[RFC PATCH V2 5/6] remoteproc/mediatek: add SCP's shared dma pool support for mt8183

frederic.chen-NuS5LvNUpcJWk0Htik3J/w
2019-07-08T11:04:59Z

From: Frederic Chen <frederic.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

This patch uses of_reserved_mem_device_init_by_idx() to hook the
scp device to DMA mapping API to provide a shared dma pool of
SCP DMA buffers for SCP's client such as DIP and ISP Pass 1
drivers.

Signed-off-by: Frederic Chen <frederic.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
drivers/remoteproc/mtk_scp.c | 54 ++++++++++++++++++++++--------------
1 file changed, 33 insertions(+), 21 deletions(-)

diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index 4c093dec52b9..0cffe4b63dba 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -4,12 +4,14 @@

#include <asm/barrier.h>
#include <linux/clk.h>
+#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
#include <linux/platform_data/mtk_scp.h>
#include <linux/platform_device.h>
#include <linux/remoteproc.h>
@@ -487,29 +489,29 @@ EXPORT_SYMBOL_GPL(scp_get_reserve_mem_size);

static int scp_map_memory_region(struct mtk_scp *scp)
{
- struct device_node *node;
- struct resource r;
- int ret;
+ int ret, id;

- node = of_parse_phandle(scp->dev->of_node, "memory-region", 0);
- if (!node) {
- dev_err(scp->dev, "no memory-region specified\n");
- return -EINVAL;
+ ret = of_reserved_mem_device_init_by_idx(scp->dev, scp->dev->of_node,
+ 0);
+ if (ret) {
+ dev_err(scp->dev,
+ "%s:of_reserved_mem_device_init_by_idx(0) failed:(%d)",
+ __func__, ret);
+ return -ENOMEM;
}

- ret = of_address_to_resource(node, 0, &r);
- if (ret)
- return ret;
+ /* Pre-allocate the working buffers */
+ scp->dram_size = MAX_CODE_SIZE;
+ for (id = 0; id < SCP_NUMS_MEM_ID; id++)
+ scp->dram_size += scp_reserve_mblock[id].size;

- scp->phys_addr = r.start;
- scp->dram_size = resource_size(&r);
- scp->cpu_addr =
- devm_ioremap_wc(scp->dev, scp->phys_addr, scp->dram_size);
+ scp->cpu_addr = dma_alloc_coherent(scp->dev, scp->dram_size,
+ &scp->phys_addr, GFP_KERNEL);

if (!scp->cpu_addr) {
- dev_err(scp->dev, "unable to map memory region: %pa+%zx\n",
- &r.start, scp->dram_size);
- return -EBUSY;
+ dev_err(scp->dev, "unable to pre-allocate memory for SCP: %zx\n",
+ scp->dram_size);
+ return -ENOMEM;
}

#if SCP_RESERVED_MEM
@@ -519,6 +521,13 @@ static int scp_map_memory_region(struct mtk_scp *scp)
return 0;
}

+static void scp_unmap_memory_region(struct mtk_scp *scp)
+{
+ dma_free_coherent(scp->dev, scp->dram_size, scp->cpu_addr,
+ scp->phys_addr);
+ of_reserved_mem_device_release(scp->dev);
+}
+
static struct mtk_rpmsg_info mtk_scp_rpmsg_info = {
.send_ipi = scp_ipi_send,
.register_ipi = scp_ipi_register,
@@ -594,20 +603,20 @@ static int scp_probe(struct platform_device *pdev)
if (IS_ERR(scp->clk)) {
dev_err(dev, "Failed to get clock\n");
ret = PTR_ERR(scp->clk);
- goto free_rproc;
+ goto release_dev_mem;
}

ret = clk_prepare_enable(scp->clk);
if (ret) {
dev_err(dev, "failed to enable clocks\n");
- goto free_rproc;
+ goto release_dev_mem;
}

ret = scp_ipi_init(scp);
clk_disable_unprepare(scp->clk);
if (ret) {
dev_err(dev, "Failed to init ipi\n");
- goto free_rproc;
+ goto release_dev_mem;
}

/* register SCP initialization IPI */
@@ -617,7 +626,7 @@ static int scp_probe(struct platform_device *pdev)
scp);
if (ret) {
dev_err(dev, "Failed to register IPI_SCP_INIT\n");
- goto free_rproc;
+ goto release_dev_mem;
}

mutex_init(&scp->lock);
@@ -645,6 +654,8 @@ static int scp_probe(struct platform_device *pdev)
remove_subdev:
scp_remove_rpmsg_subdev(scp);
mutex_destroy(&scp->lock);
+release_dev_mem:
+ scp_unmap_memory_region(scp);
free_rproc:
rproc_free(rproc);

@@ -658,6 +669,7 @@ static int scp_remove(struct platform_device *pdev)
scp_remove_rpmsg_subdev(scp);
rproc_del(scp->rproc);
rproc_free(scp->rproc);
+ scp_unmap_memory_region(scp);

return 0;
}
--
2.18.0