Re: [PATCH 2/3] common: board: phytec: import SoM detection for imx8m based SoM from u-boot

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 06.06.23 12:50, Marc Kleine-Budde wrote:
> This patch imports and cleans up the SoM detection for imx8n based SoM
> from u-boot.
> 
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  common/boards/Kconfig                             |   7 +
>  common/boards/Makefile                            |   1 +
>  common/boards/phytec/Makefile                     |   4 +
>  common/boards/phytec/phytec-som-detection.c       | 209 ++++++++++++++++++++++
>  common/boards/phytec/phytec-som-imx8m-detection.c | 151 ++++++++++++++++
>  include/phytec-som-detection.h                    |  69 +++++++
>  include/phytec-som-imx8m-detection.h              |  19 ++
>  7 files changed, 460 insertions(+)
> 
> diff --git a/common/boards/Kconfig b/common/boards/Kconfig
> index e27273b7671d..b240548b484d 100644
> --- a/common/boards/Kconfig
> +++ b/common/boards/Kconfig
> @@ -2,3 +2,10 @@
>  
>  config BOARD_QEMU_VIRT
>  	bool
> +
> +config BOARD_PHYTEC_SOM_DETECTION
> +	bool
> +
> +config BOARD_PHYTEC_SOM_IMX8M_DETECTION
> +	bool
> +	select BOARD_PHYTEC_SOM_DETECTION
> diff --git a/common/boards/Makefile b/common/boards/Makefile
> index 5b4e429c13e9..2a96ce6aec5c 100644
> --- a/common/boards/Makefile
> +++ b/common/boards/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  
>  obj-$(CONFIG_BOARD_QEMU_VIRT)	+= qemu-virt/
> +obj-y += phytec/
> diff --git a/common/boards/phytec/Makefile b/common/boards/phytec/Makefile
> new file mode 100644
> index 000000000000..741a0e2eb704
> --- /dev/null
> +++ b/common/boards/phytec/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +lwl-$(CONFIG_BOARD_PHYTEC_SOM_DETECTION) += phytec-som-detection.o
> +lwl-$(CONFIG_BOARD_PHYTEC_SOM_IMX8M_DETECTION) += phytec-som-imx8m-detection.o
> diff --git a/common/boards/phytec/phytec-som-detection.c b/common/boards/phytec/phytec-som-detection.c
> new file mode 100644
> index 000000000000..d9479f8ced69
> --- /dev/null
> +++ b/common/boards/phytec/phytec-som-detection.c
> @@ -0,0 +1,209 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2020 PHYTEC Messtechnik GmbH
> + * Author: Teresa Remmet <t.remmet@phytec.de>
> + */
> +
> +#include <common.h>
> +#include <pbl/eeprom.h>
> +#include <phytec-som-imx8m-detection.h>
> +
> +struct phytec_eeprom_data eeprom_data;
> +
> +#define POLY (0x1070U << 3)
> +
> +static u8 _crc8(u16 data)
> +{
> +	int i;
> +
> +	for (i = 0; i < 8; i++) {
> +		if (data & 0x8000)
> +			data = data ^ POLY;
> +		data = data << 1;
> +	}
> +
> +	return data >> 8;
> +}
> +
> +static unsigned int crc8(unsigned int crc, const u8 *vptr, int len)
> +{
> +	int i;
> +
> +	for (i = 0; i < len; i++)
> +		crc = _crc8((crc ^ vptr[i]) << 8);
> +
> +	return crc;
> +}

There's already a crc8 implementation. Why can't you reuse it?

> +
> +char *phytec_get_opt(struct phytec_eeprom_data *data)

const return and const argument?

