
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| 
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| 	pmu->regs = syscon_get_first_range(X86_SYSCON_PMU);
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| 
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| 	return 0;
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| }
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| 
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| static const struct udevice_id pmu_mid_match[] = {
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| 	{ .compatible = "intel,pmu-mid", .data = X86_SYSCON_PMU },
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| 	{ /* sentinel */ }
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| };
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| 
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| U_BOOT_DRIVER(intel_mid_pmu) = {
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| 	.name		= "pmu_mid",
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| 	.id		= UCLASS_SYSCON,
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| 	.of_match	= pmu_mid_match,
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| 	.probe		= pmu_mid_probe,
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| 	.priv_auto_alloc_size = sizeof(struct pmu_mid),
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| };
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