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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/i2c/busses/i2c-parport.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-parport.c')
-rw-r--r-- | drivers/i2c/busses/i2c-parport.c | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c new file mode 100644 index 000000000..0af86a542 --- /dev/null +++ b/drivers/i2c/busses/i2c-parport.c @@ -0,0 +1,409 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* ------------------------------------------------------------------------ * + * i2c-parport.c I2C bus over parallel port * + * ------------------------------------------------------------------------ * + Copyright (C) 2003-2011 Jean Delvare <jdelvare@suse.de> + + Based on older i2c-philips-par.c driver + Copyright (C) 1995-2000 Simon G. Vogl + With some changes from: + Frodo Looijaard <frodol@dds.nl> + Kyösti Mälkki <kmalkki@cc.hut.fi> + + * ------------------------------------------------------------------------ */ + +#define pr_fmt(fmt) "i2c-parport: " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/parport.h> +#include <linux/i2c.h> +#include <linux/i2c-algo-bit.h> +#include <linux/i2c-smbus.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/mutex.h> + +#define PORT_DATA 0 +#define PORT_STAT 1 +#define PORT_CTRL 2 + +struct lineop { + u8 val; + u8 port; + u8 inverted; +}; + +struct adapter_parm { + struct lineop setsda; + struct lineop setscl; + struct lineop getsda; + struct lineop getscl; + struct lineop init; + unsigned int smbus_alert:1; +}; + +static const struct adapter_parm adapter_parm[] = { + /* type 0: Philips adapter */ + { + .setsda = { 0x80, PORT_DATA, 1 }, + .setscl = { 0x08, PORT_CTRL, 0 }, + .getsda = { 0x80, PORT_STAT, 0 }, + .getscl = { 0x08, PORT_STAT, 0 }, + }, + /* type 1: home brew teletext adapter */ + { + .setsda = { 0x02, PORT_DATA, 0 }, + .setscl = { 0x01, PORT_DATA, 0 }, + .getsda = { 0x80, PORT_STAT, 1 }, + }, + /* type 2: Velleman K8000 adapter */ + { + .setsda = { 0x02, PORT_CTRL, 1 }, + .setscl = { 0x08, PORT_CTRL, 1 }, + .getsda = { 0x10, PORT_STAT, 0 }, + }, + /* type 3: ELV adapter */ + { + .setsda = { 0x02, PORT_DATA, 1 }, + .setscl = { 0x01, PORT_DATA, 1 }, + .getsda = { 0x40, PORT_STAT, 1 }, + .getscl = { 0x08, PORT_STAT, 1 }, + }, + /* type 4: ADM1032 evaluation board */ + { + .setsda = { 0x02, PORT_DATA, 1 }, + .setscl = { 0x01, PORT_DATA, 1 }, + .getsda = { 0x10, PORT_STAT, 1 }, + .init = { 0xf0, PORT_DATA, 0 }, + .smbus_alert = 1, + }, + /* type 5: ADM1025, ADM1030 and ADM1031 evaluation boards */ + { + .setsda = { 0x02, PORT_DATA, 1 }, + .setscl = { 0x01, PORT_DATA, 1 }, + .getsda = { 0x10, PORT_STAT, 1 }, + }, + /* type 6: Barco LPT->DVI (K5800236) adapter */ + { + .setsda = { 0x02, PORT_DATA, 1 }, + .setscl = { 0x01, PORT_DATA, 1 }, + .getsda = { 0x20, PORT_STAT, 0 }, + .getscl = { 0x40, PORT_STAT, 0 }, + .init = { 0xfc, PORT_DATA, 0 }, + }, + /* type 7: One For All JP1 parallel port adapter */ + { + .setsda = { 0x01, PORT_DATA, 0 }, + .setscl = { 0x02, PORT_DATA, 0 }, + .getsda = { 0x80, PORT_STAT, 1 }, + .init = { 0x04, PORT_DATA, 1 }, + }, + /* type 8: VCT-jig */ + { + .setsda = { 0x04, PORT_DATA, 1 }, + .setscl = { 0x01, PORT_DATA, 1 }, + .getsda = { 0x40, PORT_STAT, 0 }, + .getscl = { 0x80, PORT_STAT, 1 }, + }, +}; + +/* ----- Device list ------------------------------------------------------ */ + +struct i2c_par { + struct pardevice *pdev; + struct i2c_adapter adapter; + struct i2c_algo_bit_data algo_data; + struct i2c_smbus_alert_setup alert_data; + struct i2c_client *ara; + struct list_head node; +}; + +static LIST_HEAD(adapter_list); +static DEFINE_MUTEX(adapter_list_lock); + +#define MAX_DEVICE 4 +static int parport[MAX_DEVICE] = {0, -1, -1, -1}; +module_param_array(parport, int, NULL, 0); +MODULE_PARM_DESC(parport, + "List of parallel ports to bind to, by index.