> +{
> +	char *opt;
> +
> +	if (!data)
> +		data = &eeprom_data;
> +
> +	switch (data->api_rev) {
> +	case PHYTEC_API_REV0:
> +	case PHYTEC_API_REV1:
> +		opt = data->data.data_api0.opt;
> +		break;
> +	case PHYTEC_API_REV2:
> +		opt = data->data.data_api2.opt;
> +		break;
> +	default:
> +		opt = NULL;
> +		break;
> +	};
> +
> +	return opt;
> +}
> +
> +static int phytec_eeprom_data_init(struct pbl_i2c *i2c,
> +				   struct phytec_eeprom_data *data,
> +				   int addr, u8 phytec_som_type)
> +{
> +	unsigned int crc;
> +	char *opt;
> +	int *ptr;
> +	int ret = -1, i;
> +	u8 som;
> +
> +	if (!data)
> +		data = &eeprom_data;
> +
> +	eeprom_read(i2c, addr, I2C_ADDR_16_BIT, data, sizeof(struct phytec_eeprom_data));
> +
> +	if (data->api_rev == 0xff) {
> +		pr_err("%s: EEPROM is not flashed. Prototype?\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0, ptr = (int *)data;
> +	     i < sizeof(struct phytec_eeprom_data);
> +	     i += sizeof(ptr), ptr++)
> +		if (*ptr != 0x0)
> +			break;
> +
> +	if (i == sizeof(struct phytec_eeprom_data)) {
> +		pr_err("%s: EEPROM data is all zero. Erased?\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	if (data->api_rev > PHYTEC_API_REV2) {
> +		pr_err("%s: EEPROM API revision %u not supported\n",
> +		       __func__, data->api_rev);
> +		return -EINVAL;
> +	}
> +
> +	/* We are done here for early revisions */
> +	if (data->api_rev <= PHYTEC_API_REV1)
> +		return 0;
> +
> +	crc = crc8(0, (const unsigned char *)data,
> +		   sizeof(struct phytec_eeprom_data));
> +	pr_debug("%s: crc: %x\n", __func__, crc);
> +
> +	if (crc) {
> +		pr_err("%s: CRC mismatch. EEPROM data is not usable\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	som = data->data.data_api2.som_no;
> +	pr_debug("%s: som id: %u\n", __func__, som);
> +	opt = phytec_get_opt(data);
> +	if (!opt)
> +		return -EINVAL;
> +
> +	if (IS_ENABLED(CONFIG_BOARD_PHYTEC_SOM_IMX8M_DETECTION))

Why is this behind CONFIG_ symbol?

> +		ret = phytec_imx8m_detect(som, opt, phytec_som_type);
> +
> +	if (ret) {
> +		pr_err("%s: SoM ID does not match. Wrong EEPROM data?\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +void phytec_print_som_info(struct phytec_eeprom_data *data)

const?

> +{
> +	struct phytec_api2_data *api2;
> +	char pcb_sub_rev;
> +	unsigned int ksp_no, sub_som_type1 = -1, sub_som_type2 = -1;
> +
> +	if (!data)
> +		data = &eeprom_data;
> +
> +	if (data->api_rev < PHYTEC_API_REV2)
> +		return;
> +
> +	api2 = &data->data.data_api2;
> +
> +	/* Calculate PCB subrevision */
> +	pcb_sub_rev = api2->pcb_sub_opt_rev & 0x0f;
> +	pcb_sub_rev = pcb_sub_rev ? ((pcb_sub_rev - 1) + 'a') : ' ';
> +
> +	/* print standard product string */
> +	if (api2->som_type <= 1) {
> +		pr_info("SoM: %s-%03u-%s.%s PCB rev: %u%c\n",
> +			phytec_som_type_str[api2->som_type], api2->som_no,
> +			api2->opt, api2->bom_rev, api2->pcb_rev, pcb_sub_rev);
> +		return;
> +	}
> +	/* print KSP/KSM string */
> +	if (api2->som_type <= 3) {
> +		ksp_no = (api2->ksp_no << 8) | api2->som_no;
> +		pr_info("SoM: %s-%u ",
> +			phytec_som_type_str[api2->som_type], ksp_no);
> +		/* print standard product based KSP/KSM strings */
> +	} else {
> +		switch (api2->som_type) {
> +		case 4:
> +			sub_som_type1 = 0;
> +			sub_som_type2 = 3;
> +			break;
> +		case 5:
> +			sub_som_type1 = 0;
> +			sub_som_type2 = 2;
> +			break;
> +		case 6:
> +			sub_som_type1 = 1;
> +			sub_som_type2 = 3;
> +			break;
> +		case 7:
> +			sub_som_type1 = 1;
> +			sub_som_type2 = 2;
> +			break;
> +		default:
> +			break;
> +		};
> +
> +		pr_info("SoM: %s-%03u-%s-%03u ",
> +			phytec_som_type_str[sub_som_type1],
> +			api2->som_no, phytec_som_type_str[sub_som_type2],
> +			api2->ksp_no);
> +	}
> +
> +	pr_cont("Option: %s BOM rev: %s PCB rev: %u%c\n", api2->opt,
> +		api2->bom_rev, api2->pcb_rev, pcb_sub_rev);

