Hi Michael, On Tue, 04 May 2010 14:48:21 +0200, Michael Lawnick wrote: > Add multiplexed bus core support. I2C driver for PCA954x > I2C multiplexer series. > > Signed-off-by: Michael Lawnick <[email protected]>
Review: > > --- > Based on kernel 2.6.33 + > [PATCH] i2c-core: Use per-adapter userspace device lists > by Jean Delware <[email protected]> > <http://article.gmane.org/gmane.linux.drivers.i2c/5994/> > > drivers/i2c/Kconfig | 2 + > drivers/i2c/Makefile | 2 +- > drivers/i2c/muxes/Kconfig | 17 +++ > drivers/i2c/muxes/Makefile | 8 + > drivers/i2c/muxes/pca954x.c | 302 > +++++++++++++++++++++++++++++++++++++++++++ > include/linux/i2c/pca954x.h | 47 +++++++ > 6 files changed, 377 insertions(+), 1 deletions(-) > create mode 100755 drivers/i2c/muxes/Kconfig > create mode 100755 drivers/i2c/muxes/Makefile > create mode 100755 drivers/i2c/muxes/pca954x.c > create mode 100755 include/linux/i2c/pca954x.h I don't really care, as I use quilt for my patches, but the above modes are wrong: should be 100644. > > diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig > index 2cd6d78..21b0ac0 100755 > --- a/drivers/i2c/Kconfig > +++ b/drivers/i2c/Kconfig > @@ -44,6 +44,8 @@ config I2C_MUX > handle multiplexed I2C bus topologies, by presenting each > multiplexed segment as a I2C adapter. > > +source drivers/i2c/muxes/Kconfig > + > config I2C_CHARDEV > tristate "I2C device interface" > help > diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile > index a488e8b..1769a16 100755 > --- a/drivers/i2c/Makefile > +++ b/drivers/i2c/Makefile > @@ -6,7 +6,7 @@ obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o > obj-$(CONFIG_I2C) += i2c-core.o > obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o > obj-$(CONFIG_I2C_MUX) += i2c-mux.o > -obj-y += busses/ chips/ algos/ > +obj-y += busses/ chips/ muxes/ algos/ > > ifeq ($(CONFIG_I2C_DEBUG_CORE),y) > EXTRA_CFLAGS += -DDEBUG > diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig > new file mode 100755 > index 0000000..ec22db0 > --- /dev/null > +++ b/drivers/i2c/muxes/Kconfig > @@ -0,0 +1,17 @@ > +# > +# Multiplexer I2C chip drivers configuration > +# > + > +menu "Multiplexer I2C Chip support" > + depends on I2C_MUX && EXPERIMENTAL The dependency on EXPERIMENTAL is odd for a menu. I'd rather move it down to individual drivers, so that we can them remove them later on a case-by-case basis. > + > +config I2C_MUX_PCA954x > + tristate "Philips PCA954x I2C Mux/switches" > + help > + If you say yes here you get support for the Philips PCA954x > + I2C mux/switch devices. > + > + This driver can also be built as a module. If so, the module > + will be called pca954x. > + > +endmenu > diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile > new file mode 100755 > index 0000000..575c1ca > --- /dev/null > +++ b/drivers/i2c/muxes/Makefile > @@ -0,0 +1,8 @@ > +# > +# Makefile for multiplexer I2C chip drivers. > + > +obj-$(CONFIG_I2C_MUX_PCA954x) += pca954x.o > + > +ifeq ($(I2C_DEBUG_BUS),y) I think you mean CONFIG_I2C_DEBUG_BUS here. > +EXTRA_CFLAGS += -DDEBUG > +endif > diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c > new file mode 100755 > index 0000000..12b5eb7 > --- /dev/null > +++ b/drivers/i2c/muxes/pca954x.c > @@ -0,0 +1,302 @@ > +/* > + * I2C multiplexer > + * > + * Copyright (c) 2008-2009 Rodolfo Giometti <[email protected]> > + * Copyright (c) 2008-2009 Eurotech S.p.A. <[email protected]> > + * > + * 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 <[email protected]> > + * 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 <[email protected]> > + * and > + * pca9540.c from Jean Delvare <[email protected]>. > + * > + * 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; This indentation doesn't make much sense. > +}; > + > +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; Useless initialization. > + > + if (adap->algo->master_xfer) { > + struct i2c_msg msg; > + char buf[1]; > + > + msg.addr = client->addr; > + msg.flags = I2C_SMBUS_WRITE; That's not correct. You want to use 0 here (as writes are the default, in the absence of I2C_M_RD). > + 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 != chan) { > + ret = pca954x_reg_write(adap, client, regval); > + data->last_chan = chan; > + } > + > + 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 __devinit 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); > + > + /* Read the mux register at addr to verify > + * that the mux is in fact present. > + */ > + if (i2c_smbus_read_byte(client) < 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); Functions are already addresses, the leading & isn't needed. > + > + if (data->virt_adaps[num] == NULL) { > + ret = -ENODEV; > + printk(KERN_ERR Please use dev_err(). > + "%s %s: failed to register multiplexed adapter" > + " %d at bus %d\n", __FILE__, __func__, num, I think you mean "as bus", not "at bus". > + 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 __devexit 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 = __devexit_p(pca954x_remove), > + .id_table = pca954x_id, > +}; > + > +static int __init pca954x_init(void) > +{ > + return i2c_add_driver(&pca954x_driver); > +} > + > +static void __exit pca954x_exit(void) > +{ > + i2c_del_driver(&pca954x_driver); > +} > + > +module_init(pca954x_init); > +module_exit(pca954x_exit); > + > +MODULE_AUTHOR("Rodolfo Giometti <[email protected]>"); > +MODULE_DESCRIPTION("PCA954x I2C mux/switch driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/linux/i2c/pca954x.h b/include/linux/i2c/pca954x.h > new file mode 100755 > index 0000000..8032269 > --- /dev/null > +++ b/include/linux/i2c/pca954x.h > @@ -0,0 +1,47 @@ > +/* > + * > + * pca954x.h - I2C multiplexer/switch support > + * > + * Copyright (c) 2008-2009 Rodolfo Giometti <[email protected]> > + * Copyright (c) 2008-2009 Eurotech S.p.A. <[email protected]> > + * Michael Lawnick <[email protected]> > + * > + * 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. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. > + */ > + > + > +#ifndef _I2C_PCA954X_H Should be prefixed with _LINUX to avoid any confusion. > +#define _I2C_PCA954X_H > + > +/* Platform data for the PCA954x I2C multiplexers */ > + > +/* Per channel initialisation data: > + * @adap_id: bus number for the adapter. 0 = don't care > + * @deselect_on_exit: set this entry to 1, if your H/W needs deselection > + * of this channel after transaction. > + * > + */ > +struct pca954x_platform_mode { > + int adap_id; > + unsigned int deselect_on_exit:1; > +}; > + > +/* Per mux/switch data, used with i2c_register_board_info */ > +struct pca954x_platform_data { > + struct pca954x_platform_mode *modes; > + int num_modes; Please use tabs for indentation. > +}; > + > +#endif /*_I2C_PCA954X_H*/ Missing spaces. I've fixed all these small issues myself; no need to resend. Thanks (to you and Rodolfo as well) for your contribution! -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
