1 files changed, 479 insertions, 0 deletions

diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
new file mode 100644
index 000000000000..0cde356c11ab
--- /dev/null
+++ b/drivers/mailbox/tegra-hsp.c
@@ -0,0 +1,479 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/mailbox/tegra186-hsp.h>
+
+#define HSP_INT_DIMENSIONING    0x380
+#define HSP_nSM_SHIFT           0
+#define HSP_nSS_SHIFT           4
+#define HSP_nAS_SHIFT           8
+#define HSP_nDB_SHIFT           12
+#define HSP_nSI_SHIFT           16
+#define HSP_nINT_MASK           0xf
+
+#define HSP_DB_TRIGGER  0x0
+#define HSP_DB_ENABLE   0x4
+#define HSP_DB_RAW      0x8
+#define HSP_DB_PENDING  0xc
+
+#define HSP_DB_CCPLEX           1
+#define HSP_DB_BPMP             3
+#define HSP_DB_MAX              7
+
+struct tegra_hsp_channel;
+struct tegra_hsp;
+
+struct tegra_hsp_channel {
+        struct tegra_hsp *hsp;
+        struct mbox_chan *chan;
+        void __iomem *regs;
+};
+
+struct tegra_hsp_doorbell {
+        struct tegra_hsp_channel channel;
+        struct list_head list;
+        const char *name;
+        unsigned int master;
+        unsigned int index;
+};
+
+struct tegra_hsp_db_map {
+        const char *name;
+        unsigned int master;
+        unsigned int index;
+};
+
+struct tegra_hsp_soc {
+        const struct tegra_hsp_db_map *map;
+};
+
+struct tegra_hsp {
+        const struct tegra_hsp_soc *soc;
+        struct mbox_controller mbox;
+        void __iomem *regs;
+        unsigned int irq;
+        unsigned int num_sm;
+        unsigned int num_as;
+        unsigned int num_ss;
+        unsigned int num_db;
+        unsigned int num_si;
+        spinlock_t lock;
+
+        struct list_head doorbells;
+};
+
+static inline struct tegra_hsp *
+to_tegra_hsp(struct mbox_controller *mbox)
+{
+        return container_of(mbox, struct tegra_hsp, mbox);
+}
+
+static inline u32 tegra_hsp_readl(struct tegra_hsp *hsp, unsigned int offset)
+{
+        return readl(hsp->regs + offset);
+}
+
+static inline void tegra_hsp_writel(struct tegra_hsp *hsp, u32 value,
+                                    unsigned int offset)
+{
+        writel(value, hsp->regs + offset);
+}
+
+static inline u32 tegra_hsp_channel_readl(struct tegra_hsp_channel *channel,
+                                          unsigned int offset)
+{
+        return readl(channel->regs + offset);
+}
+
+static inline void tegra_hsp_channel_writel(struct tegra_hsp_channel *channel,
+                                            u32 value, unsigned int offset)
+{
+        writel(value, channel->regs + offset);
+}
+
+static bool tegra_hsp_doorbell_can_ring(struct tegra_hsp_doorbell *db)
+{
+        u32 value;
+
+        value = tegra_hsp_channel_readl(&db->channel, HSP_DB_ENABLE);
+
+        return (value & BIT(TEGRA_HSP_DB_MASTER_CCPLEX)) != 0;
+}
+
+static struct tegra_hsp_doorbell *
+__tegra_hsp_doorbell_get(struct tegra_hsp *hsp, unsigned int master)
+{
+        struct tegra_hsp_doorbell *entry;
+
+        list_for_each_entry(entry, &hsp->doorbells, list)
+                if (entry->master == master)
+                        return entry;
+
+        return NULL;
+}
+
+static struct tegra_hsp_doorbell *
+tegra_hsp_doorbell_get(struct tegra_hsp *hsp, unsigned int master)
+{
+        struct tegra_hsp_doorbell *db;
+        unsigned long flags;
+
+        spin_lock_irqsave(&hsp->lock, flags);
+        db = __tegra_hsp_doorbell_get(hsp, master);
+        spin_unlock_irqrestore(&hsp->lock, flags);
+
+        return db;
+}
+
+static irqreturn_t tegra_hsp_doorbell_irq(int irq, void *data)
+{
+        struct tegra_hsp *hsp = data;
+        struct tegra_hsp_doorbell *db;
+        unsigned long master, value;
+
+        db = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+        if (!db)
+                return IRQ_NONE;
+
+        value = tegra_hsp_channel_readl(&db->channel, HSP_DB_PENDING);
+        tegra_hsp_channel_writel(&db->channel, value, HSP_DB_PENDING);
+
+        spin_lock(&hsp->lock);
+
+        for_each_set_bit(master, &value, hsp->mbox.num_chans) {
+                struct tegra_hsp_doorbell *db;
+
+                db = __tegra_hsp_doorbell_get(hsp, master);
+                /*
+                 * Depending on the bootloader chain, the CCPLEX doorbell will
+                 * have some doorbells enabled, which means that requesting an
+                 * interrupt will immediately fire.