pr_cont doesn't work as you'd expect in barebox if you output to log.
Just do a separate print.

> +}
> +
> +int phytec_eeprom_data_setup(struct pbl_i2c *i2c, struct phytec_eeprom_data *data,
> +			     int addr, int addr_fallback, u8 cpu_type)
> +{
> +	int ret;
> +
> +	ret = phytec_eeprom_data_init(i2c, data, addr, cpu_type);
> +	if (ret) {
> +		pr_err("%s: init failed. Trying fall back address 0x%x\n",
> +		       __func__, addr_fallback);
> +		ret = phytec_eeprom_data_init(i2c, data, addr_fallback, cpu_type);
> +	}
> +
> +	if (ret)
> +		pr_err("%s: EEPROM data init failed\n", __func__);
> +	else
> +		pr_debug("%s: init successful\n", __func__);
> +
> +	return ret;
> +}
> diff --git a/common/boards/phytec/phytec-som-imx8m-detection.c b/common/boards/phytec/phytec-som-imx8m-detection.c
> new file mode 100644
> index 000000000000..cc7fb6971548
> --- /dev/null
> +++ b/common/boards/phytec/phytec-som-imx8m-detection.c
> @@ -0,0 +1,151 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2020 PHYTEC Messtechnik GmbH
> + * Author: Teresa Remmet <t.remmet@phytec.de>
> + */
> +
> +#include <common.h>
> +#include <mach/imx/generic.h>
> +#include <phytec-som-imx8m-detection.h>
> +
> +extern struct phytec_eeprom_data eeprom_data;
> +
> +/* Check if the SoM is actually one of the following products:
> + * - i.MX8MM
> + * - i.MX8MN
> + * - i.MX8MP
> + * - i.MX8MQ
> + *
> + * Returns 0 in case it's a known SoM. Otherwise, returns -errno.
> + */
> +u8 phytec_imx8m_detect(u8 som, char *opt, u8 cpu_type)

int. Even moreso as you're returning -EINVAL in the error case.

> +{
> +	if (som == PHYTEC_IMX8MP_SOM && cpu_type == IMX_CPU_IMX8MP)
> +		return 0;
> +
> +	if (som == PHYTEC_IMX8MM_SOM) {
> +		if (((opt[0] - '0') != 0) &&
> +		    ((opt[1] - '0') == 0) && cpu_type == IMX_CPU_IMX8MM)
> +			return 0;
> +		else if (((opt[0] - '0') == 0) &&
> +			 ((opt[1] - '0') != 0) && cpu_type == IMX_CPU_IMX8MN)
> +			return 0;
> +		return -EINVAL;
> +	}
> +
> +	if (som == PHYTEC_IMX8MQ_SOM && cpu_type == IMX_CPU_IMX8MQ)
> +		return 0;
> +
> +	return -EINVAL;
> +}
> +
> +/*
> + * So far all PHYTEC i.MX8M boards have RAM size definition at the
> + * same location.
> + */
> +u8 phytec_get_imx8m_ddr_size(struct phytec_eeprom_data *data)
> +{
> +	char *opt;
> +	u8 ddr_id;
> +
> +	if (!data)
> +		data = &eeprom_data;
> +
> +	opt = phytec_get_opt(data);
> +	if (opt)
> +		ddr_id = opt[2] - '0';
> +	else
> +		ddr_id = PHYTEC_EEPROM_INVAL;
> +
> +	pr_debug("%s: ddr id: %u\n", __func__, ddr_id);
> +
> +	return ddr_id;
> +}
> +
> +/*
> + * Filter SPI-NOR flash information. All i.MX8M boards have this at
> + * the same location.
> + * returns: 0x0 if no SPI is poulated. Otherwise a board depended