\n" + " At most " __stringify(MAX_DEVICE) " devices are supported.\n" + " Default is one device connected to parport0.\n" +); + +static int type = -1; +module_param(type, int, 0); +MODULE_PARM_DESC(type, + "Type of adapter:\n" + " 0 = Philips adapter\n" + " 1 = home brew teletext adapter\n" + " 2 = Velleman K8000 adapter\n" + " 3 = ELV adapter\n" + " 4 = ADM1032 evaluation board\n" + " 5 = ADM1025, ADM1030 and ADM1031 evaluation boards\n" + " 6 = Barco LPT->DVI (K5800236) adapter\n" + " 7 = One For All JP1 parallel port adapter\n" + " 8 = VCT-jig\n" +); + +/* ----- Low-level parallel port access ----------------------------------- */ + +static void port_write_data(struct parport *p, unsigned char d) +{ + parport_write_data(p, d); +} + +static void port_write_control(struct parport *p, unsigned char d) +{ + parport_write_control(p, d); +} + +static unsigned char port_read_data(struct parport *p) +{ + return parport_read_data(p); +} + +static unsigned char port_read_status(struct parport *p) +{ + return parport_read_status(p); +} + +static unsigned char port_read_control(struct parport *p) +{ + return parport_read_control(p); +} + +static void (* const port_write[])(struct parport *, unsigned char) = { + port_write_data, + NULL, + port_write_control, +}; + +static unsigned char (* const port_read[])(struct parport *) = { + port_read_data, + port_read_status, + port_read_control, +}; + +/* ----- Unified line operation functions --------------------------------- */ + +static inline void line_set(struct parport *data, int state, + const struct lineop *op) +{ + u8 oldval = port_read[op->port](data); + + /* Touch only the bit(s) needed */ + if ((op->inverted && !state) || (!op->inverted && state)) + port_write[op->port](data, oldval | op->val); + else + port_write[op->port](data, oldval & ~op->val); +} + +static inline int line_get(struct parport *data, + const struct lineop *op) +{ + u8 oldval = port_read[op->port](data); + + return ((op->inverted && (oldval & op->val) != op->val) + || (!op->inverted && (oldval & op->val) == op->val)); +} + +/* ----- I2C algorithm call-back functions and structures ----------------- */ + +static void parport_setscl(void *data, int state) +{ + line_set((struct parport *) data, state, &adapter_parm[type].setscl); +} + +static void parport_setsda(void *data, int state) +{ + line_set((struct parport *) data, state, &adapter_parm[type].setsda); +} + +static int parport_getscl(void *data) +{ + return line_get((struct parport *) data, &adapter_parm[type].getscl); +} + +static int parport_getsda(void *data) +{ + return line_get((struct parport *) data, &adapter_parm[type].getsda); +} + +/* Encapsulate the functions above in the correct structure. + Note that this is only a template, from which the real structures are + copied. The attaching code will set getscl to NULL for adapters that + cannot read SCL back, and will also make the data field point to + the parallel port structure. */ +static const struct i2c_algo_bit_data parport_algo_data = { + .setsda = parport_setsda, + .setscl = parport_setscl, + .getsda = parport_getsda, + .getscl = parport_getscl, + .udelay = 10, /* ~50 kbps */ + .timeout = HZ, +}; + +/* ----- I2c and parallel port call-back functions and structures --------- */ + +static void i2c_parport_irq(void *data) +{ + struct i2c_par *adapter = data; + struct i2c_client *ara = adapter->ara; + + if (ara) { + dev_dbg(&ara->dev, "SMBus alert received\n"); + i2c_handle_smbus_alert(ara); + } else + dev_dbg(&adapter->adapter.dev, + "SMBus alert received but no ARA client!