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path: root/drivers/soc/renesas/rcar-sysc.c
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Diffstat (limited to 'drivers/soc/renesas/rcar-sysc.c')
-rw-r--r--drivers/soc/renesas/rcar-sysc.c401
1 files changed, 401 insertions, 0 deletions
diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c
new file mode 100644
index 000000000000..79dbc770895f
--- /dev/null
+++ b/drivers/soc/renesas/rcar-sysc.c
@@ -0,0 +1,401 @@
+/*
+ * R-Car SYSC Power management support
+ *
+ * Copyright (C) 2014 Magnus Damm
+ * Copyright (C) 2015-2016 Glider bvba
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/clk/renesas.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/of_address.h>
+#include <linux/pm_domain.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/soc/renesas/rcar-sysc.h>
+
+#include "rcar-sysc.h"
+
+/* SYSC Common */
+#define SYSCSR 0x00 /* SYSC Status Register */
+#define SYSCISR 0x04 /* Interrupt Status Register */
+#define SYSCISCR 0x08 /* Interrupt Status Clear Register */
+#define SYSCIER 0x0c /* Interrupt Enable Register */
+#define SYSCIMR 0x10 /* Interrupt Mask Register */
+
+/* SYSC Status Register */
+#define SYSCSR_PONENB 1 /* Ready for power resume requests */
+#define SYSCSR_POFFENB 0 /* Ready for power shutoff requests */
+
+/*
+ * Power Control Register Offsets inside the register block for each domain
+ * Note: The "CR" registers for ARM cores exist on H1 only
+ * Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
+ * Use PSCI on R-Car Gen3
+ */
+#define PWRSR_OFFS 0x00 /* Power Status Register */
+#define PWROFFCR_OFFS 0x04 /* Power Shutoff Control Register */
+#define PWROFFSR_OFFS 0x08 /* Power Shutoff Status Register */
+#define PWRONCR_OFFS 0x0c /* Power Resume Control Register */
+#define PWRONSR_OFFS 0x10 /* Power Resume Status Register */
+#define PWRER_OFFS 0x14 /* Power Shutoff/Resume Error */
+
+
+#define SYSCSR_RETRIES 100
+#define SYSCSR_DELAY_US 1
+
+#define PWRER_RETRIES 100
+#define PWRER_DELAY_US 1
+
+#define SYSCISR_RETRIES 1000
+#define SYSCISR_DELAY_US 1
+
+#define RCAR_PD_ALWAYS_ON 32 /* Always-on power area */
+
+static void __iomem *rcar_sysc_base;
+static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
+
+static int rcar_sysc_pwr_on_off(const struct rcar_sysc_ch *sysc_ch, bool on)
+{
+ unsigned int sr_bit, reg_offs;
+ int k;
+
+ if (on) {
+ sr_bit = SYSCSR_PONENB;
+ reg_offs = PWRONCR_OFFS;
+ } else {
+ sr_bit = SYSCSR_POFFENB;
+ reg_offs = PWROFFCR_OFFS;
+ }
+
+ /* Wait until SYSC is ready to accept a power request */
+ for (k = 0; k < SYSCSR_RETRIES; k++) {
+ if (ioread32(rcar_sysc_base + SYSCSR) & BIT(sr_bit))
+ break;
+ udelay(SYSCSR_DELAY_US);
+ }
+
+ if (k == SYSCSR_RETRIES)
+ return -EAGAIN;
+
+ /* Submit power shutoff or power resume request */
+ iowrite32(BIT(sysc_ch->chan_bit),
+ rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
+
+ return 0;
+}
+
+static int rcar_sysc_power(const struct rcar_sysc_ch *sysc_ch, bool on)
+{
+ unsigned int isr_mask = BIT(sysc_ch->isr_bit);
+ unsigned int chan_mask = BIT(sysc_ch->chan_bit);
+ unsigned int status;
+ unsigned long flags;
+ int ret = 0;
+ int k;
+
+ spin_lock_irqsave(&rcar_sysc_lock, flags);
+
+ iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
+
+ /* Submit power shutoff or resume request until it was accepted */
+ for (k = 0; k < PWRER_RETRIES; k++) {
