2017-08-17 10:17:58

by Wright Feng

[permalink] [raw]
Subject: [PATCH v2] brcmfmac: add CLM download support

From: Chung-Hsien Hsu <[email protected]>

The firmware for brcmfmac devices includes information regarding
regulatory constraints. For certain devices this information is kept
separately in a binary form that needs to be downloaded to the device.
This patch adds support to download this so-called CLM blob file. It
uses the same naming scheme as the other firmware files with extension
of .clm_blob.

The CLM blob file is optional. If the file does not exist, the download
process will be bypassed. It will not affect the driver loading.

Signed-off-by: Chung-Hsien Hsu <[email protected]>
---
v2: Revise commit message to describe in more detail
---
.../net/wireless/broadcom/brcm80211/brcmfmac/bus.h | 10 ++
.../wireless/broadcom/brcm80211/brcmfmac/common.c | 156 +++++++++++++++++++++
.../wireless/broadcom/brcm80211/brcmfmac/core.c | 2 +
.../wireless/broadcom/brcm80211/brcmfmac/core.h | 2 +
.../broadcom/brcm80211/brcmfmac/fwil_types.h | 31 ++++
.../wireless/broadcom/brcm80211/brcmfmac/pcie.c | 19 +++
.../wireless/broadcom/brcm80211/brcmfmac/sdio.c | 19 +++
.../net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 18 +++
8 files changed, 257 insertions(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
index b55c329..df42e09 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
@@ -71,6 +71,7 @@ struct brcmf_bus_dcmd {
* @wowl_config: specify if dongle is configured for wowl when going to suspend
* @get_ramsize: obtain size of device memory.
* @get_memdump: obtain device memory dump in provided buffer.
+ * @get_fwname: obtain firmware name.
*
* This structure provides an abstract interface towards the
* bus specific driver. For control messages to common driver
@@ -87,6 +88,8 @@ struct brcmf_bus_ops {
void (*wowl_config)(struct device *dev, bool enabled);
size_t (*get_ramsize)(struct device *dev);
int (*get_memdump)(struct device *dev, void *data, size_t len);
+ int (*get_fwname)(struct device *dev, uint chip, uint chiprev,
+ unsigned char *fw_name);
};


@@ -214,6 +217,13 @@ int brcmf_bus_get_memdump(struct brcmf_bus *bus, void *data, size_t len)
return bus->ops->get_memdump(bus->dev, data, len);
}

+static inline
+int brcmf_bus_get_fwname(struct brcmf_bus *bus, uint chip, uint chiprev,
+ unsigned char *fw_name)
+{
+ return bus->ops->get_fwname(bus->dev, chip, chiprev, fw_name);
+}
+
/*
* interface functions from common layer
*/
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
index 7a2b495..6d30421 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
@@ -18,6 +18,7 @@
#include <linux/string.h>
#include <linux/netdevice.h>
#include <linux/module.h>
+#include <linux/firmware.h>
#include <brcmu_wifi.h>
#include <brcmu_utils.h>
#include "core.h"
@@ -28,6 +29,7 @@
#include "tracepoint.h"
#include "common.h"
#include "of.h"
+#include "firmware.h"

MODULE_AUTHOR("Broadcom Corporation");
MODULE_DESCRIPTION("Broadcom 802.11 wireless LAN fullmac driver.");
@@ -104,12 +106,134 @@ void brcmf_c_set_joinpref_default(struct brcmf_if *ifp)
brcmf_err("Set join_pref error (%d)\n", err);
}

