diff options
Diffstat (limited to 'drivers/spi/spi_lm70llp.c')
| -rw-r--r-- | drivers/spi/spi_lm70llp.c | 351 |
1 files changed, 0 insertions, 351 deletions
diff --git a/drivers/spi/spi_lm70llp.c b/drivers/spi/spi_lm70llp.c deleted file mode 100644 index 7746a41ab6d6..000000000000 --- a/drivers/spi/spi_lm70llp.c +++ /dev/null @@ -1,351 +0,0 @@ -/* - * spi_lm70llp.c - driver for LM70EVAL-LLP board for the LM70 sensor - * - * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.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. - * - * 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. - */ - -#include <linux/init.h> -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/delay.h> -#include <linux/device.h> -#include <linux/parport.h> -#include <linux/sysfs.h> -#include <linux/workqueue.h> - - -#include <linux/spi/spi.h> -#include <linux/spi/spi_bitbang.h> - - -/* - * The LM70 communicates with a host processor using a 3-wire variant of - * the SPI/Microwire bus interface. This driver specifically supports an - * NS LM70 LLP Evaluation Board, interfacing to a PC using its parallel - * port to bitbang an SPI-parport bridge. Accordingly, this is an SPI - * master controller driver. The hwmon/lm70 driver is a "SPI protocol - * driver", layered on top of this one and usable without the lm70llp. - * - * Datasheet and Schematic: - * The LM70 is a temperature sensor chip from National Semiconductor; its - * datasheet is available at http://www.national.com/pf/LM/LM70.html - * The schematic for this particular board (the LM70EVAL-LLP) is - * available (on page 4) here: - * http://www.national.com/appinfo/tempsensors/files/LM70LLPEVALmanual.pdf - * - * Also see Documentation/spi/spi-lm70llp. The SPI<->parport code here is - * (heavily) based on spi-butterfly by David Brownell. - * - * The LM70 LLP connects to the PC parallel port in the following manner: - * - * Parallel LM70 LLP - * Port Direction JP2 Header - * ----------- --------- ------------ - * D0 2 - - - * D1 3 --> V+ 5 - * D2 4 --> V+ 5 - * D3 5 --> V+ 5 - * D4 6 --> V+ 5 - * D5 7 --> nCS 8 - * D6 8 --> SCLK 3 - * D7 9 --> SI/O 5 - * GND 25 - GND 7 - * Select 13 <-- SI/O 1 - * - * Note that parport pin 13 actually gets inverted by the transistor - * arrangement which lets either the parport or the LM70 drive the - * SI/SO signal (see the schematic for details). - */ - -#define DRVNAME "spi-lm70llp" - -#define lm70_INIT 0xBE -#define SIO 0x10 -#define nCS 0x20 -#define SCLK 0x40 - -/*-------------------------------------------------------------------------*/ - -struct spi_lm70llp { - struct spi_bitbang bitbang; - struct parport *port; - struct pardevice *pd; - struct spi_device *spidev_lm70; - struct spi_board_info info; - //struct device *dev; -}; - -/* REVISIT : ugly global ; provides "exclusive open" facility */ -static struct spi_lm70llp *lm70llp; - - -/*-------------------------------------------------------------------*/ - -static inline struct spi_lm70llp *spidev_to_pp(struct spi_device *spi) -{ - return spi->controller_data; -} - -/*---------------------- LM70 LLP eval board-specific inlines follow */ - -/* NOTE: we don't actually need to reread the output values, since they'll - * still be what we wrote before. Plus, going through parport builds in - * a ~1ms/operation delay; these SPI transfers could easily be faster. - */ - -static inline void deassertCS(struct spi_lm70llp *pp) -{ - u8 data = parport_read_data(pp->port); - - data &= ~0x80; /* pull D7/SI-out low while de-asserted */ - parport_write_data(pp->port, data | nCS); -} - -static inline void assertCS(struct spi_lm70llp *pp) -{ - u8 data = parport_read_data(pp->port); - - data |= 0x80; /* pull D7/SI-out high so lm70 drives SO-in */ - parport_write_data(pp->port, data & ~nCS); -} - -static inline void clkHigh(struct spi_lm70llp *pp) -{ - u8 data = parport_read_data(pp->port); - parport_write_data(pp->port, data | SCLK); -} - -static inline void clkLow(struct spi_lm70llp *pp) -{ - u8 data = parport_read_data(pp->port); - parport_write_data(pp->port, data & ~SCLK); -} - -/*------------------------- SPI-LM70-specific inlines ----------------------*/ - -static inline void spidelay(unsigned d) -{ - udelay(d); -} - -static inline void setsck(struct spi_device *s, int is_on) -{ - struct spi_lm70llp *pp = spidev_to_pp(s); - - if (is_on) - clkHigh(pp); - else - clkLow(pp); -} - -static inline void setmosi(struct spi_device *s, int is_on) -{ - /* FIXME update D7 ... this way we can put the chip - * into shutdown mode and read the manufacturer ID, - * but we can't put it back into operational mode. - */ -} - -/* - * getmiso: - * Why do we return 0 when the SIO line is high and vice-versa? - * The fact is, the lm70 eval board from NS (which this driver drives), - * is wired in just such a way : when the lm70's SIO goes high, a transistor - * switches it to low reflecting this on the parport (pin 13), and vice-versa. - */ -static inline int getmiso(struct spi_device *s) -{ - struct spi_lm70llp *pp = spidev_to_pp(s); - return ((SIO == (parport_read_status(pp->port) & SIO)) ? 