diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/i2c/muxes/pca954x.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/i2c/muxes/pca954x.c | 291 |
1 files changed, 0 insertions, 291 deletions
diff --git a/ANDROID_3.4.5/drivers/i2c/muxes/pca954x.c b/ANDROID_3.4.5/drivers/i2c/muxes/pca954x.c deleted file mode 100644 index 0e37ef27..00000000 --- a/ANDROID_3.4.5/drivers/i2c/muxes/pca954x.c +++ /dev/null @@ -1,291 +0,0 @@ -/* - * I2C multiplexer - * - * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it> - * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it> - * - * This module supports the PCA954x series of I2C multiplexer/switch chips - * made by Philips Semiconductors. - * This includes the: - * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547 - * and PCA9548. - * - * These chips are all controlled via the I2C bus itself, and all have a - * single 8-bit register. The upstream "parent" bus fans out to two, - * four, or eight downstream busses or channels; which of these - * are selected is determined by the chip type and register contents. A - * mux can select only one sub-bus at a time; a switch can select any - * combination simultaneously. - * - * Based on: - * pca954x.c from Kumar Gala <galak@kernel.crashing.org> - * Copyright (C) 2006 - * - * Based on: - * pca954x.c from Ken Harrenstien - * Copyright (C) 2004 Google, Inc. (Ken Harrenstien) - * - * Based on: - * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com> - * and - * pca9540.c from Jean Delvare <khali@linux-fr.org>. - * - * This file is licensed under the terms of the GNU General Public - * License version 2. This program is licensed "as is" without any - * warranty of any kind, whether express or implied. - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/slab.h> -#include <linux/device.h> -#include <linux/i2c.h> -#include <linux/i2c-mux.h> - -#include <linux/i2c/pca954x.h> - -#define PCA954X_MAX_NCHANS 8 - -enum pca_type { - pca_9540, - pca_9542, - pca_9543, - pca_9544, - pca_9545, - pca_9546, - pca_9547, - pca_9548, -}; - -struct pca954x { - enum pca_type type; - struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS]; - - u8 last_chan; /* last register value */ -}; - -struct chip_desc { - u8 nchans; - u8 enable; /* used for muxes only */ - enum muxtype { - pca954x_ismux = 0, - pca954x_isswi - } muxtype; -}; - -/* Provide specs for the PCA954x types we know about */ -static const struct chip_desc chips[] = { - [pca_9540] = { - .nchans = 2, - .enable = 0x4, - .muxtype = pca954x_ismux, - }, - [pca_9543] = { - .nchans = 2, - .muxtype = pca954x_isswi, - }, - [pca_9544] = { - .nchans = 4, - .enable = 0x4, - .muxtype = pca954x_ismux, - }, - [pca_9545] = { - .nchans = 4, - .muxtype = pca954x_isswi, - }, - [pca_9547] = { - .nchans = 8, - .enable = 0x8, - .muxtype = pca954x_ismux, - }, - [pca_9548] = { - .nchans = 8, - .muxtype = pca954x_isswi, - }, -}; - -static const struct i2c_device_id pca954x_id[] = { - { "pca9540", pca_9540 }, - { "pca9542", pca_9540 }, - { "pca9543", pca_9543 }, - { "pca9544", pca_9544 }, - { "pca9545", pca_9545 }, - { "pca9546", pca_9545 }, - { "pca9547", pca_9547 }, - { "pca9548", pca_9548 }, - { } -}; -MODULE_DEVICE_TABLE(i2c, pca954x_id); - -/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer() - for this as they will try to lock adapter a second time */ -static int pca954x_reg_write(struct i2c_adapter *adap, - struct i2c_client *client, u8 val) -{ - int ret = -ENODEV; - - if (adap->algo->master_xfer) { - struct i2c_msg msg; - char buf[1]; - - msg.addr = client->addr; - msg.flags = 0; - msg.len = 1; - buf[0] = val; - msg.buf = buf; - ret = adap->algo->master_xfer(adap, &msg, 1); - } else { - union