+static int brcmf_c_download(struct brcmf_if *ifp, u16 flag,
+ struct brcmf_dload_data_le *dload_buf,
+ u32 len)
+{
+ u16 flags;
+ s32 err;
+
+ flags = flag | (DLOAD_HANDLER_VER << DLOAD_FLAG_VER_SHIFT);
+ dload_buf->flag = cpu_to_le16(flags);
+ dload_buf->dload_type = cpu_to_le16(DL_TYPE_CLM);
+ dload_buf->len = cpu_to_le32(len);
+ dload_buf->crc = cpu_to_le32(0);
+ len = len + 8 - (len % 8);
+
+ err = brcmf_fil_iovar_data_set(ifp, "clmload", (void *)dload_buf, len);
+
+ return err;
+}
+
+static int brcmf_c_get_clm_name(struct brcmf_if *ifp, u8 *clm_name)
+{
+ struct brcmf_bus *bus = ifp->drvr->bus_if;
+ struct brcmf_rev_info *ri = &ifp->drvr->revinfo;
+ u8 fw_name[BRCMF_FW_NAME_LEN];
+ u8 *ptr;
+ size_t len;
+ s32 err;
+
+ memset(fw_name, 0, BRCMF_FW_NAME_LEN);
+ err = brcmf_bus_get_fwname(bus, ri->chipnum, ri->chiprev, fw_name);
+ if (err) {
+ brcmf_err("get firmware name failed (%d)\n", err);
+ goto done;
+ }
+
+ /* generate CLM blob file name */
+ ptr = strrchr(fw_name, '.');
+ len = ptr - fw_name + 1;
+ if (len + strlen(".clm_blob") > BRCMF_FW_NAME_LEN) {
+ err = -E2BIG;
+ } else {
+ strlcpy(clm_name, fw_name, len);
+ strlcat(clm_name, ".clm_blob", BRCMF_FW_NAME_LEN);
+ }
+done:
+ return err;
+}
+
+static int brcmf_c_process_clm_blob(struct brcmf_if *ifp)
+{
+ struct device *dev = ifp->drvr->bus_if->dev;
+ struct brcmf_dload_data_le *chunk_buf;
+ const struct firmware *clm = NULL;
+ u8 clm_name[BRCMF_FW_NAME_LEN];
+ u32 chunk_len;
+ u32 datalen;
+ u32 cumulative_len = 0;
+ u16 dl_flag = DL_BEGIN;
+ u32 status;
+ s32 err;
+
+ brcmf_dbg(INFO, "Enter\n");
+
+ memset(clm_name, 0, BRCMF_FW_NAME_LEN);
+ err = brcmf_c_get_clm_name(ifp, clm_name);
+ if (err) {
+ brcmf_err("get CLM blob file name failed (%d)\n", err);
+ return err;
+ }
+
+ err = request_firmware(&clm, clm_name, dev);
+ if (err) {
+ if (err == -ENOENT)
+ return 0;
+ brcmf_err("request CLM blob file failed (%d)\n", err);
+ return err;
+ }
+
+ datalen = clm->size;
+
+ chunk_buf = kzalloc(sizeof(*chunk_buf) + MAX_CHUNK_LEN - 1, GFP_KERNEL);
+ if (!chunk_buf) {
+ err = -ENOMEM;
+ goto done;
+ }
+
+ do {
+ if (datalen > MAX_CHUNK_LEN) {
+ chunk_len = MAX_CHUNK_LEN;
+ } else {
+ chunk_len = datalen;
+ dl_flag |= DL_END;
+ }
+ memcpy(chunk_buf->data, clm->data + cumulative_len, chunk_len);
+
+ err = brcmf_c_download(ifp, dl_flag, chunk_buf, chunk_len);
+
+ dl_flag &= ~DL_BEGIN;
+
+ cumulative_len += chunk_len;
+ datalen -= chunk_len;
+ } while ((datalen > 0) && (err == 0));
+
+ if (err) {
+ brcmf_err("clmload (%d byte file) failed (%d); ",
+ (u32)clm->size, err);
+ /* Retrieve clmload_status and print */
+ err = brcmf_fil_iovar_int_get(ifp, "clmload_status", &status);
+ if (err)
+ brcmf_err("get clmload_status failed (%d)\n", err);
+ else
+ brcmf_dbg(INFO, "clmload_status=%d\n", status);
+ err = -EIO;
+ }
+
+ kfree(chunk_buf);
+done:
+ release_firmware(clm);
+ return err;
+}
+
int brcmf_c_preinit_dcmds(struct brcmf_if *ifp)
{
s8 eventmask[BRCMF_EVENTING_MASK_LEN];
u8 buf[BRCMF_DCMD_SMLEN];
struct brcmf_rev_info_le revinfo;
struct brcmf_rev_info *ri;
+ char *clmver;
char *ptr;
s32 err;

@@ -148,6 +272,13 @@ int brcmf_c_preinit_dcmds(struct brcmf_if *ifp)
}
ri->result = err;

+ /* Do any CLM downloading */
+ err = brcmf_c_process_clm_blob(ifp);
+ if (err < 0) {
+ brcmf_err("download CLM blob file failed, %d\n", err);
+ goto done;
+ }
+
/* query for 'ver' to get version info from firmware */
memset(buf, 0, sizeof(buf));
strcpy(buf, "ver");
@@ -167,6 +298,31 @@ int brcmf_c_preinit_dcmds(struct brcmf_if *ifp)
ptr = strrchr(buf, ' ') + 1;
strlcpy(ifp->drvr->fwver, ptr, sizeof(ifp->drvr->fwver));

