On Fri, Jun 11, 2021 at 07:26:49AM +0200, Jiri Prchal wrote:
> Added support for Cypress FRAMs.
Which devices exactly are you adding support for?
> These frams have ID and some of them have serial number too.
> Size of them is recognized by ID. They don't have pages, it could
> be read or written at once, but it's limited in this driver to
> io limit 4096.
>
> Signed-off-by: Jiri Prchal <jiri.prchal@xxxxxxxxxxx>
> ---
> v2: fixed warning at %zd at int
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> v3: resend and added more recipients
> v4: resend
> v5: used in-kernel function int_pow
> v6: no change here
> v7: moved definition of sernum size to patch 4
> v8: changed buffer type to u8
> v9: removed needless has_sernum
> ---
> drivers/misc/eeprom/Kconfig | 5 +-
> drivers/misc/eeprom/at25.c | 134 ++++++++++++++++++++++++++++--------
> 2 files changed, 107 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig
> index 0f791bfdc1f5..f0a7531f354c 100644
> --- a/drivers/misc/eeprom/Kconfig
> +++ b/drivers/misc/eeprom/Kconfig
> @@ -32,12 +32,13 @@ config EEPROM_AT24
> will be called at24.
>
> config EEPROM_AT25
> - tristate "SPI EEPROMs from most vendors"
> + tristate "SPI EEPROMs (FRAMs) from most vendors"
> depends on SPI && SYSFS
> select NVMEM
> select NVMEM_SYSFS
> help
> - Enable this driver to get read/write support to most SPI EEPROMs,
> + Enable this driver to get read/write support to most SPI EEPROMs
> + and Cypress FRAMs,
> after you configure the board init code to know about each eeprom
> on your target board.
>
> diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
> index b76e4901b4a4..e59b6852816d 100644
> --- a/drivers/misc/eeprom/at25.c
> +++ b/drivers/misc/eeprom/at25.c
> @@ -1,6 +1,7 @@
> // SPDX-License-Identifier: GPL-2.0-or-later
> /*
> * at25.c -- support most SPI EEPROMs, such as Atmel AT25 models
> + * and Cypress FRAMs FM25 models
> *
> * Copyright (C) 2006 David Brownell
> */
> @@ -16,6 +17,9 @@
> #include <linux/spi/spi.h>
> #include <linux/spi/eeprom.h>
> #include <linux/property.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/math.h>
>
> /*
> * NOTE: this is an *EEPROM* driver. The vagaries of product naming
> @@ -42,6 +46,9 @@ struct at25_data {
> #define AT25_WRSR 0x01 /* write status register */
> #define AT25_READ 0x03 /* read byte(s) */
> #define AT25_WRITE 0x02 /* write byte(s)/sector */
> +#define FM25_SLEEP 0xb9 /* enter sleep mode */
> +#define FM25_RDID 0x9f /* read device ID */
> +#define FM25_RDSN 0xc3 /* read S/N */
>
> #define AT25_SR_nRDY 0x01 /* nRDY = write-in-progress */
> #define AT25_SR_WEN 0x02 /* write enable (latched) */
> @@ -51,6 +58,8 @@ struct at25_data {
>
> #define AT25_INSTR_BIT3 0x08 /* Additional address bit in instr */
>
> +#define FM25_ID_LEN 9 /* ID length */
> +
> #define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */
>
> /* Specs often allow 5 msec for a page write, sometimes 20 msec;
> @@ -58,6 +67,9 @@ struct at25_data {
> */
> #define EE_TIMEOUT 25
>
> +#define IS_EEPROM 0
> +#define IS_FRAM 1
> +
> /*-------------------------------------------------------------------------*/
>
> #define io_limit PAGE_SIZE /* bytes */
> @@ -129,6 +141,36 @@ static int at25_ee_read(void *priv, unsigned int offset,
> return status;
> }
>
> +/*
> + * read extra registers as ID or serial number
> + */
> +static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command,
> + int len)
> +{
> + int status;
> + struct spi_transfer t[2];
> + struct spi_message m;
> +
> + spi_message_init(&m);
> + memset(t, 0, sizeof(t));
> +
> + t[0].tx_buf = &command;
> + t[0].len = 1;
> + spi_message_add_tail(&t[0], &m);
> +
> + t[1].rx_buf = buf;
> + t[1].len = len;
> + spi_message_add_tail(&t[1], &m);
> +
> + mutex_lock(&at25->lock);
> +
> + status = spi_sync(at25->spi, &m);
> + dev_dbg(&at25->spi->dev, "read %d aux bytes --> %d\n", len, status);
> +
> + mutex_unlock(&at25->lock);
> + return status;
> +}
> +
> static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
> {
> struct at25_data *at25 = priv;
> @@ -303,34 +345,37 @@ static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
> return 0;
> }
>
> +static const struct of_device_id at25_of_match[] = {
> + { .compatible = "atmel,at25", .data = (const void *)IS_EEPROM },
> + { .compatible = "cypress,fm25", .data = (const void *)IS_FRAM },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, at25_of_match);
> +
> static int at25_probe(struct spi_device *spi)
> {
> struct at25_data *at25 = NULL;
> struct spi_eeprom chip;
> int err;
> int sr;
> - int addrlen;
> + u8 id[FM25_ID_LEN];
> + const struct of_device_id *match;
> + int is_fram = 0;
> +
> + match = of_match_device(of_match_ptr(at25_of_match), &spi->dev);
> + if (match)
> + is_fram = (int)(uintptr_t)match->data;
Why the double cast?
And "uintptr_t" is not a kernel type. This originally is just a void *,
so no need to "double cast" it here, right?
thanks,
greg k-h
