[PATCH 4/6] memory: brcmstb: dpfe: prepare support for multiple API versions

From: Markus Mayer
Date: Tue Apr 02 2019 - 19:10:50 EST


From: Markus Mayer <mmayer@xxxxxxxxxxxx>

Extend the driver, so it can handle different API versions for
interacting with the DCPU. This is in preparation for the upcoming API
v3.

Signed-off-by: Markus Mayer <mmayer@xxxxxxxxxxxx>
---
drivers/memory/brcmstb_dpfe.c | 87 ++++++++++++++++++++++++-----------
1 file changed, 59 insertions(+), 28 deletions(-)

diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c
index f8d05a8266c3..9ad5ea08c134 100644
--- a/drivers/memory/brcmstb_dpfe.c
+++ b/drivers/memory/brcmstb_dpfe.c
@@ -35,10 +35,10 @@
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>

#define DRVNAME "brcmstb-dpfe"
-#define FIRMWARE_NAME "dpfe.bin"

/* DCPU register offsets */
#define REG_DCPU_RESET 0x0
@@ -164,12 +164,20 @@ struct init_data {
bool is_big_endian;
};

+/* API version and corresponding commands */
+struct dpfe_api {
+ int version;
+ const char *fw_name;
+ u32 command[DPFE_CMD_MAX][MSG_FIELD_MAX];
+};
+
/* Things we need for as long as we are active. */
struct private_data {
void __iomem *regs;
void __iomem *dmem;
void __iomem *imem;
struct device *dev;
+ const struct dpfe_api *dpfe_api;
struct mutex lock;
};

@@ -178,29 +186,33 @@ static const char *error_text[] = {
"Incorrect checksum", "Malformed command", "Timed out",
};

-/* List of supported firmware commands */
-static const u32 dpfe_commands[DPFE_CMD_MAX][MSG_FIELD_MAX] = {
- [DPFE_CMD_GET_INFO] = {
- [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
- [MSG_COMMAND] = 1,
- [MSG_ARG_COUNT] = 1,
- [MSG_ARG0] = 1,
- [MSG_CHKSUM] = 4,
- },
- [DPFE_CMD_GET_REFRESH] = {
- [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
- [MSG_COMMAND] = 2,
- [MSG_ARG_COUNT] = 1,
- [MSG_ARG0] = 1,
- [MSG_CHKSUM] = 5,
- },
- [DPFE_CMD_GET_VENDOR] = {
- [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
- [MSG_COMMAND] = 2,
- [MSG_ARG_COUNT] = 1,
- [MSG_ARG0] = 2,
- [MSG_CHKSUM] = 6,
- },
+/* API v2 firmware commands */
+static const struct dpfe_api dpfe_api_v2 = {
+ .version = 2,
+ .fw_name = "dpfe.bin",
+ .command = {
+ [DPFE_CMD_GET_INFO] = {
+ [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
+ [MSG_COMMAND] = 1,
+ [MSG_ARG_COUNT] = 1,
+ [MSG_ARG0] = 1,
+ [MSG_CHKSUM] = 4,
+ },
+ [DPFE_CMD_GET_REFRESH] = {
+ [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
+ [MSG_COMMAND] = 2,
+ [MSG_ARG_COUNT] = 1,
+ [MSG_ARG0] = 1,
+ [MSG_CHKSUM] = 5,
+ },
+ [DPFE_CMD_GET_VENDOR] = {
+ [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
+ [MSG_COMMAND] = 2,
+ [MSG_ARG_COUNT] = 1,
+ [MSG_ARG0] = 2,
+ [MSG_CHKSUM] = 6,
+ },
+ }
};

static bool is_dcpu_enabled(void __iomem *regs)
@@ -293,7 +305,7 @@ static void __iomem *get_msg_ptr(struct private_data *priv, u32 response,
static int __send_command(struct private_data *priv, unsigned int cmd,
u32 result[])
{
- const u32 *msg = dpfe_commands[cmd];
+ const u32 *msg = priv->dpfe_api->command[cmd];
void __iomem *regs = priv->regs;
unsigned int i, chksum;
int ret = 0;
@@ -492,7 +504,15 @@ static int brcmstb_dpfe_download_firmware(struct platform_device *pdev,
return 0;
}

- ret = request_firmware(&fw, FIRMWARE_NAME, dev);
+ /*
+ * If the firmware filename is NULL it means the boot firmware has to
+ * download the DCPU firmware for us. If that didn't work, we have to
+ * bail, since downloading it ourselves wouldn't work either.
+ */
+ if (!priv->dpfe_api->fw_name)
+ return -ENODEV;
+
+ ret = request_firmware(&fw, priv->dpfe_api->fw_name, dev);
/* request_firmware() prints its own error messages. */
if (ret)
return ret;
@@ -714,6 +734,16 @@ static int brcmstb_dpfe_probe(struct platform_device *pdev)
return -ENOENT;
}

+ priv->dpfe_api = of_device_get_match_data(dev);
+ if (unlikely(!priv->dpfe_api)) {
+ /*
+ * It should be impossible to end up here, but to be safe we
+ * check anyway.
+ */
+ dev_err(dev, "Couldn't determine API\n");
+ return -ENOENT;
+ }
+
ret = brcmstb_dpfe_download_firmware(pdev, &init);
if (ret) {
dev_err(dev, "Couldn't download firmware -- %d\n", ret);
@@ -722,7 +752,8 @@ static int brcmstb_dpfe_probe(struct platform_device *pdev)

ret = sysfs_create_groups(&pdev->dev.kobj, dpfe_groups);
if (!ret)
- dev_info(dev, "registered.\n");
+ dev_info(dev, "registered with API v%d.\n",
+ priv->dpfe_api->version);

return ret;
}
@@ -735,7 +766,7 @@ static int brcmstb_dpfe_remove(struct platform_device *pdev)
}

static const struct of_device_id brcmstb_dpfe_of_match[] = {
- { .compatible = "brcm,dpfe-cpu", },
+ { .compatible = "brcm,dpfe-cpu", .data = &dpfe_api_v2 },
{}
};
MODULE_DEVICE_TABLE(of, brcmstb_dpfe_of_match);
--
2.17.1