+ /* Query for 'clmver' to get CLM version info from firmware */
+ memset(buf, 0, sizeof(buf));
+ err = brcmf_fil_iovar_data_get(ifp, "clmver", buf, sizeof(buf));
+ if (err) {
+ if (err == -23) {
+ brcmf_dbg(INFO, "clmver iovar unsupported, %d\n", err);
+ } else {
+ brcmf_err("retrieving clmver failed, %d\n", err);
+ goto done;
+ }
+ } else {
+ clmver = (char *)buf;
+ /* store CLM version for adding it to revinfo debugfs file */
+ memcpy(ifp->drvr->clmver, clmver, sizeof(ifp->drvr->clmver));
+
+ /* Replace all newline/linefeed characters with space
+ * character
+ */
+ ptr = clmver;
+ while ((ptr = strnchr(ptr, '\n', sizeof(buf))) != NULL)
+ *ptr = ' ';
+
+ brcmf_dbg(INFO, "CLM version = %s\n", clmver);
+ }
+
/* set mpc */
err = brcmf_fil_iovar_int_set(ifp, "mpc", 1);
if (err) {
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
index 511d190..7414dff 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
@@ -941,6 +941,8 @@ static int brcmf_revinfo_read(struct seq_file *s, void *data)
seq_printf(s, "anarev: %u\n", ri->anarev);
seq_printf(s, "nvramrev: %08x\n", ri->nvramrev);

+ seq_printf(s, "clmrev: %s\n", bus_if->drvr->clmver);
+
return 0;
}

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
index a4dd313..ae39128 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
@@ -141,6 +141,8 @@ struct brcmf_pub {
struct notifier_block inetaddr_notifier;
struct notifier_block inet6addr_notifier;
struct brcmf_mp_device *settings;
+
+ u8 clmver[BRCMF_DCMD_SMLEN];
};

/* forward declarations */
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
index 9a1eb5a..fffe347 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
@@ -147,6 +147,21 @@
#define BRCMF_MFP_CAPABLE 1
#define BRCMF_MFP_REQUIRED 2

+/* MAX_CHUNK_LEN is the maximum length for data passing to firmware in each
+ * ioctl. It is relatively small because firmware has small maximum size input
+ * playload restriction for ioctls.
+ */
+#define MAX_CHUNK_LEN 1400
+
+#define DLOAD_HANDLER_VER 1 /* Downloader version */
+#define DLOAD_FLAG_VER_MASK 0xf000 /* Downloader version mask */
+#define DLOAD_FLAG_VER_SHIFT 12 /* Downloader version shift */
+
+#define DL_BEGIN 0x0002
+#define DL_END 0x0004
+
+#define DL_TYPE_CLM 2
+
/* join preference types for join_pref iovar */
enum brcmf_join_pref_types {
BRCMF_JOIN_PREF_RSSI = 1,
@@ -835,4 +850,20 @@ struct brcmf_gtk_keyinfo_le {
u8 replay_counter[BRCMF_RSN_REPLAY_LEN];
};

+/**
+ * struct brcmf_dload_data_le - data passing to firmware for downloading
+ * @flag: flags related to download data.
+ * @dload_type: type of download data.
+ * @len: length in bytes of download data.
+ * @crc: crc of download data.
+ * @data: download data.
+ */
+struct brcmf_dload_data_le {
+ __le16 flag;
+ __le16 dload_type;
+ __le32 len;
+ __le32 crc;
+ u8 data[1];
+};
+
#endif /* FWIL_TYPES_H_ */
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
index f878706..b370ee7 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
@@ -1350,6 +1350,24 @@ static int brcmf_pcie_get_memdump(struct device *dev, void *data, size_t len)
return 0;
}

+static int brcmf_pcie_get_fwname(struct device *dev, u32 chip, u32 chiprev,
+ u8 *fw_name)
+{
+ struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+ struct brcmf_pciedev *buspub = bus_if->bus_priv.pcie;
+ struct brcmf_pciedev_info *devinfo = buspub->devinfo;
+ int ret = 0;
+
+ if (devinfo->fw_name[0] != '\0')
+ strlcpy(fw_name, devinfo->fw_name, BRCMF_FW_NAME_LEN);
+ else
+ ret = brcmf_fw_map_chip_to_name(chip, chiprev,
+ brcmf_pcie_fwnames,
+ ARRAY_SIZE(brcmf_pcie_fwnames),
+ fw_name, NULL);
+
+ return ret;
+}

static const struct brcmf_bus_ops brcmf_pcie_bus_ops = {
.txdata = brcmf_pcie_tx,
@@ -1359,6 +1377,7 @@ static int brcmf_pcie_get_memdump(struct device *dev, void *data, size_t len)
.wowl_config = brcmf_pcie_wowl_config,
.get_ramsize = brcmf_pcie_get_ramsize,
.get_memdump = brcmf_pcie_get_memdump,
+ .get_fwname = brcmf_pcie_get_fwname,
};


diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 5653d6d..038c75e 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -3970,6 +3970,24 @@ static void brcmf_sdio_buscore_write32(void *ctx, u32 addr, u32 val)
}
}