+                 *
+                 * In that case, db->channel.chan will still be NULL here and
+                 * cause a crash if not properly guarded.
+                 *
+                 * It remains to be seen if ignoring the doorbell in that case
+                 * is the correct solution.
+                 */
+                if (db && db->channel.chan)
+                        mbox_chan_received_data(db->channel.chan, NULL);
+        }
+
+        spin_unlock(&hsp->lock);
+
+        return IRQ_HANDLED;
+}
+
+static struct tegra_hsp_channel *
+tegra_hsp_doorbell_create(struct tegra_hsp *hsp, const char *name,
+                          unsigned int master, unsigned int index)
+{
+        struct tegra_hsp_doorbell *db;
+        unsigned int offset;
+        unsigned long flags;
+
+        db = kzalloc(sizeof(*db), GFP_KERNEL);
+        if (!db)
+                return ERR_PTR(-ENOMEM);
+
+        offset = (1 + (hsp->num_sm / 2) + hsp->num_ss + hsp->num_as) << 16;
+        offset += index * 0x100;
+
+        db->channel.regs = hsp->regs + offset;
+        db->channel.hsp = hsp;
+
+        db->name = kstrdup_const(name, GFP_KERNEL);
+        db->master = master;
+        db->index = index;
+
+        spin_lock_irqsave(&hsp->lock, flags);
+        list_add_tail(&db->list, &hsp->doorbells);
+        spin_unlock_irqrestore(&hsp->lock, flags);
+
+        return &db->channel;
+}
+
+static void __tegra_hsp_doorbell_destroy(struct tegra_hsp_doorbell *db)
+{
+        list_del(&db->list);
+        kfree_const(db->name);
+        kfree(db);
+}
+
+static int tegra_hsp_doorbell_send_data(struct mbox_chan *chan, void *data)
+{
+        struct tegra_hsp_doorbell *db = chan->con_priv;
+
+        tegra_hsp_channel_writel(&db->channel, 1, HSP_DB_TRIGGER);
+
+        return 0;
+}
+
+static int tegra_hsp_doorbell_startup(struct mbox_chan *chan)
+{
+        struct tegra_hsp_doorbell *db = chan->con_priv;
+        struct tegra_hsp *hsp = db->channel.hsp;
+        struct tegra_hsp_doorbell *ccplex;
+        unsigned long flags;
+        u32 value;
+
+        if (db->master >= hsp->mbox.num_chans) {
+                dev_err(hsp->mbox.dev,
+                        "invalid master ID %u for HSP channel\n",
+                        db->master);
+                return -EINVAL;
+        }
+
+        ccplex = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+        if (!ccplex)
+                return -ENODEV;
+
+        if (!tegra_hsp_doorbell_can_ring(db))
+                return -ENODEV;
+
+        spin_lock_irqsave(&hsp->lock, flags);
+
+        value = tegra_hsp_channel_readl(&ccplex->channel, HSP_DB_ENABLE);
+        value |= BIT(db->master);
+        tegra_hsp_channel_writel(&ccplex->channel, value, HSP_DB_ENABLE);
+
+        spin_unlock_irqrestore(&hsp->lock, flags);
+
+        return 0;
+}
+
+static void tegra_hsp_doorbell_shutdown(struct mbox_chan *chan)
+{
+        struct tegra_hsp_doorbell *db = chan->con_priv;
+        struct tegra_hsp *hsp = db->channel.hsp;
+        struct tegra_hsp_doorbell *ccplex;
+        unsigned long flags;
+        u32 value;
+
+        ccplex = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+        if (!ccplex)
+                return;
+
