diff mbox series

[07/34] brcmfmac: pcie: Read Apple OTP information

Message ID 20211226153624.162281-8-marcan@marcan.st
State Superseded
Headers show
Series brcmfmac: Support Apple T2 and M1 platforms | expand

Commit Message

Hector Martin Dec. 26, 2021, 3:35 p.m. UTC
On Apple platforms, the One Time Programmable ROM in the Broadcom chips
contains information about the specific board design (module, vendor,
version) that is required to select the correct NVRAM file. Parse this
OTP ROM and extract the required strings.

Note that the user OTP offset/size is per-chip. This patch does not add
any chips yet.

Signed-off-by: Hector Martin <marcan@marcan.st>
---
 .../broadcom/brcm80211/brcmfmac/pcie.c        | 219 ++++++++++++++++++
 include/linux/bcma/bcma_driver_chipcommon.h   |   1 +
 2 files changed, 220 insertions(+)

Comments

Linus Walleij Jan. 2, 2022, 5:38 a.m. UTC | #1
On Sun, Dec 26, 2021 at 4:37 PM Hector Martin <marcan@marcan.st> wrote:

> On Apple platforms, the One Time Programmable ROM in the Broadcom chips
> contains information about the specific board design (module, vendor,
> version) that is required to select the correct NVRAM file. Parse this
> OTP ROM and extract the required strings.
>
> Note that the user OTP offset/size is per-chip. This patch does not add
> any chips yet.
>
> Signed-off-by: Hector Martin <marcan@marcan.st>

Overall looks fine!

> +       const char *chip_params;
> +       const char *module_params;

This variable name "module_params" is a bit confusing since loadable
kernel modules have params...

Can we think of another name and just put a comment that this
refers to the WiFi module building block?

Sometimes people talk about SoM:s (system-on-modules), so
maybe som_params or brcm_som_params?

Yours,
Linus Walleij
Hector Martin Jan. 3, 2022, 5:51 a.m. UTC | #2
On 2022/01/02 14:38, Linus Walleij wrote:
> On Sun, Dec 26, 2021 at 4:37 PM Hector Martin <marcan@marcan.st> wrote:
> 
>> On Apple platforms, the One Time Programmable ROM in the Broadcom chips
>> contains information about the specific board design (module, vendor,
>> version) that is required to select the correct NVRAM file. Parse this
>> OTP ROM and extract the required strings.
>>
>> Note that the user OTP offset/size is per-chip. This patch does not add
>> any chips yet.
>>
>> Signed-off-by: Hector Martin <marcan@marcan.st>
> 
> Overall looks fine!
> 
>> +       const char *chip_params;
>> +       const char *module_params;
> 
> This variable name "module_params" is a bit confusing since loadable
> kernel modules have params...
> 
> Can we think of another name and just put a comment that this
> refers to the WiFi module building block?
> 
> Sometimes people talk about SoM:s (system-on-modules), so
> maybe som_params or brcm_som_params?
> 
> Yours,
> Linus Walleij
> 

How about board_params, since we're already calling those things boards
elsewhere in the driver? That could refer to the board of a standalone
module, or an integrated board, which should cover all cases.
Linus Walleij Jan. 3, 2022, 11:13 a.m. UTC | #3
On Mon, Jan 3, 2022 at 6:52 AM Hector Martin <marcan@marcan.st> wrote:
> On 2022/01/02 14:38, Linus Walleij wrote:
> > On Sun, Dec 26, 2021 at 4:37 PM Hector Martin <marcan@marcan.st> wrote:
> >
> >> On Apple platforms, the One Time Programmable ROM in the Broadcom chips
> >> contains information about the specific board design (module, vendor,
> >> version) that is required to select the correct NVRAM file. Parse this
> >> OTP ROM and extract the required strings.
> >>
> >> Note that the user OTP offset/size is per-chip. This patch does not add
> >> any chips yet.
> >>
> >> Signed-off-by: Hector Martin <marcan@marcan.st>
> >
> > Overall looks fine!
> >
> >> +       const char *chip_params;
> >> +       const char *module_params;
> >
> > This variable name "module_params" is a bit confusing since loadable
> > kernel modules have params...
> >
> > Can we think of another name and just put a comment that this
> > refers to the WiFi module building block?
> >
> > Sometimes people talk about SoM:s (system-on-modules), so
> > maybe som_params or brcm_som_params?
> >
> > Yours,
> > Linus Walleij
> >
>
> How about board_params, since we're already calling those things boards
> elsewhere in the driver? That could refer to the board of a standalone
> module, or an integrated board, which should cover all cases.

Fair enough, go for board_params!