i2c_smbus_data data; - ret = adap->algo->smbus_xfer(adap, client->addr, - client->flags, - I2C_SMBUS_WRITE, - val, I2C_SMBUS_BYTE, &data); - } - - return ret; -} - -static int pca954x_select_chan(struct i2c_adapter *adap, - void *client, u32 chan) -{ - struct pca954x *data = i2c_get_clientdata(client); - const struct chip_desc *chip = &chips[data->type]; - u8 regval; - int ret = 0; - - /* we make switches look like muxes, not sure how to be smarter */ - if (chip->muxtype == pca954x_ismux) - regval = chan | chip->enable; - else - regval = 1 << chan; - - /* Only select the channel if its different from the last channel */ - if (data->last_chan != regval) { - ret = pca954x_reg_write(adap, client, regval); - data->last_chan = regval; - } - - return ret; -} - -static int pca954x_deselect_mux(struct i2c_adapter *adap, - void *client, u32 chan) -{ - struct pca954x *data = i2c_get_clientdata(client); - - /* Deselect active channel */ - data->last_chan = 0; - return pca954x_reg_write(adap, client, data->last_chan); -} - -/* - * I2C init/probing/exit functions - */ -static int pca954x_probe(struct i2c_client *client, - const struct i2c_device_id *id) -{ - struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent); - struct pca954x_platform_data *pdata = client->dev.platform_data; - int num, force; - struct pca954x *data; - int ret = -ENODEV; - - if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE)) - goto err; - - data = kzalloc(sizeof(struct pca954x), GFP_KERNEL); - if (!data) { - ret = -ENOMEM; - goto err; - } - - i2c_set_clientdata(client, data); - - /* Write the mux register at addr to verify - * that the mux is in fact present. This also - * initializes the mux to disconnected state. - */ - if (i2c_smbus_write_byte(client, 0) < 0) { - dev_warn(&client->dev, "probe failed\n"); - goto exit_free; - } - - data->type = id->driver_data; - data->last_chan = 0; /* force the first selection */ - - /* Now create an adapter for each channel */ - for (num = 0; num < chips[data->type].nchans; num++) { - force = 0; /* dynamic adap number */ - if (pdata) { - if (num < pdata->num_modes) - /* force static number */ - force = pdata->modes[num].adap_id; - else - /* discard unconfigured channels */ - break; - } - - data->virt_adaps[num] = - i2c_add_mux_adapter(adap, client, - force, num, pca954x_select_chan, - (pdata && pdata->modes[num].deselect_on_exit) - ? pca954x_deselect_mux : NULL); - - if (data->virt_adaps[num] == NULL) { - ret = -ENODEV; - dev_err(&client->dev, - "failed to register multiplexed adapter" - " %d as bus %d\n", num, force); - goto virt_reg_failed; - } - } - - dev_info(&client->dev, - "registered %d multiplexed busses for I2C %s %s\n", - num, chips[data->type].muxtype == pca954x_ismux - ? "mux" : "switch", client->name); - - return 0; - -virt_reg_failed: - for (num--; num >= 0; num--) - i2c_del_mux_adapter(data->virt_adaps[num]); -exit_free: - kfree(data); -err: - return ret; -} - -static int pca954x_remove(struct i2c_client *client) -{ - struct pca954x *data = i2c_get_clientdata(client); - const struct chip_desc *chip = &chips[data->type]; - int i, err; - - for (i = 0; i < chip->nchans; ++i) - if (data->virt_adaps[i]) { - err = i2c_del_mux_adapter(data->virt_adaps[i]); - if (err) - return err; - data->virt_adaps[i] = NULL; - } - - kfree(data); - return 0; -} - -static struct i2c_driver pca954x_driver = { - .driver = { - .name = "pca954x", - .owner = THIS_MODULE, - }, - .probe = pca954x_probe, - .remove = pca954x_remove, - .id_table = pca954x_id, -}; - -module_i2c_driver(pca954x_driver); - -MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); -MODULE_DESCRIPTION("PCA954x I2C mux/switch driver"); -MODULE_LICENSE("GPL v2"); |