diff options
Diffstat (limited to 'kernel/drivers/soc/dove/pmu.c')
| -rw-r--r-- | kernel/drivers/soc/dove/pmu.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/kernel/drivers/soc/dove/pmu.c b/kernel/drivers/soc/dove/pmu.c new file mode 100644 index 000000000..abd087917 --- /dev/null +++ b/kernel/drivers/soc/dove/pmu.c @@ -0,0 +1,411 @@ +/* + * Marvell Dove PMU support + */ +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/pm_domain.h> +#include <linux/reset.h> +#include <linux/reset-controller.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/soc/dove/pmu.h> +#include <linux/spinlock.h> + +#define NR_PMU_IRQS 7 + +#define PMC_SW_RST 0x30 +#define PMC_IRQ_CAUSE 0x50 +#define PMC_IRQ_MASK 0x54 + +#define PMU_PWR 0x10 +#define PMU_ISO 0x58 + +struct pmu_data { + spinlock_t lock; + struct device_node *of_node; + void __iomem *pmc_base; + void __iomem *pmu_base; + struct irq_chip_generic *irq_gc; + struct irq_domain *irq_domain; +#ifdef CONFIG_RESET_CONTROLLER + struct reset_controller_dev reset; +#endif +}; + +/* + * The PMU contains a register to reset various subsystems within the + * SoC. Export this as a reset controller. + */ +#ifdef CONFIG_RESET_CONTROLLER +#define rcdev_to_pmu(rcdev) container_of(rcdev, struct pmu_data, reset) + +static int pmu_reset_reset(struct reset_controller_dev *rc, unsigned long id) +{ + struct pmu_data *pmu = rcdev_to_pmu(rc); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&pmu->lock, flags); + val = readl_relaxed(pmu->pmc_base + PMC_SW_RST); + writel_relaxed(val & ~BIT(id), pmu->pmc_base + PMC_SW_RST); + writel_relaxed(val | BIT(id), pmu->pmc_base + PMC_SW_RST); + spin_unlock_irqrestore(&pmu->lock, flags); + + return 0; +} + +static int pmu_reset_assert(struct reset_controller_dev *rc, unsigned long id) +{ + struct pmu_data *pmu = rcdev_to_pmu(rc); + unsigned long flags; + u32 val = ~BIT(id); + + spin_lock_irqsave(&pmu->lock, flags); + val &= readl_relaxed(pmu->pmc_base + PMC_SW_RST); + writel_relaxed(val, pmu->pmc_base + PMC_SW_RST); + spin_unlock_irqrestore(&pmu->lock, flags); + + return 0; +} + +static int pmu_reset_deassert(struct reset_controller_dev *rc, unsigned long id) +{ + struct pmu_data *pmu = rcdev_to_pmu(rc); + unsigned long flags; + u32 val = BIT(id); + + spin_lock_irqsave(&pmu->lock, flags); + val |= readl_relaxed(pmu->pmc_base + PMC_SW_RST); + writel_relaxed(val, pmu->pmc_base + PMC_SW_RST); + spin_unlock_irqrestore(&pmu->lock, flags); + + return 0; +} + +static struct reset_control_ops pmu_reset_ops = { + .reset = pmu_reset_reset, + .assert = pmu_reset_assert, + .deassert = pmu_reset_deassert, +}; + +static struct reset_controller_dev pmu_reset __initdata = { + .ops = &pmu_reset_ops, + .owner = THIS_MODULE, + .nr_resets = 32, +}; + +static void __init pmu_reset_init(struct pmu_data *pmu) +{ + int ret; + + pmu->reset = pmu_reset; + pmu->reset.of_node = pmu->of_node; + + ret = reset_controller_register(&pmu->reset); + if (ret) + pr_err("pmu: %s failed: %d\n", "reset_controller_register", ret); +} +#else +static void __init pmu_reset_init(struct pmu_data *pmu) +{ +} +#endif + +struct pmu_domain { + struct pmu_data *pmu; + u32 pwr_mask; + u32 rst_mask; + u32 iso_mask; + struct generic_pm_domain base; +}; + +#define to_pmu_domain(dom) container_of(dom, struct pmu_domain, base) + +/* + * This deals with the "old" Marvell sequence of bringing a power domain + * down/up, which is: apply power, release reset, disable isolators. + * + * Later devices apparantly use a different sequence: power up, disable + * isolators, assert repair signal, enable SRMA clock, enable AXI clock, + * enable module clock, deassert