+        spin_lock_irqsave(&hsp->lock, flags);
+
+        value = tegra_hsp_channel_readl(&ccplex->channel, HSP_DB_ENABLE);
+        value &= ~BIT(db->master);
+        tegra_hsp_channel_writel(&ccplex->channel, value, HSP_DB_ENABLE);
+
+        spin_unlock_irqrestore(&hsp->lock, flags);
+}
+
+static const struct mbox_chan_ops tegra_hsp_doorbell_ops = {
+        .send_data = tegra_hsp_doorbell_send_data,
+        .startup = tegra_hsp_doorbell_startup,
+        .shutdown = tegra_hsp_doorbell_shutdown,
+};
+
+static struct mbox_chan *of_tegra_hsp_xlate(struct mbox_controller *mbox,
+                                            const struct of_phandle_args *args)
+{
+        struct tegra_hsp_channel *channel = ERR_PTR(-ENODEV);
+        struct tegra_hsp *hsp = to_tegra_hsp(mbox);
+        unsigned int type = args->args[0];
+        unsigned int master = args->args[1];
+        struct tegra_hsp_doorbell *db;
+        struct mbox_chan *chan;
+        unsigned long flags;
+        unsigned int i;
+
+        switch (type) {
+        case TEGRA_HSP_MBOX_TYPE_DB:
+                db = tegra_hsp_doorbell_get(hsp, master);
+                if (db)
+                        channel = &db->channel;
+
+                break;
+
+        default:
+                break;
+        }
+
+        if (IS_ERR(channel))
+                return ERR_CAST(channel);
+
+        spin_lock_irqsave(&hsp->lock, flags);
+
+        for (i = 0; i < hsp->mbox.num_chans; i++) {
+                chan = &hsp->mbox.chans[i];
+                if (!chan->con_priv) {
+                        chan->con_priv = channel;
+                        channel->chan = chan;
+                        break;
+                }
+
+                chan = NULL;
+        }
+
+        spin_unlock_irqrestore(&hsp->lock, flags);
+
+        return chan ?: ERR_PTR(-EBUSY);
+}
+
+static void tegra_hsp_remove_doorbells(struct tegra_hsp *hsp)
+{
+        struct tegra_hsp_doorbell *db, *tmp;
+        unsigned long flags;
+
+        spin_lock_irqsave(&hsp->lock, flags);
+
+        list_for_each_entry_safe(db, tmp, &hsp->doorbells, list)
+                __tegra_hsp_doorbell_destroy(db);
+
+        spin_unlock_irqrestore(&hsp->lock, flags);
+}
+
+static int tegra_hsp_add_doorbells(struct tegra_hsp *hsp)
+{
+        const struct tegra_hsp_db_map *map = hsp->soc->map;
+        struct tegra_hsp_channel *channel;
+
+        while (map->name) {
+                channel = tegra_hsp_doorbell_create(hsp, map->name,
+                                                    map->master, map->index);
+                if (IS_ERR(channel)) {
+                        tegra_hsp_remove_doorbells(hsp);
+                        return PTR_ERR(channel);
+                }
+
+                map++;
+        }
+
+        return 0;
+}
+
+static int tegra_hsp_probe(struct platform_device *pdev)
+{
+        struct tegra_hsp *hsp;
+        struct resource *res;
+        u32 value;
+        int err;
+
+        hsp = devm_kzalloc(&pdev->dev, sizeof(*hsp), GFP_KERNEL);
+        if (!hsp)
+                return -ENOMEM;
+
+        hsp->soc = of_device_get_match_data(&pdev->dev);
+        INIT_LIST_HEAD(&hsp->doorbells);
