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409 lines
10 KiB
409 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* ------------------------------------------------------------------------ * |
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* i2c-parport.c I2C bus over parallel port * |
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* ------------------------------------------------------------------------ * |
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Copyright (C) 2003-2011 Jean Delvare <[email protected]> |
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Based on older i2c-philips-par.c driver |
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Copyright (C) 1995-2000 Simon G. Vogl |
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With some changes from: |
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Frodo Looijaard <[email protected]> |
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Kyösti Mälkki <[email protected]> |
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* ------------------------------------------------------------------------ */ |
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#define pr_fmt(fmt) "i2c-parport: " fmt |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/delay.h> |
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#include <linux/parport.h> |
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#include <linux/i2c.h> |
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#include <linux/i2c-algo-bit.h> |
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#include <linux/i2c-smbus.h> |
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#include <linux/slab.h> |
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#include <linux/list.h> |
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#include <linux/mutex.h> |
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#define PORT_DATA 0 |
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#define PORT_STAT 1 |
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#define PORT_CTRL 2 |
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struct lineop { |
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u8 val; |
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u8 port; |
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u8 inverted; |
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}; |
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struct adapter_parm { |
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struct lineop setsda; |
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struct lineop setscl; |
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struct lineop getsda; |
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struct lineop getscl; |
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struct lineop init; |
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unsigned int smbus_alert:1; |
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}; |
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static const struct adapter_parm adapter_parm[] = { |
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/* type 0: Philips adapter */ |
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{ |
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.setsda = { 0x80, PORT_DATA, 1 }, |
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.setscl = { 0x08, PORT_CTRL, 0 }, |
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.getsda = { 0x80, PORT_STAT, 0 }, |
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.getscl = { 0x08, PORT_STAT, 0 }, |
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}, |
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/* type 1: home brew teletext adapter */ |
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{ |
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.setsda = { 0x02, PORT_DATA, 0 }, |
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.setscl = { 0x01, PORT_DATA, 0 }, |
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.getsda = { 0x80, PORT_STAT, 1 }, |
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}, |
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/* type 2: Velleman K8000 adapter */ |
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{ |
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.setsda = { 0x02, PORT_CTRL, 1 }, |
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.setscl = { 0x08, PORT_CTRL, 1 }, |
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.getsda = { 0x10, PORT_STAT, 0 }, |
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}, |
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/* type 3: ELV adapter */ |
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{ |
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.setsda = { 0x02, PORT_DATA, 1 }, |
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.setscl = { 0x01, PORT_DATA, 1 }, |
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.getsda = { 0x40, PORT_STAT, 1 }, |
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.getscl = { 0x08, PORT_STAT, 1 }, |
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}, |
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/* type 4: ADM1032 evaluation board */ |
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{ |
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.setsda = { 0x02, PORT_DATA, 1 }, |
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.setscl = { 0x01, PORT_DATA, 1 }, |
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.getsda = { 0x10, PORT_STAT, 1 }, |
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.init = { 0xf0, PORT_DATA, 0 }, |
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.smbus_alert = 1, |
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}, |
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/* type 5: ADM1025, ADM1030 and ADM1031 evaluation boards */ |
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{ |
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.setsda = { 0x02, PORT_DATA, 1 }, |
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.setscl = { 0x01, PORT_DATA, 1 }, |
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.getsda = { 0x10, PORT_STAT, 1 }, |
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}, |
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/* type 6: Barco LPT->DVI (K5800236) adapter */ |
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{ |
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.setsda = { 0x02, PORT_DATA, 1 }, |
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.setscl = { 0x01, PORT_DATA, 1 }, |
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.getsda = { 0x20, PORT_STAT, 0 }, |
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.getscl = { 0x40, PORT_STAT, 0 }, |
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.init = { 0xfc, PORT_DATA, 0 }, |
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}, |
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/* type 7: One For All JP1 parallel port adapter */ |
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{ |
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.setsda = { 0x01, PORT_DATA, 0 }, |
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.setscl = { 0x02, PORT_DATA, 0 }, |
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.getsda = { 0x80, PORT_STAT, 1 }, |
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.init = { 0x04, PORT_DATA, 1 }, |
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}, |
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/* type 8: VCT-jig */ |
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{ |
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.setsda = { 0x04, PORT_DATA, 1 }, |
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.setscl = { 0x01, PORT_DATA, 1 }, |
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.getsda = { 0x40, PORT_STAT, 0 }, |
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.getscl = { 0x80, PORT_STAT, 1 }, |
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}, |
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}; |
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/* ----- Device list ------------------------------------------------------ */ |
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struct i2c_par { |
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struct pardevice *pdev; |
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struct i2c_adapter adapter; |
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struct i2c_algo_bit_data algo_data; |
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struct i2c_smbus_alert_setup alert_data; |
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struct i2c_client *ara; |
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struct list_head node; |
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}; |
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static LIST_HEAD(adapter_list); |
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static DEFINE_MUTEX(adapter_list_lock); |
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#define MAX_DEVICE 4 |
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static int parport[MAX_DEVICE] = {0, -1, -1, -1}; |
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module_param_array(parport, int, NULL, 0); |
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MODULE_PARM_DESC(parport, |
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"List of parallel ports to bind to, by index.\n" |
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" At most " __stringify(MAX_DEVICE) " devices are supported.\n" |
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" Default is one device connected to parport0.\n" |
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); |