reset. + * + * Note: reading the assembly, it seems that the IO accessors have an + * unfortunate side-effect - they cause memory already read into registers + * for the if () to be re-read for the bit-set or bit-clear operation. + * The code is written to avoid this. + */ +static int pmu_domain_power_off(struct generic_pm_domain *domain) +{ + struct pmu_domain *pmu_dom = to_pmu_domain(domain); + struct pmu_data *pmu = pmu_dom->pmu; + unsigned long flags; + unsigned int val; + void __iomem *pmu_base = pmu->pmu_base; + void __iomem *pmc_base = pmu->pmc_base; + + spin_lock_irqsave(&pmu->lock, flags); + + /* Enable isolators */ + if (pmu_dom->iso_mask) { + val = ~pmu_dom->iso_mask; + val &= readl_relaxed(pmu_base + PMU_ISO); + writel_relaxed(val, pmu_base + PMU_ISO); + } + + /* Reset unit */ + if (pmu_dom->rst_mask) { + val = ~pmu_dom->rst_mask; + val &= readl_relaxed(pmc_base + PMC_SW_RST); + writel_relaxed(val, pmc_base + PMC_SW_RST); + } + + /* Power down */ + val = readl_relaxed(pmu_base + PMU_PWR) | pmu_dom->pwr_mask; + writel_relaxed(val, pmu_base + PMU_PWR); + + spin_unlock_irqrestore(&pmu->lock, flags); + + return 0; +} + +static int pmu_domain_power_on(struct generic_pm_domain *domain) +{ + struct pmu_domain *pmu_dom = to_pmu_domain(domain); + struct pmu_data *pmu = pmu_dom->pmu; + unsigned long flags; + unsigned int val; + void __iomem *pmu_base = pmu->pmu_base; + void __iomem *pmc_base = pmu->pmc_base; + + spin_lock_irqsave(&pmu->lock, flags); + + /* Power on */ + val = ~pmu_dom->pwr_mask & readl_relaxed(pmu_base + PMU_PWR); + writel_relaxed(val, pmu_base + PMU_PWR); + + /* Release reset */ + if (pmu_dom->rst_mask) { + val = pmu_dom->rst_mask; + val |= readl_relaxed(pmc_base + PMC_SW_RST); + writel_relaxed(val, pmc_base + PMC_SW_RST); + } + + /* Disable isolators */ + if (pmu_dom->iso_mask) { + val = pmu_dom->iso_mask; + val |= readl_relaxed(pmu_base + PMU_ISO); + writel_relaxed(val, pmu_base + PMU_ISO); + } + + spin_unlock_irqrestore(&pmu->lock, flags); + + return 0; +} + +static void __pmu_domain_register(struct pmu_domain *domain, + struct device_node *np) +{ + unsigned int val = readl_relaxed(domain->pmu->pmu_base + PMU_PWR); + + domain->base.power_off = pmu_domain_power_off; + domain->base.power_on = pmu_domain_power_on; + + pm_genpd_init(&domain->base, NULL, !(val & domain->pwr_mask)); + + if (np) + of_genpd_add_provider_simple(np, &domain->base); +} + +/* PMU IRQ controller */ +static void pmu_irq_handler(struct irq_desc *desc) +{ + struct pmu_data *pmu = irq_desc_get_handler_data(desc); + struct irq_chip_generic *gc = pmu->irq_gc; + struct irq_domain *domain = pmu->irq_domain; + void __iomem *base = gc->reg_base; + u32 stat = readl_relaxed(base + PMC_IRQ_CAUSE) & gc->mask_cache; + u32 done = ~0; + + if (stat == 0) { + handle_bad_irq(desc); + return; + } + + while (stat) { + u32 hwirq = fls(stat) - 1; + + stat &= ~(1 << hwirq); + done &= ~(1 << hwirq); + + generic_handle_irq(irq_find_mapping(domain, hwirq)); + } + + /* + * The PMU mask register is not RW0C: it is RW. This means that + * the bits take whatever value is written to them; if you write + * a '1', you will set the interrupt. + * + * Unfortunately this means there is NO race free way to clear + * these interrupts. + * + * So, let's structure the code so that the window is as small as + * possible. + */ + irq_gc_lock(gc); + done &= readl_relaxed(base + PMC_IRQ_CAUSE); + writel_relaxed(done, base + PMC_IRQ_CAUSE); + irq_gc_unlock(gc); +} + +static int __init dove_init_pmu_irq(struct pmu_data *pmu, int irq) +{ + const char *name = "pmu_irq"; + struct irq_chip_generic *gc; + struct irq_domain *domain; + int ret; + + /* mask and clear all interrupts */ + writel(0, pmu->pmc_base + PMC_IRQ_MASK); + writel(0, pmu->pmc_base + PMC_IRQ_CAUSE); + + domain = irq_domain_add_linear(pmu->of_node, NR_PMU_IRQS, + &irq_generic_chip_ops, NULL); + if (!domain) { + pr_err("%s: unable to add irq domain\n", name); + return -ENOMEM; + } + + ret = irq_alloc_domain_generic_chips(domain, NR_PMU_IRQS, 1, name, + handle_level_irq, + IRQ_NOREQUEST | IRQ_NOPROBE, 0, + IRQ_GC_INIT_MASK_CACHE); + if (ret) { + pr_err("%s: unable to alloc irq domain gc: %d\n", name, ret); + irq_domain_remove(domain); + return ret; + } + + gc = irq_get_domain_generic_chip(domain, 0); + gc->reg_base = pmu->pmc_base; + gc->chip_types[0].regs.mask = PMC_IRQ_MASK; + gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit; + gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit; + + pmu->irq_domain = domain; + pmu->irq_gc = gc; + + irq_set_handler_data(irq, pmu); + irq_set_chained_handler(irq, pmu_irq_handler); + + return 0; +} + +/* + * pmu: power-manager@d0000 { + * compatible = "marvell,dove-pmu"; + * reg = <0xd0000 0x8000> <0xd8000 0x8000>; + * interrupts = <33>; + * interrupt-controller; + * #reset-cells = 1; + * vpu_domain: vpu-domain { + * #power-domain-cells = <0>; + * marvell,pmu_pwr_mask = <0x00000008>; + * marvell,pmu_iso_mask = <0x00000001>; + * resets = <&pmu 16>; + * }; + * gpu_domain: gpu-domain { + * #power-domain-cells = <0>; + * marvell,pmu_pwr_mask = <0x00000004>; + * marvell,pmu_iso_mask = <0x00000002>; + * resets = <&pmu 18>; + * }; + * }; + */ +int __init dove_init_pmu(void) +{ + struct device_node *np_pmu, *domains_node, *np; + struct pmu_data *pmu; + int ret, parent_irq; + + /* Lookup the PMU node */ + np_pmu = of_find_compatible_node(NULL, NULL, "marvell,dove-pmu"); + if (!np_pmu) + return 0; + + domains_node = of_get_child_by_name(np_pmu, "domains"); + if (!domains_node) { + pr_err("%s: failed to find domains sub-node\n", np_pmu->name); + return 0; + } + + pmu = kzalloc(sizeof(*pmu), GFP_KERNEL); + if (!pmu) + return -ENOMEM; + + spin_lock_init(&pmu->lock); + pmu->of_node = np_pmu; + pmu->pmc_base = of_iomap(pmu->of_node, 0); + pmu->pmu_base = of_iomap(pmu->of_node, 1); + if (!pmu->pmc_base || !pmu->pmu_base) { + pr_err("%s: failed to map PMU\n", np_pmu->name); + iounmap(pmu->pmu_base); + iounmap(pmu->pmc_base); + kfree(pmu); + return -ENOMEM; + } + + pmu_reset_init(pmu); + + for_each_available_child_of_node(domains_node, np) { + struct of_phandle_args args; + struct pmu_domain *domain; + + domain = kzalloc(sizeof(*domain), GFP_KERNEL); + if (!domain) + break; + + domain->pmu = pmu; + domain->base.name = kstrdup(np->name, GFP_KERNEL); + if (!domain->base.name) { + kfree(domain); + break; + } + + of_property_read_u32(np, "marvell,pmu_pwr_mask", + &domain->pwr_mask); + of_property_read_u32(np, "marvell,pmu_iso_mask", + &domain->iso_mask); + + /* + * We parse the reset controller property directly here + * to ensure that we can operate when the reset controller + * support is not configured into the kernel. + */ + ret = of_parse_phandle_with_args(np, "resets", "#reset-cells", + 0, &args); + if (ret == 0) { + if (args.np == pmu->of_node) + domain->rst_mask = BIT(args.args[0]); + of_node_put(args.np); + } + + __pmu_domain_register(domain, np); + } + + /* Loss of the interrupt controller is not a fatal error. */ + parent_irq = irq_of_parse_and_map(pmu->of_node, 0); + if (!parent_irq) { + pr_err("%s: no interrupt specified\n", np_pmu->name); + } else { + ret = dove_init_pmu_irq(pmu, parent_irq); + if (ret) + pr_err("dove_init_pmu_irq() failed: %d\n", ret); + } + + return 0; +} |