diff options
Diffstat (limited to 'kernel/drivers/mailbox/pl320-ipc.c')
| -rw-r--r-- | kernel/drivers/mailbox/pl320-ipc.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/kernel/drivers/mailbox/pl320-ipc.c b/kernel/drivers/mailbox/pl320-ipc.c new file mode 100644 index 000000000..f3755e0aa --- /dev/null +++ b/kernel/drivers/mailbox/pl320-ipc.c @@ -0,0 +1,198 @@ +/* + * Copyright 2012 Calxeda, Inc. + * + * 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. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/types.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/interrupt.h> +#include <linux/completion.h> +#include <linux/mutex.h> +#include <linux/notifier.h> +#include <linux/spinlock.h> +#include <linux/device.h> +#include <linux/amba/bus.h> + +#include <linux/pl320-ipc.h> + +#define IPCMxSOURCE(m) ((m) * 0x40) +#define IPCMxDSET(m) (((m) * 0x40) + 0x004) +#define IPCMxDCLEAR(m) (((m) * 0x40) + 0x008) +#define IPCMxDSTATUS(m) (((m) * 0x40) + 0x00C) +#define IPCMxMODE(m) (((m) * 0x40) + 0x010) +#define IPCMxMSET(m) (((m) * 0x40) + 0x014) +#define IPCMxMCLEAR(m) (((m) * 0x40) + 0x018) +#define IPCMxMSTATUS(m) (((m) * 0x40) + 0x01C) +#define IPCMxSEND(m) (((m) * 0x40) + 0x020) +#define IPCMxDR(m, dr) (((m) * 0x40) + ((dr) * 4) + 0x024) + +#define IPCMMIS(irq) (((irq) * 8) + 0x800) +#define IPCMRIS(irq) (((irq) * 8) + 0x804) + +#define MBOX_MASK(n) (1 << (n)) +#define IPC_TX_MBOX 1 +#define IPC_RX_MBOX 2 + +#define CHAN_MASK(n) (1 << (n)) +#define A9_SOURCE 1 +#define M3_SOURCE 0 + +static void __iomem *ipc_base; +static int ipc_irq; +static DEFINE_MUTEX(ipc_m1_lock); +static DECLARE_COMPLETION(ipc_completion); +static ATOMIC_NOTIFIER_HEAD(ipc_notifier); + +static inline void set_destination(int source, int mbox) +{ + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDSET(mbox)); + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMSET(mbox)); +} + +static inline void clear_destination(int source, int mbox) +{ + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDCLEAR(mbox)); + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMCLEAR(mbox)); +} + +static void __ipc_send(int mbox, u32 *data) +{ + int i; + for (i = 0; i < 7; i++) + __raw_writel(data[i], ipc_base + IPCMxDR(mbox, i)); + __raw_writel(0x1, ipc_base + IPCMxSEND(mbox)); +} + +static u32 __ipc_rcv(int mbox, u32 *data) +{ + int i; + for (i = 0; i < 7; i++) + data[i] = __raw_readl(ipc_base + IPCMxDR(mbox, i)); + return data[1]; +} + +/* blocking implmentation from the A9 side, not usuable in interrupts! */ +int pl320_ipc_transmit(u32 *data) +{ + int ret; + + mutex_lock(&ipc_m1_lock); + + init_completion(&ipc_completion); + __ipc_send(IPC_TX_MBOX, data); + ret = wait_for_completion_timeout(&ipc_completion, + msecs_to_jiffies(1000)); + if (ret == 0) { + ret = -ETIMEDOUT; + goto out; + } + + ret = __ipc_rcv(IPC_TX_MBOX, data); +out: + mutex_unlock(&ipc_m1_lock); + return ret; +} +EXPORT_SYMBOL_GPL(pl320_ipc_transmit); + +static irqreturn_t ipc_handler(int irq, void *dev) +{ + u32 irq_stat; + u32 data[7]; + + irq_stat = __raw_readl(ipc_base + IPCMMIS(1)); + if (irq_stat & MBOX_MASK(IPC_TX_MBOX)) { + __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX)); + complete(&ipc_completion); + } + if (irq_stat & MBOX_MASK(IPC_RX_MBOX)) { + __ipc_rcv(IPC_RX_MBOX, data); + atomic_notifier_call_chain(&ipc_notifier, data[0], data + 1); + __raw_writel(2, ipc_base + IPCMxSEND(IPC_RX_MBOX)); + } + + return IRQ_HANDLED; +} + +int pl320_ipc_register_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_register(&ipc_notifier, nb); +} +EXPORT_SYMBOL_GPL(pl320_ipc_register_notifier); + +int pl320_ipc_unregister_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(&ipc_notifier, nb); +} +EXPORT_SYMBOL_GPL(pl320_ipc_unregister_notifier); + +static int pl320_probe(struct amba_device *adev, const struct amba_id *id) +{ + int ret; + + ipc_base = ioremap(adev->res.start, resource_size(&adev->res)); + if (ipc_base == NULL) + return -ENOMEM; + + __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX)); + + ipc_irq = adev->irq[0]; + ret = request_irq(ipc_irq, ipc_handler, 0, dev_name(&adev->dev), NULL); + if (ret < 0) + goto err; + + /* Init slow mailbox */ + __raw_writel(CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxSOURCE(IPC_TX_MBOX)); + __raw_writel(CHAN_MASK(M3_SOURCE), + ipc_base + IPCMxDSET(IPC_TX_MBOX)); + __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxMSET(IPC_TX_MBOX)); + + /* Init receive mailbox */ + __raw_writel(CHAN_MASK(M3_SOURCE), + ipc_base + IPCMxSOURCE(IPC_RX_MBOX)); + __raw_writel(CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxDSET(IPC_RX_MBOX)); + __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxMSET(IPC_RX_MBOX)); + + return 0; +err: + iounmap(ipc_base); + return ret; +} + +static struct amba_id pl320_ids[] = { + { + .id = 0x00041320, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; + +static struct amba_driver pl320_driver = { + .drv = { + .name = "pl320", + }, + .id_table = pl320_ids, + .probe = pl320_probe, +}; + +static int __init ipc_init(void) +{ + return amba_driver_register(&pl320_driver); +} +module_init(ipc_init); |