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
index 8888d6acb7f2..49cb5254fa6e 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
@@ -255,6 +255,15 @@  struct brcmf_pcie_core_info {
 	u32 wrapbase;
 };
 
+#define BRCMF_OTP_MAX_PARAM_LEN 16
+
+struct brcmf_otp_params {
+	char module[BRCMF_OTP_MAX_PARAM_LEN];
+	char vendor[BRCMF_OTP_MAX_PARAM_LEN];
+	char version[BRCMF_OTP_MAX_PARAM_LEN];
+	bool valid;
+};
+
 struct brcmf_pciedev_info {
 	enum brcmf_pcie_state state;
 	bool in_irq;
@@ -282,6 +291,7 @@  struct brcmf_pciedev_info {
 	void (*write_ptr)(struct brcmf_pciedev_info *devinfo, u32 mem_offset,
 			  u16 value);
 	struct brcmf_mp_device *settings;
+	struct brcmf_otp_params otp;
 };
 
 struct brcmf_pcie_ringbuf {
@@ -353,6 +363,14 @@  static void brcmf_pcie_setup(struct device *dev, int ret,
 static struct brcmf_fw_request *
 brcmf_pcie_prepare_fw_request(struct brcmf_pciedev_info *devinfo);
 
+static u16
+brcmf_pcie_read_reg16(struct brcmf_pciedev_info *devinfo, u32 reg_offset)
+{
+	void __iomem *address = devinfo->regs + reg_offset;
+
+	return ioread16(address);
+}
+
 static u32
 brcmf_pcie_read_reg32(struct brcmf_pciedev_info *devinfo, u32 reg_offset)
 {
@@ -539,6 +557,8 @@  brcmf_pcie_copy_dev_tomem(struct brcmf_pciedev_info *devinfo, u32 mem_offset,
 }
 
 
+#define READCC32(devinfo, reg) brcmf_pcie_read_reg32(devinfo, \
+		CHIPCREGOFFS(reg))
 #define WRITECC32(devinfo, reg, value) brcmf_pcie_write_reg32(devinfo, \
 		CHIPCREGOFFS(reg), value)
 
@@ -1758,6 +1778,199 @@  static const struct brcmf_buscore_ops brcmf_pcie_buscore_ops = {
 	.write32 = brcmf_pcie_buscore_write32,
 };
 
