diff options
Diffstat (limited to 'drivers/remoteproc/mtk_scp_ipi.c')
| -rw-r--r-- | drivers/remoteproc/mtk_scp_ipi.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/remoteproc/mtk_scp_ipi.c b/drivers/remoteproc/mtk_scp_ipi.c new file mode 100644 index 000000000000..3d3d87210ef2 --- /dev/null +++ b/drivers/remoteproc/mtk_scp_ipi.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Copyright (c) 2019 MediaTek Inc. + +#include <asm/barrier.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/remoteproc/mtk_scp.h> + +#include "mtk_common.h" + +/** + * scp_ipi_register() - register an ipi function + * + * @scp: mtk_scp structure + * @id: IPI ID + * @handler: IPI handler + * @priv: private data for IPI handler + * + * Register an ipi function to receive ipi interrupt from SCP. + * + * Returns 0 if ipi registers successfully, -error on error. + */ +int scp_ipi_register(struct mtk_scp *scp, + u32 id, + scp_ipi_handler_t handler, + void *priv) +{ + if (!scp) { + dev_err(scp->dev, "scp device is not ready\n"); + return -EPROBE_DEFER; + } + + if (WARN_ON(id >= SCP_IPI_MAX) || WARN_ON(handler == NULL)) + return -EINVAL; + + scp_ipi_lock(scp, id); + scp->ipi_desc[id].handler = handler; + scp->ipi_desc[id].priv = priv; + scp_ipi_unlock(scp, id); + + return 0; +} +EXPORT_SYMBOL_GPL(scp_ipi_register); + +/** + * scp_ipi_unregister() - unregister an ipi function + * + * @scp: mtk_scp structure + * @id: IPI ID + * + * Unregister an ipi function to receive ipi interrupt from SCP. + */ +void scp_ipi_unregister(struct mtk_scp *scp, u32 id) +{ + if (!scp) + return; + + if (WARN_ON(id >= SCP_IPI_MAX)) + return; + + scp_ipi_lock(scp, id); + scp->ipi_desc[id].handler = NULL; + scp->ipi_desc[id].priv = NULL; + scp_ipi_unlock(scp, id); +} +EXPORT_SYMBOL_GPL(scp_ipi_unregister); + +/* + * scp_memcpy_aligned() - Copy src to dst, where dst is in SCP SRAM region. + * + * @dst: Pointer to the destination buffer, should be in SCP SRAM region. + * @src: Pointer to the source buffer. + * @len: Length of the source buffer to be copied. + * + * Since AP access of SCP SRAM don't support byte write, this always write a + * full word at a time, and may cause some extra bytes to be written at the + * beginning & ending of dst. + */ +void scp_memcpy_aligned(void __iomem *dst, const void *src, unsigned int len) +{ + void __iomem *ptr; + u32 val; + unsigned int i = 0, remain; + + if (!IS_ALIGNED((unsigned long)dst, 4)) { + ptr = (void __iomem *)ALIGN_DOWN((unsigned long)dst, 4); + i = 4 - (dst - ptr); + val = readl_relaxed(ptr); + memcpy((u8 *)&val + (4 - i), src, i); + writel_relaxed(val, ptr); + } + + __iowrite32_copy(dst + i, src + i, (len - i) / 4); + remain = (len - i) % 4; + + if (remain > 0) { + val = readl_relaxed(dst + len - remain); + memcpy(&val, src + len - remain, remain); + writel_relaxed(val, dst + len - remain); + } +} +EXPORT_SYMBOL_GPL(scp_memcpy_aligned); + +/** + * scp_ipi_lock() - Lock before operations of an IPI ID + * + * @scp: mtk_scp structure + * @id: IPI ID + * + * Note: This should not be used by drivers other than mtk_scp. + */ +void scp_ipi_lock(struct mtk_scp *scp, u32 id) +{ + if (WARN_ON(id >= SCP_IPI_MAX)) + return; + mutex_lock(&scp->ipi_desc[id].lock); +} +EXPORT_SYMBOL_GPL(scp_ipi_lock); + +/** + * scp_ipi_lock() - Unlock after operations of an IPI ID + * + * @scp: mtk_scp structure + * @id: IPI ID + * + * Note: This should not be used by drivers other than mtk_scp. + */ +void scp_ipi_unlock(struct mtk_scp *scp, u32 id) +{ + if (WARN_ON(id >= SCP_IPI_MAX)) + return; + mutex_unlock(&scp->ipi_desc[id].lock); +} +EXPORT_SYMBOL_GPL(scp_ipi_unlock); + +/** + * scp_ipi_send() - send data from AP to scp. + * + * @scp: mtk_scp structure + * @id: IPI ID + * @buf: the data buffer + * @len: the data buffer length + * @wait: number of msecs to wait for ack. 0 to skip waiting. + * + * This function is thread-safe. When this function returns, + * SCP has received the data and starts the processing. + * When the processing completes, IPI handler registered + * by scp_ipi_register will be called in interrupt context. + * + * Returns 0 if sending data successfully, -error on error. + **/ +int scp_ipi_send(struct mtk_scp *scp, u32 id, void *buf, unsigned int len, + unsigned int wait) +{ + struct mtk_share_obj __iomem *send_obj = scp->send_buf; + unsigned long timeout; + int ret; + + if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) || + WARN_ON(id == SCP_IPI_NS_SERVICE) || + WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf)) + return -EINVAL; + + mutex_lock(&scp->send_lock); + + ret = clk_prepare_enable(scp->clk); + if (ret) { + dev_err(scp->dev, "failed to enable clock\n"); + goto unlock_mutex; + } + + /* Wait until SCP receives the last command */ + timeout = jiffies + msecs_to_jiffies(2000); + do { + if (time_after(jiffies, timeout)) { + dev_err(scp->dev, "%s: IPI timeout!\n", __func__); + ret = -ETIMEDOUT; + goto clock_disable; + } + } while (readl(scp->reg_base + MT8183_HOST_TO_SCP)); + + scp_memcpy_aligned(send_obj->share_buf, buf, len); + + writel(len, &send_obj->len); + writel(id, &send_obj->id); + + scp->ipi_id_ack[id] = false; + /* send the command to SCP */ + writel(MT8183_HOST_IPC_INT_BIT, scp->reg_base + MT8183_HOST_TO_SCP); + + if (wait) { + /* wait for SCP's ACK */ + timeout = msecs_to_jiffies(wait); + ret = wait_event_timeout(scp->ack_wq, + scp->ipi_id_ack[id], + timeout); + scp->ipi_id_ack[id] = false; + if (WARN(!ret, "scp ipi %d ack time out !", id)) + ret = -EIO; + else + ret = 0; + } + +clock_disable: + clk_disable_unprepare(scp->clk); +unlock_mutex: + mutex_unlock(&scp->send_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(scp_ipi_send); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("MediaTek scp IPI interface"); |