populated.

> + * code for the size. PHYTEC_EEPROM_INVAL when the data is invalid.
> + */
> +u8 phytec_get_imx8m_spi(struct phytec_eeprom_data *data)
> +{
> +	char *opt;
> +	u8 spi;
> +
> +	if (!data)
> +		data = &eeprom_data;
> +
> +	if (data->api_rev < PHYTEC_API_REV2)
> +		return PHYTEC_EEPROM_INVAL;
> +
> +	opt = phytec_get_opt(data);
> +	if (opt)
> +		spi = opt[4] - '0';
> +	else
> +		spi = PHYTEC_EEPROM_INVAL;

Why not return -EINVAL? If you want to handle 0xff
specially, just check for it and return -EINVAL.

> +
> +	pr_debug("%s: spi: %u\n", __func__, spi);

Do we really need this debug print? I think the debug print should rather
go into the future caller.

> +
> +	return spi;
> +}
> +
> +/*
> + * Filter ethernet phy information. All i.MX8M boards have this at
> + * the same location.
> + * returns: 0x0 if no ethernet phy is poulated. 0x1 if it is populated.
> + * PHYTEC_EEPROM_INVAL when the data is invalid.
> + */
> +u8 phytec_get_imx8m_eth(struct phytec_eeprom_data *data)
> +{
> +	char *opt;
> +	u8 eth;
> +
> +	if (!data)
> +		data = &eeprom_data;
> +
> +	if (data->api_rev < PHYTEC_API_REV2)
> +		return PHYTEC_EEPROM_INVAL;
> +
> +	opt = phytec_get_opt(data);
> +	if (opt) {
> +		eth = opt[5] - '0';
> +		eth &= 0x1;
> +	} else {
> +		eth = PHYTEC_EEPROM_INVAL;
> +	}
> +
> +	pr_debug("%s: eth: %u\n", __func__, eth);
> +
> +	return eth;
> +}
> +
> +/*
> + * Filter RTC information.
> + * returns: 0 if no RTC is poulated. 1 if it is populated.
> + * PHYTEC_EEPROM_INVAL when the data is invalid.
> + */
> +u8 phytec_get_imx8mp_rtc(struct phytec_eeprom_data *data)
> +{
> +	char *opt;
> +	u8 rtc;
> +
> +	if (!data)
> +		data = &eeprom_data;
> +
> +	if (data->api_rev < PHYTEC_API_REV2)
> +		return PHYTEC_EEPROM_INVAL;
> +
> +	opt = phytec_get_opt(data);
> +	if (opt) {
> +		rtc = opt[5] - '0';
> +		rtc &= 0x4;
> +		rtc = !(rtc >> 2);
> +	} else {
> +		rtc = PHYTEC_EEPROM_INVAL;
> +	}
> +
> +	pr_debug("%s: rtc: %u\n", __func__, rtc);
> +
> +	return rtc;
> +}
> diff --git a/include/phytec-som-detection.h b/include/phytec-som-detection.h
> new file mode 100644
> index 000000000000..65c7cb561e1d
> --- /dev/null
> +++ b/include/phytec-som-detection.h
> @@ -0,0 +1,69 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2020 PHYTEC Messtechnik GmbH
> + * Author: Teresa Remmet <t.remmet@phytec.de>
> + */
> +
> +#ifndef _PHYTEC_SOM_DETECTION_H
> +#define _PHYTEC_SOM_DETECTION_H
> +
> +#include <common.h>
> +#include <pbl/i2c.h>
> +
> +#define PHYTEC_MAX_OPTIONS	17
> +#define PHYTEC_IMX8MQ_SOM	66
> +#define PHYTEC_IMX8MM_SOM	69
> +#define PHYTEC_IMX8MP_SOM	70
> +
> +#define PHYTEC_EEPROM_INVAL	0xff
> +
> +enum {
> +	PHYTEC_API_REV0 = 0,
> +	PHYTEC_API_REV1,
> +	PHYTEC_API_REV2,
> +};
> +
> +static const char * const phytec_som_type_str[] = {
> +	"PCM",
> +	"PCL",
> +	"KSM",
> +	"KSP",
> +};
> +
> +struct phytec_api0_data {
> +	u8 pcb_rev;		/* PCB revision of SoM */
> +	u8 som_type;		/* SoM type */
> +	u8 ksp_no;		/* KSP no */
> +	char opt[16];		/* SoM options */
> +	u8 mac[6];		/* MAC address (optional) */
> +	u8 pad[5];		/* padding */

