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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/misc/eeprom/eeprom_93cx6.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/misc/eeprom/eeprom_93cx6.c')
-rw-r--r-- | drivers/misc/eeprom/eeprom_93cx6.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/drivers/misc/eeprom/eeprom_93cx6.c b/drivers/misc/eeprom/eeprom_93cx6.c new file mode 100644 index 000000000..9627294fe --- /dev/null +++ b/drivers/misc/eeprom/eeprom_93cx6.c @@ -0,0 +1,372 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2004 - 2006 rt2x00 SourceForge Project + * <http://rt2x00.serialmonkey.com> + * + * Module: eeprom_93cx6 + * Abstract: EEPROM reader routines for 93cx6 chipsets. + * Supported chipsets: 93c46 & 93c66. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/eeprom_93cx6.h> + +MODULE_AUTHOR("http://rt2x00.serialmonkey.com"); +MODULE_VERSION("1.0"); +MODULE_DESCRIPTION("EEPROM 93cx6 chip driver"); +MODULE_LICENSE("GPL"); + +static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom) +{ + eeprom->reg_data_clock = 1; + eeprom->register_write(eeprom); + + /* + * Add a short delay for the pulse to work. + * According to the specifications the "maximum minimum" + * time should be 450ns. + */ + ndelay(450); +} + +static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom) +{ + eeprom->reg_data_clock = 0; + eeprom->register_write(eeprom); + + /* + * Add a short delay for the pulse to work. + * According to the specifications the "maximum minimum" + * time should be 450ns. + */ + ndelay(450); +} + +static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom) +{ + /* + * Clear all flags, and enable chip select. + */ + eeprom->register_read(eeprom); + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + eeprom->reg_data_clock = 0; + eeprom->reg_chip_select = 1; + eeprom->drive_data = 1; + eeprom->register_write(eeprom); + + /* + * kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); +} + +static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom) +{ + /* + * Clear chip_select and data_in flags. + */ + eeprom->register_read(eeprom); + eeprom->reg_data_in = 0; + eeprom->reg_chip_select = 0; + eeprom->register_write(eeprom); + + /* + * kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); +} + +static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom, + const u16 data, const u16 count) +{ + unsigned int i; + + eeprom->register_read(eeprom); + + /* + * Clear data flags. + */ + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + eeprom->drive_data = 1; + + /* + * Start writing all bits. + */ + for (i = count; i > 0; i--) { + /* + * Check if this bit needs to be set. + */ + eeprom->reg_data_in = !!(data & (1 << (i - 1))); + + /* + * Write the bit to the eeprom register. + */ + eeprom->register_write(eeprom); + + /* + * Kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); + } + + eeprom->reg_data_in = 0; + eeprom->register_write(eeprom); +} + +static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom, + u16 *data, const u16 count) +{ + unsigned int i; + u16 buf = 0; + + eeprom->register_read(eeprom); + + /* + * Clear data flags. + */ + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + eeprom->drive_data = 0; + + /* + * Start reading all bits. + */ + for (i = count; i > 0; i--) { + eeprom_93cx6_pulse_high(eeprom); + + eeprom->register_read(eeprom); + + /* + * Clear data_in flag. + */ + eeprom->reg_data_in = 0; + + /* + * Read if the bit has been set. + */ + if (eeprom->reg_data_out) + buf |= (1 << (i - 1)); + + eeprom_93cx6_pulse_low(eeprom); + } + + *data = buf; +} + +/** + * eeprom_93cx6_read - Read a word from eeprom + * @eeprom: Pointer to eeprom structure + * @word: Word index from where we should start reading + * @data: target pointer where the information will have to be stored + * + * This function will read the eeprom data as host-endian word + * into the given data pointer. + */ +void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word, + u16 *data) +{ + u16 command; + + /* + * Initialize the eeprom register + */ + eeprom_93cx6_startup(eeprom); + + /* + * Select the read opcode and the word to be read. + */ + command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word; + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width); + + /* + * Read the requested 16 bits. + */ + eeprom_93cx6_read_bits(eeprom, data, 16); + + /* + * Cleanup eeprom register. + */ + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_read); + +/** + * eeprom_93cx6_multiread - Read multiple words from