+static int brcmf_sdio_get_fwname(struct device *dev, u32 chip, u32 chiprev,
+ u8 *fw_name)
+{
+ struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+ struct brcmf_sdio_dev *sdiodev = bus_if->bus_priv.sdio;
+ int ret = 0;
+
+ if (sdiodev->fw_name[0] != '\0')
+ strlcpy(fw_name, sdiodev->fw_name, BRCMF_FW_NAME_LEN);
+ else
+ ret = brcmf_fw_map_chip_to_name(chip, chiprev,
+ brcmf_sdio_fwnames,
+ ARRAY_SIZE(brcmf_sdio_fwnames),
+ fw_name, NULL);
+
+ return ret;
+}
+
static const struct brcmf_bus_ops brcmf_sdio_bus_ops = {
.stop = brcmf_sdio_bus_stop,
.preinit = brcmf_sdio_bus_preinit,
@@ -3980,6 +3998,7 @@ static void brcmf_sdio_buscore_write32(void *ctx, u32 addr, u32 val)
.wowl_config = brcmf_sdio_wowl_config,
.get_ramsize = brcmf_sdio_bus_get_ramsize,
.get_memdump = brcmf_sdio_bus_get_memdump,
+ .get_fwname = brcmf_sdio_get_fwname,
};

static void brcmf_sdio_firmware_callback(struct device *dev, int err,
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index 0eea48e..f00016f 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -1126,12 +1126,30 @@ static void brcmf_usb_wowl_config(struct device *dev, bool enabled)
device_set_wakeup_enable(devinfo->dev, false);
}

+static int brcmf_usb_get_fwname(struct device *dev, u32 chip, u32 chiprev,
+ u8 *fw_name)
+{
+ struct brcmf_usbdev_info *devinfo = brcmf_usb_get_businfo(dev);
+ int ret = 0;
+
+ if (devinfo->fw_name[0] != '\0')
+ strlcpy(fw_name, devinfo->fw_name, BRCMF_FW_NAME_LEN);
+ else
+ ret = brcmf_fw_map_chip_to_name(chip, chiprev,
+ brcmf_usb_fwnames,
+ ARRAY_SIZE(brcmf_usb_fwnames),
+ fw_name, NULL);
+
+ return ret;
+}
+
static const struct brcmf_bus_ops brcmf_usb_bus_ops = {
.txdata = brcmf_usb_tx,
.stop = brcmf_usb_down,
.txctl = brcmf_usb_tx_ctlpkt,
.rxctl = brcmf_usb_rx_ctlpkt,
.wowl_config = brcmf_usb_wowl_config,
+ .get_fwname = brcmf_usb_get_fwname,
};