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static int type = -1; |
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module_param(type, int, 0); |
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MODULE_PARM_DESC(type, |
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"Type of adapter:\n" |
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" 0 = Philips adapter\n" |
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" 1 = home brew teletext adapter\n" |
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" 2 = Velleman K8000 adapter\n" |
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" 3 = ELV adapter\n" |
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" 4 = ADM1032 evaluation board\n" |
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" 5 = ADM1025, ADM1030 and ADM1031 evaluation boards\n" |
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" 6 = Barco LPT->DVI (K5800236) adapter\n" |
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" 7 = One For All JP1 parallel port adapter\n" |
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" 8 = VCT-jig\n" |
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); |
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/* ----- Low-level parallel port access ----------------------------------- */ |
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static void port_write_data(struct parport *p, unsigned char d) |
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{ |
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parport_write_data(p, d); |
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} |
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static void port_write_control(struct parport *p, unsigned char d) |
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{ |
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parport_write_control(p, d); |
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} |
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static unsigned char port_read_data(struct parport *p) |
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{ |
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return parport_read_data(p); |
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} |
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static unsigned char port_read_status(struct parport *p) |
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{ |
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return parport_read_status(p); |
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} |
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static unsigned char port_read_control(struct parport *p) |
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{ |
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return parport_read_control(p); |
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} |
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static void (* const port_write[])(struct parport *, unsigned char) = { |
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port_write_data, |
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NULL, |
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port_write_control, |
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}; |
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static unsigned char (* const port_read[])(struct parport *) = { |
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port_read_data, |
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port_read_status, |
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port_read_control, |
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}; |
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/* ----- Unified line operation functions --------------------------------- */ |
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static inline void line_set(struct parport *data, int state, |
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const struct lineop *op) |
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{ |
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u8 oldval = port_read[op->port](data); |
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/* Touch only the bit(s) needed */ |
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if ((op->inverted && !state) || (!op->inverted && state)) |
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port_write[op->port](data, oldval | op->val); |
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else |
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port_write[op->port](data, oldval & ~op->val); |
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} |
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static inline int line_get(struct parport *data, |
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const struct lineop *op) |
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{ |
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u8 oldval = port_read[op->port](data); |
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return ((op->inverted && (oldval & op->val) != op->val) |
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|| (!op->inverted && (oldval & op->val) == op->val)); |
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} |
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/* ----- I2C algorithm call-back functions and structures ----------------- */ |
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static void parport_setscl(void *data, int state) |
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{ |
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line_set((struct parport *) data, state, &adapter_parm[type].setscl); |
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} |
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static void parport_setsda(void *data, int state) |
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{ |
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line_set((struct parport *) data, state, &adapter_parm[type].setsda); |
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} |
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static int parport_getscl(void *data) |
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{ |
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return line_get((struct parport *) data, &adapter_parm[type].getscl); |
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} |
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static int parport_getsda(void *data) |
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{ |
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return line_get((struct parport *) data, &adapter_parm[type].getsda); |
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} |
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/* Encapsulate the functions above in the correct structure. |
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Note that this is only a template, from which the real structures are |
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copied. The attaching code will set getscl to NULL for adapters that |
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cannot read SCL back, and will also make the data field point to |
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the parallel port structure. */ |
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static const struct i2c_algo_bit_data parport_algo_data = { |
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.setsda = parport_setsda, |
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.setscl = parport_setscl, |
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.getsda = parport_getsda, |
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.getscl = parport_getscl, |
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.udelay = 10, /* ~50 kbps */ |
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.timeout = HZ, |
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}; |
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/* ----- I2c and parallel port call-back functions and structures --------- */ |
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static void i2c_parport_irq(void *data) |
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{ |
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struct i2c_par *adapter = data; |
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struct i2c_client *ara = adapter->ara; |
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if (ara) { |
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dev_dbg(&ara->dev, "SMBus alert received\n"); |
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i2c_handle_smbus_alert(ara); |
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} else |
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dev_dbg(&adapter->adapter.dev, |
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"SMBus alert received but no ARA client!\n"); |
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} |
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static void i2c_parport_attach(struct parport *port) |
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{ |
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struct i2c_par *adapter; |
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int i; |
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struct pardev_cb i2c_parport_cb; |
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if (type < 0) { |
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pr_warn("adapter type unspecified\n"); |
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return; |
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} |
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if (type >= ARRAY_SIZE(adapter_parm)) { |
