diff options
Diffstat (limited to 'arch/arm/mach-msm/proc_comm.c')
| -rw-r--r-- | arch/arm/mach-msm/proc_comm.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/arch/arm/mach-msm/proc_comm.c b/arch/arm/mach-msm/proc_comm.c new file mode 100644 index 000000000000..915ee704ed3c --- /dev/null +++ b/arch/arm/mach-msm/proc_comm.c @@ -0,0 +1,110 @@ +/* arch/arm/mach-msm/proc_comm.c + * + * Copyright (C) 2007-2008 Google, Inc. + * Author: Brian Swetland <swetland@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that 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/delay.h> +#include <linux/errno.h> +#include <linux/io.h> +#include <linux/spinlock.h> +#include <mach/msm_iomap.h> +#include <mach/system.h> + +#include "proc_comm.h" + +#define MSM_A2M_INT(n) (MSM_CSR_BASE + 0x400 + (n) * 4) + +static inline void notify_other_proc_comm(void) +{ + writel(1, MSM_A2M_INT(6)); +} + +#define APP_COMMAND 0x00 +#define APP_STATUS 0x04 +#define APP_DATA1 0x08 +#define APP_DATA2 0x0C + +#define MDM_COMMAND 0x10 +#define MDM_STATUS 0x14 +#define MDM_DATA1 0x18 +#define MDM_DATA2 0x1C + +static DEFINE_SPINLOCK(proc_comm_lock); + +/* The higher level SMD support will install this to + * provide a way to check for and handle modem restart. + */ +int (*msm_check_for_modem_crash)(void); + +/* Poll for a state change, checking for possible + * modem crashes along the way (so we don't wait + * forever while the ARM9 is blowing up). + * + * Return an error in the event of a modem crash and + * restart so the msm_proc_comm() routine can restart + * the operation from the beginning. + */ +static int proc_comm_wait_for(void __iomem *addr, unsigned value) +{ + for (;;) { + if (readl(addr) == value) + return 0; + + if (msm_check_for_modem_crash) + if (msm_check_for_modem_crash()) + return -EAGAIN; + } +} + +int msm_proc_comm(unsigned cmd, unsigned *data1, unsigned *data2) +{ + void __iomem *base = MSM_SHARED_RAM_BASE; + unsigned long flags; + int ret; + + spin_lock_irqsave(&proc_comm_lock, flags); + + for (;;) { + if (proc_comm_wait_for(base + MDM_STATUS, PCOM_READY)) + continue; + + writel(cmd, base + APP_COMMAND); + writel(data1 ? *data1 : 0, base + APP_DATA1); + writel(data2 ? *data2 : 0, base + APP_DATA2); + + notify_other_proc_comm(); + + if (proc_comm_wait_for(base + APP_COMMAND, PCOM_CMD_DONE)) + continue; + + if (readl(base + APP_STATUS) != PCOM_CMD_FAIL) { + if (data1) + *data1 = readl(base + APP_DATA1); + if (data2) + *data2 = readl(base + APP_DATA2); + ret = 0; + } else { + ret = -EIO; + } + break; + } + + writel(PCOM_CMD_IDLE, base + APP_COMMAND); + + spin_unlock_irqrestore(&proc_comm_lock, flags); + + return ret; +} + + |