--- /dev/null
+/*
+ * Copyright (C) 2004 - 2006 rt2x00 SourceForge Project
+ * <http://rt2x00.serialmonkey.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * 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
+ * @word: 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
+ * @words: 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);
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