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pr_warn("invalid type (%d)\n", type); |
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return; |
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} |
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for (i = 0; i < MAX_DEVICE; i++) { |
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if (parport[i] == -1) |
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continue; |
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if (port->number == parport[i]) |
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break; |
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} |
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if (i == MAX_DEVICE) { |
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pr_debug("Not using parport%d.\n", port->number); |
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return; |
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} |
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adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL); |
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if (!adapter) |
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return; |
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memset(&i2c_parport_cb, 0, sizeof(i2c_parport_cb)); |
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i2c_parport_cb.flags = PARPORT_FLAG_EXCL; |
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i2c_parport_cb.irq_func = i2c_parport_irq; |
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i2c_parport_cb.private = adapter; |
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pr_debug("attaching to %s\n", port->name); |
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parport_disable_irq(port); |
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adapter->pdev = parport_register_dev_model(port, "i2c-parport", |
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&i2c_parport_cb, i); |
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if (!adapter->pdev) { |
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pr_err("Unable to register with parport\n"); |
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goto err_free; |
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} |
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/* Fill the rest of the structure */ |
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adapter->adapter.owner = THIS_MODULE; |
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adapter->adapter.class = I2C_CLASS_HWMON; |
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strlcpy(adapter->adapter.name, "Parallel port adapter", |
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sizeof(adapter->adapter.name)); |
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adapter->algo_data = parport_algo_data; |
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/* Slow down if we can't sense SCL */ |
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if (!adapter_parm[type].getscl.val) { |
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adapter->algo_data.getscl = NULL; |
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adapter->algo_data.udelay = 50; /* ~10 kbps */ |
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} |
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adapter->algo_data.data = port; |
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adapter->adapter.algo_data = &adapter->algo_data; |
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adapter->adapter.dev.parent = port->physport->dev; |
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if (parport_claim_or_block(adapter->pdev) < 0) { |
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dev_err(&adapter->pdev->dev, |
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"Could not claim parallel port\n"); |
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goto err_unregister; |
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} |
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/* Reset hardware to a sane state (SCL and SDA high) */ |
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parport_setsda(port, 1); |
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parport_setscl(port, 1); |
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/* Other init if needed (power on...) */ |
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if (adapter_parm[type].init.val) { |
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line_set(port, 1, &adapter_parm[type].init); |
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/* Give powered devices some time to settle */ |
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msleep(100); |
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} |
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if (i2c_bit_add_bus(&adapter->adapter) < 0) { |
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dev_err(&adapter->pdev->dev, "Unable to register with I2C\n"); |
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goto err_unregister; |
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} |
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/* Setup SMBus alert if supported */ |
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if (adapter_parm[type].smbus_alert) { |
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struct i2c_client *ara; |
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ara = i2c_new_smbus_alert_device(&adapter->adapter, |
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&adapter->alert_data); |
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if (!IS_ERR(ara)) { |
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adapter->ara = ara; |
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parport_enable_irq(port); |
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} else { |
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dev_warn(&adapter->pdev->dev, |
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"Failed to register ARA client\n"); |
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} |
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} |
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/* Add the new adapter to the list */ |
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mutex_lock(&adapter_list_lock); |
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list_add_tail(&adapter->node, &adapter_list); |
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mutex_unlock(&adapter_list_lock); |
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return; |
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err_unregister: |
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parport_release(adapter->pdev); |
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parport_unregister_device(adapter->pdev); |
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err_free: |
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kfree(adapter); |
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} |
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static void i2c_parport_detach(struct parport *port) |
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{ |
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struct i2c_par *adapter, *_n; |
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/* Walk the list */ |
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mutex_lock(&adapter_list_lock); |
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list_for_each_entry_safe(adapter, _n, &adapter_list, node) { |
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if (adapter->pdev->port == port) { |
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if (adapter->ara) { |
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parport_disable_irq(port); |
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i2c_unregister_device(adapter->ara); |
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} |
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i2c_del_adapter(&adapter->adapter); |
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/* Un-init if needed (power off...) */ |
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if (adapter_parm[type].init.val) |
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line_set(port, 0, &adapter_parm[type].init); |
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parport_release(adapter->pdev); |
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parport_unregister_device(adapter->pdev); |
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list_del(&adapter->node); |
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kfree(adapter); |
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} |
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} |
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mutex_unlock(&adapter_list_lock); |
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} |
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static struct parport_driver i2c_parport_driver = { |
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.name = "i2c-parport", |
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.match_port = i2c_parport_attach, |
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.detach = i2c_parport_detach, |
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.devmodel = true, |
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}; |
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module_parport_driver(i2c_parport_driver); |
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MODULE_AUTHOR("Jean Delvare <[email protected]>"); |
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MODULE_DESCRIPTION("I2C bus over parallel port"); |
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MODULE_LICENSE("GPL");
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