static int brcmf_usb_bus_setup(struct brcmf_usbdev_info *devinfo)
--
1.9.1


2017-08-17 19:03:03

by Stefan Wahren

[permalink] [raw]
Subject: Re: [PATCH v2] brcmfmac: add CLM download support

Hi,

> Wright Feng <[email protected]> hat am 17. August 2017 um 12:22 geschrieben:
>
>
> From: Chung-Hsien Hsu <[email protected]>
>
> The firmware for brcmfmac devices includes information regarding
> regulatory constraints. For certain devices this information is kept
> separately in a binary form that needs to be downloaded to the device.
> This patch adds support to download this so-called CLM blob file. It
> uses the same naming scheme as the other firmware files with extension
> of .clm_blob.
>
> The CLM blob file is optional. If the file does not exist, the download
> process will be bypassed. It will not affect the driver loading.
>
> Signed-off-by: Chung-Hsien Hsu <[email protected]>
> ---
> v2: Revise commit message to describe in more detail
> ---
> .../net/wireless/broadcom/brcm80211/brcmfmac/bus.h | 10 ++
> .../wireless/broadcom/brcm80211/brcmfmac/common.c | 156 +++++++++++++++++++++
> .../wireless/broadcom/brcm80211/brcmfmac/core.c | 2 +
> .../wireless/broadcom/brcm80211/brcmfmac/core.h | 2 +
> .../broadcom/brcm80211/brcmfmac/fwil_types.h | 31 ++++
> .../wireless/broadcom/brcm80211/brcmfmac/pcie.c | 19 +++
> .../wireless/broadcom/brcm80211/brcmfmac/sdio.c | 19 +++
> .../net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 18 +++
> 8 files changed, 257 insertions(+)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
> index b55c329..df42e09 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
> @@ -71,6 +71,7 @@ struct brcmf_bus_dcmd {
> * @wowl_config: specify if dongle is configured for wowl when going to suspend
> * @get_ramsize: obtain size of device memory.
> * @get_memdump: obtain device memory dump in provided buffer.
> + * @get_fwname: obtain firmware name.
> *
> * This structure provides an abstract interface towards the
> * bus specific driver. For control messages to common driver
> @@ -87,6 +88,8 @@ struct brcmf_bus_ops {
> void (*wowl_config)(struct device *dev, bool enabled);
> size_t (*get_ramsize)(struct device *dev);
> int (*get_memdump)(struct device *dev, void *data, size_t len);
> + int (*get_fwname)(struct device *dev, uint chip, uint chiprev,
> + unsigned char *fw_name);
> };
>
>
> @@ -214,6 +217,13 @@ int brcmf_bus_get_memdump(struct brcmf_bus *bus, void *data, size_t len)
> return bus->ops->get_memdump(bus->dev, data, len);
> }
>
> +static inline
> +int brcmf_bus_get_fwname(struct brcmf_bus *bus, uint chip, uint chiprev,
> + unsigned char *fw_name)
> +{
> + return bus->ops->get_fwname(bus->dev, chip, chiprev, fw_name);
> +}
> +
> /*
> * interface functions from common layer
> */
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
> index 7a2b495..6d30421 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
> @@ -18,6 +18,7 @@
> #include <linux/string.h>
> #include <linux/netdevice.h>
> #include <linux/module.h>
> +#include <linux/firmware.h>
> #include <brcmu_wifi.h>
> #include <brcmu_utils.h>
> #include "core.h"
> @@ -28,6 +29,7 @@
> #include "tracepoint.h"
> #include "common.h"
> #include "of.h"
> +#include "firmware.h"
>
> MODULE_AUTHOR("Broadcom Corporation");
> MODULE_DESCRIPTION("Broadcom 802.11 wireless LAN fullmac driver.");
> @@ -104,12 +106,134 @@ void brcmf_c_set_joinpref_default(struct brcmf_if *ifp)
> brcmf_err("Set join_pref error (%d)\n", err);
> }
>
> +static int brcmf_c_download(struct brcmf_if *ifp, u16 flag,
> + struct brcmf_dload_data_le *dload_buf,
> + u32 len)
> +{
> + u16 flags;
> + s32 err;
> +
> + flags = flag | (DLOAD_HANDLER_VER << DLOAD_FLAG_VER_SHIFT);
> + dload_buf->flag = cpu_to_le16(flags);
> + dload_buf->dload_type = cpu_to_le16(DL_TYPE_CLM);
> + dload_buf->len = cpu_to_le32(len);
> + dload_buf->crc = cpu_to_le32(0);
> + len = len + 8 - (len % 8);
> +
> + err = brcmf_fil_iovar_data_set(ifp, "clmload", (void *)dload_buf, len);
> +
> + return err;
> +}
> +
> +static int brcmf_c_get_clm_name(struct brcmf_if *ifp, u8 *clm_name)
> +{
> + struct brcmf_bus *bus = ifp->drvr->bus_if;
> + struct brcmf_rev_info *ri = &ifp->drvr->revinfo;
> + u8 fw_name[BRCMF_FW_NAME_LEN];
> + u8 *ptr;
> + size_t len;
> + s32 err;
> +
> + memset(fw_name, 0, BRCMF_FW_NAME_LEN);
> + err = brcmf_bus_get_fwname(bus, ri->chipnum, ri->chiprev, fw_name);
> + if (err) {
> + brcmf_err("get firmware name failed (%d)\n", err);
> + goto done;
> + }
> +
> + /* generate CLM blob file name */
> + ptr = strrchr(fw_name, '.');

maybe it's very unlikely that the firmware name doesn't contain a dot, but i think we should care about the error case.

> + len = ptr - fw_name + 1;
> + if (len + strlen(".clm_blob") > BRCMF_FW_NAME_LEN) {
> + err = -E2BIG;
> + } else {
> + strlcpy(clm_name, fw_name, len);
> + strlcat(clm_name, ".clm_blob", BRCMF_FW_NAME_LEN);
> + }
> +done:
> + return err;
> +}
> +