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path: root/drivers/pmdomain/renesas/rcar-gen4-sysc.c
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Diffstat (limited to 'drivers/pmdomain/renesas/rcar-gen4-sysc.c')
-rw-r--r--drivers/pmdomain/renesas/rcar-gen4-sysc.c379
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/pmdomain/renesas/rcar-gen4-sysc.c b/drivers/pmdomain/renesas/rcar-gen4-sysc.c
new file mode 100644
index 000000000000..9e5e6e077abc
--- /dev/null
+++ b/drivers/pmdomain/renesas/rcar-gen4-sysc.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * R-Car Gen4 SYSC Power management support
+ *
+ * Copyright (C) 2021 Renesas Electronics Corp.
+ */
+
+#include <linux/bits.h>
+#include <linux/clk/renesas.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.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/types.h>
+
+#include "rcar-gen4-sysc.h"
+
+/* SYSC Common */
+#define SYSCSR 0x000 /* SYSC Status Register */
+#define SYSCPONSR(x) (0x800 + ((x) * 0x4)) /* Power-ON Status Register 0 */
+#define SYSCPOFFSR(x) (0x808 + ((x) * 0x4)) /* Power-OFF Status Register */
+#define SYSCISCR(x) (0x810 + ((x) * 0x4)) /* Interrupt Status/Clear Register */
+#define SYSCIER(x) (0x820 + ((x) * 0x4)) /* Interrupt Enable Register */
+#define SYSCIMR(x) (0x830 + ((x) * 0x4)) /* Interrupt Mask Register */
+
+/* Power Domain Registers */
+#define PDRSR(n) (0x1000 + ((n) * 0x40))
+#define PDRONCR(n) (0x1004 + ((n) * 0x40))
+#define PDROFFCR(n) (0x1008 + ((n) * 0x40))
+#define PDRESR(n) (0x100C + ((n) * 0x40))
+
+/* PWRON/PWROFF */
+#define PWRON_PWROFF BIT(0) /* Power-ON/OFF request */
+
+/* PDRESR */
+#define PDRESR_ERR BIT(0)
+
+/* PDRSR */
+#define PDRSR_OFF BIT(0) /* Power-OFF state */
+#define PDRSR_ON BIT(4) /* Power-ON state */
+#define PDRSR_OFF_STATE BIT(8) /* Processing Power-OFF sequence */
+#define PDRSR_ON_STATE BIT(12) /* Processing Power-ON sequence */
+
+#define SYSCSR_BUSY GENMASK(1, 0) /* All bit sets is not busy */
+
+#define SYSCSR_TIMEOUT 10000
+#define SYSCSR_DELAY_US 10
+
+#define PDRESR_RETRIES 1000
+#define PDRESR_DELAY_US 10
+
+#define SYSCISR_TIMEOUT 10000
+#define SYSCISR_DELAY_US 10
+
+#define RCAR_GEN4_PD_ALWAYS_ON 64
+#define NUM_DOMAINS_EACH_REG BITS_PER_TYPE(u32)
+
+static void __iomem *rcar_gen4_sysc_base;
+static DEFINE_SPINLOCK(rcar_gen4_sysc_lock); /* SMP CPUs + I/O devices */
+
+static int rcar_gen4_sysc_pwr_on_off(u8 pdr, bool on)
+{
+ unsigned int reg_offs;
+ u32 val;
+ int ret;
+
+ if (on)
+ reg_offs = PDRONCR(pdr);
+ else
+ reg_offs = PDROFFCR(pdr);
+
+ /* Wait until SYSC is ready to accept a power request */
+ ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCSR, val,
+ (val & SYSCSR_BUSY) == SYSCSR_BUSY,
+ SYSCSR_DELAY_US, SYSCSR_TIMEOUT);
+ if (ret < 0)
+ return -EAGAIN;
+
+ /* Submit power shutoff or power resume request */
+ iowrite32(PWRON_PWROFF, rcar_gen4_sysc_base + reg_offs);
+
+ return 0;
+}
+
+static int clear_irq_flags(unsigned int reg_idx, unsigned int isr_mask)
+{
+ u32 val;
+ int ret;
+
+ iowrite32(isr_mask, rcar_gen4_sysc_base + SYSCISCR(reg_idx));
+
+ ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx),
+ val, !(val & isr_mask),
+ SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
+ if (ret < 0) {
+ pr_err("\n %s : Can not clear IRQ flags in SYSCISCR", __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int rcar_gen4_sysc_power(u8 pdr, bool on)
+{
+ unsigned int isr_mask;
+ unsigned int reg_idx, bit_idx;
+ unsigned int status;
+ unsigned long flags;
+ int ret = 0;
+ u32 val;
+ int k;
+
+ spin_lock_irqsave(&rcar_gen4_sysc_lock, flags);
+
+ reg_idx = pdr / NUM_DOMAINS_EACH_REG;
+ bit_idx = pdr % NUM_DOMAINS_EACH_REG;
+
+ isr_mask = BIT(bit_idx);
+
+ /*
+ * The interrupt source needs to be enabled, but masked, to prevent the
+ * CPU from receiving it.
