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authorErin Lo <erin.lo@mediatek.com>2019-11-12 12:03:25 +0100
committerBjorn Andersson <bjorn.andersson@linaro.org>2020-01-20 19:29:54 +0100
commit63c13d61eafe4606f1c16c54da40c4eee78e9edf (patch)
tree7e79d8cc72fc3b4a6672cd9ec5fadeb38a34251e /drivers/remoteproc/mtk_scp_ipi.c
parentdt-bindings: Add a binding for Mediatek SCP (diff)
downloadlinux-63c13d61eafe4606f1c16c54da40c4eee78e9edf.tar.xz
linux-63c13d61eafe4606f1c16c54da40c4eee78e9edf.zip
remoteproc/mediatek: add SCP support for mt8183
Provide a basic driver to control Cortex M4 co-processor Signed-off-by: Erin Lo <erin.lo@mediatek.com> Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org> Link: https://lore.kernel.org/r/20191112110330.179649-3-pihsun@chromium.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/remoteproc/mtk_scp_ipi.c')
-rw-r--r--drivers/remoteproc/mtk_scp_ipi.c218
1 files changed, 218 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..abdb7944368a
--- /dev/null
+++ b/drivers/remoteproc/mtk_scp_ipi.c
@@ -0,0 +1,218 @@
+// 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(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");