\n"); +} + +static void i2c_parport_attach(struct parport *port) +{ + struct i2c_par *adapter; + int i; + struct pardev_cb i2c_parport_cb; + + if (type < 0) { + pr_warn("adapter type unspecified\n"); + return; + } + + if (type >= ARRAY_SIZE(adapter_parm)) { + pr_warn("invalid type (%d)\n", type); + return; + } + + for (i = 0; i < MAX_DEVICE; i++) { + if (parport[i] == -1) + continue; + if (port->number == parport[i]) + break; + } + if (i == MAX_DEVICE) { + pr_debug("Not using parport%d.\n", port->number); + return; + } + + adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL); + if (!adapter) + return; + memset(&i2c_parport_cb, 0, sizeof(i2c_parport_cb)); + i2c_parport_cb.flags = PARPORT_FLAG_EXCL; + i2c_parport_cb.irq_func = i2c_parport_irq; + i2c_parport_cb.private = adapter; + + pr_debug("attaching to %s\n", port->name); + parport_disable_irq(port); + adapter->pdev = parport_register_dev_model(port, "i2c-parport", + &i2c_parport_cb, i); + if (!adapter->pdev) { + pr_err("Unable to register with parport\n"); + goto err_free; + } + + /* Fill the rest of the structure */ + adapter->adapter.owner = THIS_MODULE; + adapter->adapter.class = I2C_CLASS_HWMON; + strscpy(adapter->adapter.name, "Parallel port adapter", + sizeof(adapter->adapter.name)); + adapter->algo_data = parport_algo_data; + /* Slow down if we can't sense SCL */ + if (!adapter_parm[type].getscl.val) { + adapter->algo_data.getscl = NULL; + adapter->algo_data.udelay = 50; /* ~10 kbps */ + } + adapter->algo_data.data = port; + adapter->adapter.algo_data = &adapter->algo_data; + adapter->adapter.dev.parent = port->physport->dev; + + if (parport_claim_or_block(adapter->pdev) < 0) { + dev_err(&adapter->pdev->dev, + "Could not claim parallel port\n"); + goto err_unregister; + } + + /* Reset hardware to a sane state (SCL and SDA high) */ + parport_setsda(port, 1); + parport_setscl(port, 1); + /* Other init if needed (power on...) */ + if (adapter_parm[type].init.val) { + line_set(port, 1, &adapter_parm[type].init); + /* Give powered devices some time to settle */ + msleep(100); + } + + if (i2c_bit_add_bus(&adapter->adapter) < 0) { + dev_err(&adapter->pdev->dev, "Unable to register with I2C\n"); + goto err_unregister; + } + + /* Setup SMBus alert if supported */ + if (adapter_parm[type].smbus_alert) { + struct i2c_client *ara; + + ara = i2c_new_smbus_alert_device(&adapter->adapter, + &adapter->alert_data); + if (!IS_ERR(ara)) { + adapter->ara = ara; + parport_enable_irq(port); + } else { + dev_warn(&adapter->pdev->dev, + "Failed to register ARA client\n"); + } + } + + /* Add the new adapter to the list */ + mutex_lock(&adapter_list_lock); + list_add_tail(&adapter->node, &adapter_list); + mutex_unlock(&adapter_list_lock); + return; + + err_unregister: + parport_release(adapter->pdev); + parport_unregister_device(adapter->pdev); + err_free: + kfree(adapter); +} + +static void i2c_parport_detach(struct parport *port) +{ + struct i2c_par *adapter, *_n; + + /* Walk the list */ + mutex_lock(&adapter_list_lock); + list_for_each_entry_safe(adapter, _n, &adapter_list, node) { + if (adapter->pdev->port == port) { + if (adapter->ara) { + parport_disable_irq(port); + i2c_unregister_device(adapter->ara); + } + i2c_del_adapter(&adapter->adapter); + + /* Un-init if needed (power off...) */ + if (adapter_parm[type].init.val) + line_set(port, 0, &adapter_parm[type].init); + + parport_release(adapter->pdev); + parport_unregister_device(adapter->pdev); + list_del(&adapter->node); + kfree(adapter); + } + } + mutex_unlock(&adapter_list_lock); +} + +static struct parport_driver i2c_parport_driver = { + .name = "i2c-parport", + .match_port = i2c_parport_attach, + .detach = i2c_parport_detach, + .devmodel = true, +}; +module_parport_driver(i2c_parport_driver); + +MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); +MODULE_DESCRIPTION("I2C bus over parallel port"); +MODULE_LICENSE("GPL"); |