+ ret = rcar_sysc_pwr_on_off(sysc_ch, on);
+ if (ret)
+ goto out;
+
+ status = ioread32(rcar_sysc_base +
+ sysc_ch->chan_offs + PWRER_OFFS);
+ if (!(status & chan_mask))
+ break;
+
+ udelay(PWRER_DELAY_US);
+ }
+
+ if (k == PWRER_RETRIES) {
+ ret = -EIO;
+ goto out;
+ }
+
+ /* Wait until the power shutoff or resume request has completed * */
+ for (k = 0; k < SYSCISR_RETRIES; k++) {
+ if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
+ break;
+ udelay(SYSCISR_DELAY_US);
+ }
+
+ if (k == SYSCISR_RETRIES)
+ ret = -EIO;
+
+ iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
+
+ out:
+ spin_unlock_irqrestore(&rcar_sysc_lock, flags);
+
+ pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
+ sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
+ return ret;
+}
+
+int rcar_sysc_power_down(const struct rcar_sysc_ch *sysc_ch)
+{
+ return rcar_sysc_power(sysc_ch, false);
+}
+
+int rcar_sysc_power_up(const struct rcar_sysc_ch *sysc_ch)
+{
+ return rcar_sysc_power(sysc_ch, true);
+}
+
+static bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch)
+{
+ unsigned int st;
+
+ st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
+ if (st & BIT(sysc_ch->chan_bit))
+ return true;
+
+ return false;
+}
+
+void __iomem *rcar_sysc_init(phys_addr_t base)
+{
+ rcar_sysc_base = ioremap_nocache(base, PAGE_SIZE);
+ if (!rcar_sysc_base)
+ panic("unable to ioremap R-Car SYSC hardware block\n");
+
+ return rcar_sysc_base;
+}
+
+struct rcar_sysc_pd {
+ struct generic_pm_domain genpd;
+ struct rcar_sysc_ch ch;
+ unsigned int flags;
+ char name[0];
+};
+
+static inline struct rcar_sysc_pd *to_rcar_pd(struct generic_pm_domain *d)
+{
+ return container_of(d, struct rcar_sysc_pd, genpd);
+}
+
+static int rcar_sysc_pd_power_off(struct generic_pm_domain *genpd)
+{
+ struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
+
+ pr_debug("%s: %s\n", __func__, genpd->name);
+
+ if (pd->flags & PD_NO_CR) {
+ pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
+ return -EBUSY;
+ }
+
+ if (pd->flags & PD_BUSY) {
+ pr_debug("%s: %s busy\n", __func__, genpd->name);
+ return -EBUSY;
+ }
+
+ return rcar_sysc_power_down(&pd->ch);
+}
+
+static int rcar_sysc_pd_power_on(struct generic_pm_domain *genpd)
+{
+ struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
+
+ pr_debug("%s: %s\n", __func__, genpd->name);
+
+ if (pd->flags & PD_NO_CR) {
+ pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
+ return 0;
+ }
+
+ return rcar_sysc_power_up(&pd->ch);
+}
+
+static bool has_cpg_mstp;
+
+static void __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd)
+{
+ struct generic_pm_domain *genpd = &pd->genpd;
+ const char *name = pd->genpd.name;
+ struct dev_power_governor *gov = &simple_qos_governor;
+
+ if (pd->flags & PD_CPU) {
+ /*
+ * This domain contains a CPU core and therefore it should
+ * only be turned off if the CPU is not in use.
+ */
+ pr_debug("PM domain %s contains %s\n", name, "CPU");
+ pd->flags |= PD_BUSY;
+ gov = &pm_domain_always_on_gov;
+ } else if (pd->flags & PD_SCU) {
+ /*
+ * This domain contains an SCU and cache-controller, and
+ * therefore it should only be turned off if the CPU cores are
+ * not in use.
+ */
+ pr_debug("PM domain %s contains %s\n", name, "SCU");
+ pd->flags |= PD_BUSY;
+ gov = &pm_domain_always_on_gov;
+ } else if (pd->flags & PD_NO_CR) {
+ /*
+ * This domain cannot be turned off.