0 : 1 ); -} -/*--------------------------------------------------------------------*/ - -#include "spi_bitbang_txrx.h" - -static void lm70_chipselect(struct spi_device *spi, int value) -{ - struct spi_lm70llp *pp = spidev_to_pp(spi); - - if (value) - assertCS(pp); - else - deassertCS(pp); -} - -/* - * Our actual bitbanger routine. - */ -static u32 lm70_txrx(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits) -{ - return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); -} - -static void spi_lm70llp_attach(struct parport *p) -{ - struct pardevice *pd; - struct spi_lm70llp *pp; - struct spi_master *master; - int status; - - if (lm70llp) { - printk(KERN_WARNING - "%s: spi_lm70llp instance already loaded. Aborting.\n", - DRVNAME); - return; - } - - /* TODO: this just _assumes_ a lm70 is there ... no probe; - * the lm70 driver could verify it, reading the manf ID. - */ - - master = spi_alloc_master(p->physport->dev, sizeof *pp); - if (!master) { - status = -ENOMEM; - goto out_fail; - } - pp = spi_master_get_devdata(master); - - master->bus_num = -1; /* dynamic alloc of a bus number */ - master->num_chipselect = 1; - - /* - * SPI and bitbang hookup. - */ - pp->bitbang.master = spi_master_get(master); - pp->bitbang.chipselect = lm70_chipselect; - pp->bitbang.txrx_word[SPI_MODE_0] = lm70_txrx; - pp->bitbang.flags = SPI_3WIRE; - - /* - * Parport hookup - */ - pp->port = p; - pd = parport_register_device(p, DRVNAME, - NULL, NULL, NULL, - PARPORT_FLAG_EXCL, pp); - if (!pd) { - status = -ENOMEM; - goto out_free_master; - } - pp->pd = pd; - - status = parport_claim(pd); - if (status < 0) - goto out_parport_unreg; - - /* - * Start SPI ... - */ - status = spi_bitbang_start(&pp->bitbang); - if (status < 0) { - printk(KERN_WARNING - "%s: spi_bitbang_start failed with status %d\n", - DRVNAME, status); - goto out_off_and_release; - } - - /* - * The modalias name MUST match the device_driver name - * for the bus glue code to match and subsequently bind them. - * We are binding to the generic drivers/hwmon/lm70.c device - * driver. - */ - strcpy(pp->info.modalias, "lm70"); - pp->info.max_speed_hz = 6 * 1000 * 1000; - pp->info.chip_select = 0; - pp->info.mode = SPI_3WIRE | SPI_MODE_0; - - /* power up the chip, and let the LM70 control SI/SO */ - parport_write_data(pp->port, lm70_INIT); - - /* Enable access to our primary data structure via - * the board info's (void *)controller_data. - */ - pp->info.controller_data = pp; - pp->spidev_lm70 = spi_new_device(pp->bitbang.master, &pp->info); - if (pp->spidev_lm70) - dev_dbg(&pp->spidev_lm70->dev, "spidev_lm70 at %s\n", - dev_name(&pp->spidev_lm70->dev)); - else { - printk(KERN_WARNING "%s: spi_new_device failed\n", DRVNAME); - status = -ENODEV; - goto out_bitbang_stop; - } - pp->spidev_lm70->bits_per_word = 8; - - lm70llp = pp; - return; - -out_bitbang_stop: - spi_bitbang_stop(&pp->bitbang); -out_off_and_release: - /* power down */ - parport_write_data(pp->port, 0); - mdelay(10); - parport_release(pp->pd); -out_parport_unreg: - parport_unregister_device(pd); -out_free_master: - (void) spi_master_put(master); -out_fail: - pr_info("%s: spi_lm70llp probe fail, status %d\n", DRVNAME, status); -} - -static void spi_lm70llp_detach(struct parport *p) -{ - struct spi_lm70llp *pp; - - if (!lm70llp || lm70llp->port != p) - return; - - pp = lm70llp; - spi_bitbang_stop(&pp->bitbang); - - /* power down */ - parport_write_data(pp->port, 0); - - parport_release(pp->pd); - parport_unregister_device(pp->pd); - - (void) spi_master_put(pp->bitbang.master); - - lm70llp = NULL; -} - - -static struct parport_driver spi_lm70llp_drv = { - .name = DRVNAME, - .attach = spi_lm70llp_attach, - .detach = spi_lm70llp_detach, -}; - -static int __init init_spi_lm70llp(void) -{ - return parport_register_driver(&spi_lm70llp_drv); -} -module_init(init_spi_lm70llp); - -static void __exit cleanup_spi_lm70llp(void) -{ - parport_unregister_driver(&spi_lm70llp_drv); -} -module_exit(cleanup_spi_lm70llp); - -MODULE_AUTHOR("Kaiwan N Billimoria <kaiwan@designergraphix.com>"); -MODULE_DESCRIPTION( - "Parport adapter for the National Semiconductor LM70 LLP eval board"); -MODULE_LICENSE("GPL"); |