__pad

> +	u8 cksum;		/* checksum */
> +} __attribute__ ((__packed__));
> +
> +struct phytec_api2_data {
> +	u8 pcb_rev;		/* PCB revision of SoM */
> +	u8 pcb_sub_opt_rev;	/* PCB subrevision and opt revision */
> +	u8 som_type;		/* SoM type */
> +	u8 som_no;		/* SoM number */
> +	u8 ksp_no;		/* KSP information */
> +	char opt[PHYTEC_MAX_OPTIONS]; /* SoM options */
> +	char bom_rev[2];	/* BOM revision */
> +	u8 mac[6];		/* MAC address (optional) */
> +	u8 crc8;		/* checksum */
> +} __attribute__ ((__packed__));
> +
> +struct phytec_eeprom_data {
> +	u8 api_rev;
> +	union {
> +		struct phytec_api0_data data_api0;
> +		struct phytec_api2_data data_api2;
> +	} data;
> +} __attribute__ ((__packed__));
> +
> +char *phytec_get_opt(struct phytec_eeprom_data *data);
> +int phytec_eeprom_data_setup(struct pbl_i2c *i2c, struct phytec_eeprom_data *data,
> +			     int addr, int addr_fallback, u8 cpu_type);
> +
> +void phytec_print_som_info(struct phytec_eeprom_data *data);
> +
> +#endif /* _PHYTEC_SOM_DETECTION_H */
> diff --git a/include/phytec-som-imx8m-detection.h b/include/phytec-som-imx8m-detection.h
> new file mode 100644
> index 000000000000..108d40bb4030
> --- /dev/null
> +++ b/include/phytec-som-imx8m-detection.h

include/boards/phytec/som-imx8m-detection.h or similar.

> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2020 PHYTEC Messtechnik GmbH
> + * Author: Teresa Remmet <t.remmet@phytec.de>
> + */
> +
> +#ifndef _PHYTEC_SOM_IMX8M_DETECTION_H
> +#define _PHYTEC_SOM_IMX8M_DETECTION_H
> +
> +#include <common.h>
> +#include <phytec-som-detection.h>
> +
> +u8 phytec_imx8m_detect(u8 som, char *opt, u8 cpu_type);
> +u8 phytec_get_imx8m_ddr_size(struct phytec_eeprom_data *data);
> +u8 phytec_get_imx8mp_rtc(struct phytec_eeprom_data *data);
> +u8 phytec_get_imx8m_spi(struct phytec_eeprom_data *data);
> +u8 phytec_get_imx8m_eth(struct phytec_eeprom_data *data);
> +
> +#endif /* _PHYTEC_SOM_IMX8M_DETECTION_H */
> 

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