+ */
+ pd->flags |= PD_BUSY;
+ gov = &pm_domain_always_on_gov;
+ }
+
+ if (!(pd->flags & (PD_CPU | PD_SCU))) {
+ /* Enable Clock Domain for I/O devices */
+ genpd->flags = GENPD_FLAG_PM_CLK;
+ if (has_cpg_mstp) {
+ genpd->attach_dev = cpg_mstp_attach_dev;
+ genpd->detach_dev = cpg_mstp_detach_dev;
+ } else {
+ genpd->attach_dev = cpg_mssr_attach_dev;
+ genpd->detach_dev = cpg_mssr_detach_dev;
+ }
+ }
+
+ genpd->power_off = rcar_sysc_pd_power_off;
+ genpd->power_on = rcar_sysc_pd_power_on;
+
+ if (pd->flags & (PD_CPU | PD_NO_CR)) {
+ /* Skip CPUs (handled by SMP code) and areas without control */
+ pr_debug("%s: Not touching %s\n", __func__, genpd->name);
+ goto finalize;
+ }
+
+ if (!rcar_sysc_power_is_off(&pd->ch)) {
+ pr_debug("%s: %s is already powered\n", __func__, genpd->name);
+ goto finalize;
+ }
+
+ rcar_sysc_power_up(&pd->ch);
+
+finalize:
+ pm_genpd_init(genpd, gov, false);
+}
+
+static const struct of_device_id rcar_sysc_matches[] = {
+#ifdef CONFIG_ARCH_R8A7779
+ { .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7790
+ { .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7791
+ { .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7793
+ /* R-Car M2-N is identical to R-Car M2-W w.r.t. power domains. */
+ { .compatible = "renesas,r8a7793-sysc", .data = &r8a7791_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7794
+ { .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7795
+ { .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_sysc_info },
+#endif
+ { /* sentinel */ }
+};
+
+struct rcar_pm_domains {
+ struct genpd_onecell_data onecell_data;
+ struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
+};
+
+static int __init rcar_sysc_pd_init(void)
+{
+ const struct rcar_sysc_info *info;
+ const struct of_device_id *match;
+ struct rcar_pm_domains *domains;
+ struct device_node *np;
+ u32 syscier, syscimr;
+ void __iomem *base;
+ unsigned int i;
+ int error;
+
+ np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match);
+ if (!np)
+ return -ENODEV;
+
+ info = match->data;
+
+ has_cpg_mstp = of_find_compatible_node(NULL, NULL,
+ "renesas,cpg-mstp-clocks");
+
+ base = of_iomap(np, 0);
+ if (!base) {
+ pr_warn("%s: Cannot map regs\n", np->full_name);
+ error = -ENOMEM;
+ goto out_put;
+ }
+
+ rcar_sysc_base = base;
+
+ domains = kzalloc(sizeof(*domains), GFP_KERNEL);
+ if (!domains) {
+ error = -ENOMEM;
+ goto out_put;
+ }
+
+ domains->onecell_data.domains = domains->domains;
+ domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
+
+ for (i = 0, syscier = 0; i < info->num_areas; i++)
+ syscier |= BIT(info->areas[i].isr_bit);
+
+ /*
+ * Mask all interrupt sources to prevent the CPU from receiving them.
+ * Make sure not to clear reserved bits that were set before.
+ */
+ syscimr = ioread32(base + SYSCIMR);
+ syscimr |= syscier;
+ pr_debug("%s: syscimr = 0x%08x\n", np->full_name, syscimr);
+ iowrite32(syscimr, base + SYSCIMR);
+
+ /*
+ * SYSC needs all interrupt sources enabled to control power.
+ */
+ pr_debug("%s: syscier = 0x%08x\n", np->full_name, syscier);
+ iowrite32(syscier, base + SYSCIER);
+
+ for (i = 0; i < info->num_areas; i++) {
+ const struct rcar_sysc_area *area = &info->areas[i];
+ struct rcar_sysc_pd *pd;
+
+ pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
+ if (!pd) {
+ error = -ENOMEM;
+ goto out_put;
+ }
+
+ strcpy(pd->name, area->name);
+ pd->genpd.name = pd->name;
+ pd->ch.chan_offs = area->chan_offs;
+ pd->ch.chan_bit = area->chan_bit;
+ pd->ch.isr_bit = area->isr_bit;
+ pd->flags = area->flags;
+
+ rcar_sysc_pd_setup(pd);
+ if (area->parent >= 0)
+ pm_genpd_add_subdomain(domains->domains[area->parent],
+ &pd->genpd);
+
+ domains->domains[area->isr_bit] = &pd->genpd;
+ }
+
+ of_genpd_add_provider_onecell(np, &domains->onecell_data);
+
+out_put:
+ of_node_put(np);
+ return error;
+}
+early_initcall(rcar_sysc_pd_init);