+        spin_lock_init(&hsp->lock);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        hsp->regs = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(hsp->regs))
+                return PTR_ERR(hsp->regs);
+
+        value = tegra_hsp_readl(hsp, HSP_INT_DIMENSIONING);
+        hsp->num_sm = (value >> HSP_nSM_SHIFT) & HSP_nINT_MASK;
+        hsp->num_ss = (value >> HSP_nSS_SHIFT) & HSP_nINT_MASK;
+        hsp->num_as = (value >> HSP_nAS_SHIFT) & HSP_nINT_MASK;
+        hsp->num_db = (value >> HSP_nDB_SHIFT) & HSP_nINT_MASK;
+        hsp->num_si = (value >> HSP_nSI_SHIFT) & HSP_nINT_MASK;
+
+        err = platform_get_irq_byname(pdev, "doorbell");
+        if (err < 0) {
+                dev_err(&pdev->dev, "failed to get doorbell IRQ: %d\n", err);
+                return err;
+        }
+
+        hsp->irq = err;
+
+        hsp->mbox.of_xlate = of_tegra_hsp_xlate;
+        hsp->mbox.num_chans = 32;
+        hsp->mbox.dev = &pdev->dev;
+        hsp->mbox.txdone_irq = false;
+        hsp->mbox.txdone_poll = false;
+        hsp->mbox.ops = &tegra_hsp_doorbell_ops;
+
+        hsp->mbox.chans = devm_kcalloc(&pdev->dev, hsp->mbox.num_chans,
+                                        sizeof(*hsp->mbox.chans),
+                                        GFP_KERNEL);
+        if (!hsp->mbox.chans)
+                return -ENOMEM;
+
+        err = tegra_hsp_add_doorbells(hsp);
+        if (err < 0) {
+                dev_err(&pdev->dev, "failed to add doorbells: %d\n", err);
+                return err;
+        }
+
+        platform_set_drvdata(pdev, hsp);
+
+        err = mbox_controller_register(&hsp->mbox);
+        if (err) {
+                dev_err(&pdev->dev, "failed to register mailbox: %d\n", err);
+                tegra_hsp_remove_doorbells(hsp);
+                return err;
+        }
+
+        err = devm_request_irq(&pdev->dev, hsp->irq, tegra_hsp_doorbell_irq,
+                               IRQF_NO_SUSPEND, dev_name(&pdev->dev), hsp);
+        if (err < 0) {
+                dev_err(&pdev->dev, "failed to request IRQ#%u: %d\n",
+                        hsp->irq, err);
+                return err;
+        }
+
+        return 0;
+}
+
+static int tegra_hsp_remove(struct platform_device *pdev)
+{
+        struct tegra_hsp *hsp = platform_get_drvdata(pdev);
+
+        mbox_controller_unregister(&hsp->mbox);
+        tegra_hsp_remove_doorbells(hsp);
+
+        return 0;
+}
+
+static const struct tegra_hsp_db_map tegra186_hsp_db_map[] = {
+        { "ccplex", TEGRA_HSP_DB_MASTER_CCPLEX, HSP_DB_CCPLEX, },
+        { "bpmp",   TEGRA_HSP_DB_MASTER_BPMP,   HSP_DB_BPMP,   },
+        { /* sentinel */ }
+};
+
+static const struct tegra_hsp_soc tegra186_hsp_soc = {
+        .map = tegra186_hsp_db_map,
+};
+
+static const struct of_device_id tegra_hsp_match[] = {
+        { .compatible = "nvidia,tegra186-hsp", .data = &tegra186_hsp_soc },
+        { }
+};
+
+static struct platform_driver tegra_hsp_driver = {
+        .driver = {
+                .name = "tegra-hsp",
+                .of_match_table = tegra_hsp_match,
+        },
+        .probe = tegra_hsp_probe,
+        .remove = tegra_hsp_remove,
+};
+
+static int __init tegra_hsp_init(void)
+{
+        return platform_driver_register(&tegra_hsp_driver);
+}
+core_initcall(tegra_hsp_init);