+ */
+ iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIER(reg_idx)) | isr_mask,
+ rcar_gen4_sysc_base + SYSCIER(reg_idx));
+ iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIMR(reg_idx)) | isr_mask,
+ rcar_gen4_sysc_base + SYSCIMR(reg_idx));
+
+ ret = clear_irq_flags(reg_idx, isr_mask);
+ if (ret)
+ goto out;
+
+ /* Submit power shutoff or resume request until it was accepted */
+ for (k = 0; k < PDRESR_RETRIES; k++) {
+ ret = rcar_gen4_sysc_pwr_on_off(pdr, on);
+ if (ret)
+ goto out;
+
+ status = ioread32(rcar_gen4_sysc_base + PDRESR(pdr));
+ if (!(status & PDRESR_ERR))
+ break;
+
+ udelay(PDRESR_DELAY_US);
+ }
+
+ if (k == PDRESR_RETRIES) {
+ ret = -EIO;
+ goto out;
+ }
+
+ /* Wait until the power shutoff or resume request has completed * */
+ ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx),
+ val, (val & isr_mask),
+ SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
+ if (ret < 0) {
+ ret = -EIO;
+ goto out;
+ }
+
+ /* Clear interrupt flags */
+ ret = clear_irq_flags(reg_idx, isr_mask);
+ if (ret)
+ goto out;
+
+ out:
+ spin_unlock_irqrestore(&rcar_gen4_sysc_lock, flags);
+
+ pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
+ pdr, ioread32(rcar_gen4_sysc_base + SYSCISCR(reg_idx)), ret);
+ return ret;
+}
+
+static bool rcar_gen4_sysc_power_is_off(u8 pdr)
+{
+ unsigned int st;
+
+ st = ioread32(rcar_gen4_sysc_base + PDRSR(pdr));
+
+ if (st & PDRSR_OFF)
+ return true;
+
+ return false;
+}
+
+struct rcar_gen4_sysc_pd {
+ struct generic_pm_domain genpd;
+ u8 pdr;
+ unsigned int flags;
+ char name[];
+};
+
+static inline struct rcar_gen4_sysc_pd *to_rcar_gen4_pd(struct generic_pm_domain *d)
+{
+ return container_of(d, struct rcar_gen4_sysc_pd, genpd);
+}
+
+static int rcar_gen4_sysc_pd_power_off(struct generic_pm_domain *genpd)
+{
+ struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd);
+
+ pr_debug("%s: %s\n", __func__, genpd->name);
+ return rcar_gen4_sysc_power(pd->pdr, false);
+}
+
+static int rcar_gen4_sysc_pd_power_on(struct generic_pm_domain *genpd)
+{
+ struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd);
+
+ pr_debug("%s: %s\n", __func__, genpd->name);
+ return rcar_gen4_sysc_power(pd->pdr, true);
+}
+
+static int __init rcar_gen4_sysc_pd_setup(struct rcar_gen4_sysc_pd *pd)
+{
+ struct generic_pm_domain *genpd = &pd->genpd;
+ const char *name = pd->genpd.name;
+ int error;
+
+ 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");
+ genpd->flags |= GENPD_FLAG_ALWAYS_ON;
+ } 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");
+ genpd->flags |= GENPD_FLAG_ALWAYS_ON;
+ } else if (pd->flags & PD_NO_CR) {
+ /*
+ * This domain cannot be turned off.