eeprom + * @eeprom: Pointer to eeprom structure + * @word: Word index from where we should start reading + * @data: target pointer where the information will have to be stored + * @words: Number of words that should be read. + * + * This function will read all requested words from the eeprom, + * this is done by calling eeprom_93cx6_read() multiple times. + * But with the additional change that while the eeprom_93cx6_read + * will return host ordered bytes, this method will return little + * endian words. + */ +void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word, + __le16 *data, const u16 words) +{ + unsigned int i; + u16 tmp; + + for (i = 0; i < words; i++) { + tmp = 0; + eeprom_93cx6_read(eeprom, word + i, &tmp); + data[i] = cpu_to_le16(tmp); + } +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread); + +/** + * eeprom_93cx6_readb - Read a byte from eeprom + * @eeprom: Pointer to eeprom structure + * @byte: Byte index from where we should start reading + * @data: target pointer where the information will have to be stored + * + * This function will read a byte of the eeprom data + * into the given data pointer. + */ +void eeprom_93cx6_readb(struct eeprom_93cx6 *eeprom, const u8 byte, + u8 *data) +{ + u16 command; + u16 tmp; + + /* + * Initialize the eeprom register + */ + eeprom_93cx6_startup(eeprom); + + /* + * Select the read opcode and the byte to be read. + */ + command = (PCI_EEPROM_READ_OPCODE << (eeprom->width + 1)) | byte; + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width + 1); + + /* + * Read the requested 8 bits. + */ + eeprom_93cx6_read_bits(eeprom, &tmp, 8); + *data = tmp & 0xff; + + /* + * Cleanup eeprom register. + */ + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_readb); + +/** + * eeprom_93cx6_multireadb - Read multiple bytes from eeprom + * @eeprom: Pointer to eeprom structure + * @byte: Index from where we should start reading + * @data: target pointer where the information will have to be stored + * @bytes: Number of bytes that should be read. + * + * This function will read all requested bytes from the eeprom, + * this is done by calling eeprom_93cx6_readb() multiple times. + */ +void eeprom_93cx6_multireadb(struct eeprom_93cx6 *eeprom, const u8 byte, + u8 *data, const u16 bytes) +{ + unsigned int i; + + for (i = 0; i < bytes; i++) + eeprom_93cx6_readb(eeprom, byte + i, &data[i]); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_multireadb); + +/** + * eeprom_93cx6_wren - set the write enable state + * @eeprom: Pointer to eeprom structure + * @enable: true to enable writes, otherwise disable writes + * + * Set the EEPROM write enable state to either allow or deny + * writes depending on the @enable value. + */ +void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable) +{ + u16 command; + + /* start the command */ + eeprom_93cx6_startup(eeprom); + + /* create command to enable/disable */ + + command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE; + command <<= (eeprom->width - 2); + + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width); + + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_wren); + +/** + * eeprom_93cx6_write - write data to the EEPROM + * @eeprom: Pointer to eeprom structure + * @addr: Address to write data to. + * @data: The data to write to address @addr. + * + * Write the @data to the specified @addr in the EEPROM and + * waiting for the device to finish writing. + * + * Note, since we do not expect large number of write operations + * we delay in between parts of the operation to avoid using excessive + * amounts of CPU time busy waiting. + */ +void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data) +{ + int timeout = 100; + u16 command; + + /* start the command */ + eeprom_93cx6_startup(eeprom); + + command = PCI_EEPROM_WRITE_OPCODE << eeprom->width; + command |= addr; + + /* send write command */ + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width); + + /* send data */ + eeprom_93cx6_write_bits(eeprom, data, 16); + + /* get ready to check for busy */ + eeprom->drive_data = 0; + eeprom->reg_chip_select = 1; + eeprom->register_write(eeprom); + + /* wait at-least 250ns to get DO to be the busy signal */ + usleep_range(1000, 2000); + + /* wait for DO to go high to signify finish */ + + while (true) { + eeprom->register_read(eeprom); + + if (eeprom->reg_data_out) + break; + + usleep_range(1000, 2000); + + if (--timeout <= 0) { + printk(KERN_ERR "%s: timeout\n", __func__); + break; + } + } + + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_write); |