--- /dev/null
+/*
+ * 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(unsigned int irq, struct irq_desc *desc)
+{
+ struct pmu_data *pmu = irq_get_handler_data(irq);
+ 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(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);
+ }
+ pm_genpd_poweroff_unused();
+
+ /* 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;
+}
projects / karo-tx-linux.git / commitdiff