+ */
+ genpd->flags |= GENPD_FLAG_ALWAYS_ON;
+ }
+
+ if (!(pd->flags & (PD_CPU | PD_SCU))) {
+ /* Enable Clock Domain for I/O devices */
+ genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
+ genpd->attach_dev = cpg_mssr_attach_dev;
+ genpd->detach_dev = cpg_mssr_detach_dev;
+ }
+
+ genpd->power_off = rcar_gen4_sysc_pd_power_off;
+ genpd->power_on = rcar_gen4_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_gen4_sysc_power_is_off(pd->pdr)) {
+ pr_debug("%s: %s is already powered\n", __func__, genpd->name);
+ goto finalize;
+ }
+
+ rcar_gen4_sysc_power(pd->pdr, true);
+
+finalize:
+ error = pm_genpd_init(genpd, &simple_qos_governor, false);
+ if (error)
+ pr_err("Failed to init PM domain %s: %d\n", name, error);
+
+ return error;
+}
+
+static const struct of_device_id rcar_gen4_sysc_matches[] __initconst = {
+#ifdef CONFIG_SYSC_R8A779A0
+ { .compatible = "renesas,r8a779a0-sysc", .data = &r8a779a0_sysc_info },
+#endif
+#ifdef CONFIG_SYSC_R8A779F0
+ { .compatible = "renesas,r8a779f0-sysc", .data = &r8a779f0_sysc_info },
+#endif
+#ifdef CONFIG_SYSC_R8A779G0
+ { .compatible = "renesas,r8a779g0-sysc", .data = &r8a779g0_sysc_info },
+#endif
+ { /* sentinel */ }
+};
+
+struct rcar_gen4_pm_domains {
+ struct genpd_onecell_data onecell_data;
+ struct generic_pm_domain *domains[RCAR_GEN4_PD_ALWAYS_ON + 1];
+};
+
+static struct genpd_onecell_data *rcar_gen4_sysc_onecell_data;
+
+static int __init rcar_gen4_sysc_pd_init(void)
+{
+ const struct rcar_gen4_sysc_info *info;
+ const struct of_device_id *match;
+ struct rcar_gen4_pm_domains *domains;
+ struct device_node *np;
+ void __iomem *base;
+ unsigned int i;
+ int error;
+
+ np = of_find_matching_node_and_match(NULL, rcar_gen4_sysc_matches, &match);
+ if (!np)
+ return -ENODEV;
+
+ info = match->data;
+
+ base = of_iomap(np, 0);
+ if (!base) {
+ pr_warn("%pOF: Cannot map regs\n", np);
+ error = -ENOMEM;
+ goto out_put;
+ }
+
+ rcar_gen4_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);
+ rcar_gen4_sysc_onecell_data = &domains->onecell_data;
+
+ for (i = 0; i < info->num_areas; i++) {
+ const struct rcar_gen4_sysc_area *area = &info->areas[i];
+ struct rcar_gen4_sysc_pd *pd;
+ size_t n;
+
+ if (!area->name) {
+ /* Skip NULLified area */
+ continue;
+ }
+
+ n = strlen(area->name) + 1;
+ pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
+ if (!pd) {
+ error = -ENOMEM;
+ goto out_put;
+ }
+
+ memcpy(pd->name, area->name, n);
+ pd->genpd.name = pd->name;
+ pd->pdr = area->pdr;
+ pd->flags = area->flags;
+
+ error = rcar_gen4_sysc_pd_setup(pd);
+ if (error)
+ goto out_put;
+
+ domains->domains[area->pdr] = &pd->genpd;
+
+ if (area->parent < 0)
+ continue;
+
+ error = pm_genpd_add_subdomain(domains->domains[area->parent],
+ &pd->genpd);
+ if (error) {
+ pr_warn("Failed to add PM subdomain %s to parent %u\n",
+ area->name, area->parent);
+ goto out_put;
+ }
+ }
+
+ error = of_genpd_add_provider_onecell(np, &domains->onecell_data);
+
+out_put:
+ of_node_put(np);
+ return error;
+}
+early_initcall(rcar_gen4_sysc_pd_init);