+#define BRCMF_OTP_SYS_VENDOR	0x15
+#define BRCMF_OTP_BRCM_CIS	0x80
+
+#define BRCMF_OTP_VENDOR_HDR	0x00000008
+
+static int
+brcmf_pcie_parse_otp_sys_vendor(struct brcmf_pciedev_info *devinfo,
+				u8 *data, size_t size)
+{
+	int idx = 4;
+	const char *chip_params;
+	const char *module_params;
+	const char *p;
+
+	/* 4-byte header and two empty strings */
+	if (size < 6)
+		return -EINVAL;
+
+	if (get_unaligned_le32(data) != BRCMF_OTP_VENDOR_HDR)
+		return -EINVAL;
+
+	chip_params = &data[idx];
+
+	/* Skip first string, including terminator */
+	idx += strnlen(chip_params, size - idx) + 1;
+	if (idx >= size)
+		return -EINVAL;
+
+	module_params = &data[idx];
+
+	/* Skip to terminator of second string */
+	idx += strnlen(module_params, size - idx);
+	if (idx >= size)
+		return -EINVAL;
+
+	/* At this point both strings are guaranteed NUL-terminated */
+	brcmf_dbg(PCIE, "OTP: chip_params='%s' module_params='%s'\n",
+		  chip_params, module_params);
+
+	p = module_params;
+	while (*p) {
+		char tag = *p++;
+		const char *end;
+		size_t len;
+
+		if (tag == ' ') /* Skip extra spaces */
+			continue;
+
+		if (*p++ != '=') /* implicit NUL check */
+			return -EINVAL;
+
+		/* *p might be NUL here, if so end == p and len == 0 */
+		end = strchrnul(p, ' ');
+		len = end - p;
+
+		/* leave 1 byte for NUL in destination string */
+		if (len > (BRCMF_OTP_MAX_PARAM_LEN - 1))
+			return -EINVAL;
+
+		/* Copy len characters plus a NUL terminator */
+		switch (tag) {
+		case 'M':
+			strscpy(devinfo->otp.module, p, len + 1);
+			break;
+		case 'V':
+			strscpy(devinfo->otp.vendor, p, len + 1);
+			break;
+		case 'm':
+			strscpy(devinfo->otp.version, p, len + 1);
+			break;
+		}
+
+		/* Skip to space separator or NUL */
+		p = end;
+	}
+
+	brcmf_dbg(PCIE, "OTP: module=%s vendor=%s version=%s\n",
+		  devinfo->otp.module, devinfo->otp.vendor,
+		  devinfo->otp.version);
+
+	if (!devinfo->otp.module ||
+	    !devinfo->otp.vendor ||
+	    !devinfo->otp.version)
+		return -EINVAL;
+
+	devinfo->otp.valid = true;
+	return 0;
+}
+
+static int
+brcmf_pcie_parse_otp(struct brcmf_pciedev_info *devinfo, u8 *otp, size_t size)
+{
+	int p = 0;
+	int ret = -1;
+
+	brcmf_dbg(PCIE, "parse_otp size=%ld\n", size);
+
+	while (p < (size - 1)) {
+		u8 type = otp[p];
+		u8 length = otp[p + 1];
+
+		if (type == 0)
+			break;
+
+		if ((p + 2 + length) > size)
+			break;
+
+		switch (type) {
+		case BRCMF_OTP_SYS_VENDOR:
+			brcmf_dbg(PCIE, "OTP @ 0x%x (0x%x): SYS_VENDOR\n",
+				  p, length);
+			ret = brcmf_pcie_parse_otp_sys_vendor(devinfo,
+							      &otp[p + 2],
+							      length);
+			break;
+		case BRCMF_OTP_BRCM_CIS:
+			brcmf_dbg(PCIE, "OTP @ 0x%x (0x%x): BRCM_CIS\n",
+				  p, length);
+			break;
+		default:
+			brcmf_dbg(PCIE, "OTP @ 0x%x (0x%x): Unknown type 0x%x\n",
+				  p, length, type);
+			break;
+		}
+
+		p += 2 + length;
+	}
+
+	return ret;
+}
+
+static int brcmf_pcie_read_otp(struct brcmf_pciedev_info *devinfo)
+{
+	const struct pci_dev *pdev = devinfo->pdev;
+	struct brcmf_bus *bus = dev_get_drvdata(&pdev->dev);
+	u32 coreid, base, words, idx, sromctl;
+	u16 *otp;
+	struct brcmf_core *core;
+	int ret;
+
+	switch (devinfo->ci->chip) {
+	default:
+		/* OTP not supported on this chip */
+		return 0;
+	}
+
+	core = brcmf_chip_get_core(devinfo->ci, coreid);
+	if (!core) {
+		brcmf_err(bus, "No OTP core\n");
+		return -ENODEV;
+	}
+
+	if (coreid == BCMA_CORE_CHIPCOMMON) {
+		/* Chips with OTP accessed via ChipCommon need additional
+		 * handling to access the OTP
+		 */
+		brcmf_pcie_select_core(devinfo, coreid);
+		sromctl = READCC32(devinfo, sromcontrol);
+
+		if (!(sromctl & BCMA_CC_SROM_CONTROL_OTP_PRESENT)) {
+			/* Chip lacks OTP, try without it... */
+			brcmf_err(bus,
+				  "OTP unavailable, using default firmware\n");
+			return 0;
+		}
+
+		/* Map OTP to shadow area */
+		WRITECC32(devinfo, sromcontrol,
+			  sromctl | BCMA_CC_SROM_CONTROL_OTPSEL);
+	}
+
+	otp = kzalloc(sizeof(u16) * words, GFP_KERNEL);
+
+	/* Map bus window to SROM/OTP shadow area in core */
+	base = brcmf_pcie_buscore_prep_addr(devinfo->pdev, base + core->base);
+
+	brcmf_dbg(PCIE, "OTP data:\n");
+	for (idx = 0; idx < words; idx++) {
+		otp[idx] = brcmf_pcie_read_reg16(devinfo, base + 2 * idx);
+		brcmf_dbg(PCIE, "[%8x] 0x%04x\n", base + 2 * idx, otp[idx]);
+	}
+
+	if (coreid == BCMA_CORE_CHIPCOMMON) {
+		brcmf_pcie_select_core(devinfo, coreid);
+		WRITECC32(devinfo, sromcontrol, sromctl);
+	}
+
+	ret = brcmf_pcie_parse_otp(devinfo, (u8 *)otp, 2 * words);
+	kfree(otp);
+
+	return ret;
+}
+
 #define BRCMF_PCIE_FW_CODE	0
 #define BRCMF_PCIE_FW_NVRAM	1
 #define BRCMF_PCIE_FW_CLM	2
@@ -1958,6 +2171,12 @@  brcmf_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (ret)
 		goto fail_bus;
 
+	ret = brcmf_pcie_read_otp(devinfo);
+	if (ret) {
+		brcmf_err(bus, "failed to parse OTP\n");
+		goto fail_brcmf;
+	}
+
 	fwreq = brcmf_pcie_prepare_fw_request(devinfo);
 	if (!fwreq) {
 		ret = -ENOMEM;
diff --git a/include/linux/bcma/bcma_driver_chipcommon.h b/include/linux/bcma/bcma_driver_chipcommon.h
index d35b9206096d..c91db7460190 100644
--- a/include/linux/bcma/bcma_driver_chipcommon.h
+++ b/include/linux/bcma/bcma_driver_chipcommon.h
@@ -270,6 +270,7 @@ 
 #define  BCMA_CC_SROM_CONTROL_OP_WRDIS	0x40000000
 #define  BCMA_CC_SROM_CONTROL_OP_WREN	0x60000000
 #define  BCMA_CC_SROM_CONTROL_OTPSEL	0x00000010
+#define  BCMA_CC_SROM_CONTROL_OTP_PRESENT	0x00000020
 #define  BCMA_CC_SROM_CONTROL_LOCK	0x00000008
 #define  BCMA_CC_SROM_CONTROL_SIZE_MASK	0x00000006
 #define  BCMA_CC_SROM_CONTROL_SIZE_1K	0x00000000