This simple PMU driver allows to tyrn power on and off for selected devices. In particularly Intel Tangier needs to power on SDHCI controllers in order to access to them during board initialization.
In the future it might be expanded to cover other Intel MID platforms, that's why it's located under arch/x86/lib and called pmu.c.
Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com --- arch/x86/include/asm/cpu.h | 1 + arch/x86/include/asm/pmu.h | 11 +++++ arch/x86/lib/Makefile | 1 + arch/x86/lib/pmu.c | 117 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 130 insertions(+) create mode 100644 arch/x86/include/asm/pmu.h create mode 100644 arch/x86/lib/pmu.c
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 0ee13b1eb1..c00687a20a 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -54,6 +54,7 @@ enum { X86_NONE, X86_SYSCON_ME, /* Intel Management Engine */ X86_SYSCON_PINCONF, /* Intel x86 pin configuration */ + X86_SYSCON_PMU, /* Power Management Unit */ X86_SYSCON_SCU, /* System Controller Unit */ };
diff --git a/arch/x86/include/asm/pmu.h b/arch/x86/include/asm/pmu.h new file mode 100644 index 0000000000..96b968ff8f --- /dev/null +++ b/arch/x86/include/asm/pmu.h @@ -0,0 +1,11 @@ +/* + * Copyright (c) 2017 Intel Corporation + * + * SPDX-License-Identifier: GPL-2.0+ + */ +#ifndef _X86_ASM_PMU_IPC_H_ +#define _X86_ASM_PMU_IPC_H_ + +int pmu_turn_power(unsigned int lss, bool on); + +#endif /* _X86_ASM_PMU_IPC_H_ */ diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 320e45e4a0..d1ad37af64 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -31,6 +31,7 @@ obj-y += pinctrl_ich6.o obj-y += pirq_routing.o obj-y += relocate.o obj-y += physmem.o +obj-$(CONFIG_INTEL_MID) += pmu.o obj-$(CONFIG_X86_RAMTEST) += ramtest.o obj-$(CONFIG_INTEL_MID) += scu.o obj-y += sections.o diff --git a/arch/x86/lib/pmu.c b/arch/x86/lib/pmu.c new file mode 100644 index 0000000000..4ceab8dc64 --- /dev/null +++ b/arch/x86/lib/pmu.c @@ -0,0 +1,117 @@ +/* + * Copyright (c) 2017 Intel Corporation + * + * SPDX-License-Identifier: GPL-2.0+ + */ +#include <common.h> +#include <dm.h> +#include <regmap.h> +#include <syscon.h> +#include <asm/cpu.h> +#include <asm/pmu.h> +#include <linux/errno.h> +#include <linux/io.h> + +/* Registers */ +struct pmu_regs { + u32 sts; + u32 cmd; + u32 ics; + u32 reserved; + u32 wkc[4]; + u32 wks[4]; + u32 ssc[4]; + u32 sss[4]; +}; + +/* Bits in PMU_REGS_STS */ +#define PMU_REGS_STS_BUSY (1 << 8) + +struct pmu_mid { + struct pmu_regs *regs; +}; + +static int pmu_read_status(struct pmu_regs *regs) +{ + int retry = 500000; + u32 val; + + do { + val = readl(®s->sts); + if (!(val & PMU_REGS_STS_BUSY)) + return 0; + + udelay(1); + } while (--retry); + + printf("WARNING: PMU still busy\n"); + return -EBUSY; +} + +static int pmu_power_lss(struct pmu_regs *regs, unsigned int lss, bool on) +{ + unsigned int offset = (lss * 2) / 32; + unsigned int shift = (lss * 2) % 32; + u32 ssc; + int ret; + + /* Check PMU status */ + ret = pmu_read_status(regs); + if (ret) + return ret; + + /* Read PMU values */ + ssc = readl(®s->sss[offset]); + + /* Modify PMU values */ + if (on) + ssc &= ~(0x3 << shift); /* D0 */ + else + ssc |= 0x3 << shift; /* D3hot */ + + /* Write modified PMU values */ + writel(ssc, ®s->ssc[offset]); + + /* Update modified PMU values */ + writel(0x00002201, ®s->cmd); + + /* Check PMU status */ + return pmu_read_status(regs); +} + +int pmu_turn_power(unsigned int lss, bool on) +{ + struct pmu_mid *pmu; + struct udevice *dev; + int ret; + + ret = syscon_get_by_driver_data(X86_SYSCON_PMU, &dev); + if (ret) + return ret; + + pmu = dev_get_priv(dev); + + return pmu_power_lss(pmu->regs, lss, on); +} + +static int pmu_mid_probe(struct udevice *dev) +{ + struct pmu_mid *pmu = dev_get_priv(dev); + + pmu->regs = syscon_get_first_range(X86_SYSCON_PMU); + + return 0; +} + +static const struct udevice_id pmu_mid_match[] = { + { .compatible = "intel,pmu-mid", .data = X86_SYSCON_PMU }, + { /* sentinel */ } +}; + +U_BOOT_DRIVER(intel_mid_pmu) = { + .name = "pmu_mid", + .id = UCLASS_SYSCON, + .of_match = pmu_mid_match, + .probe = pmu_mid_probe, + .priv_auto_alloc_size = sizeof(struct pmu_mid), +};