2  * Driver for LM70EVAL-LLP board for the LM70 sensor
32  * The LM70 communicates with a host processor using a 3-wire variant of
34  * NS LM70 LLP Evaluation Board, interfacing to a PC using its parallel
35  * port to bitbang an SPI-parport bridge.  Accordingly, this is an SPI
42  * The schematic for this particular board (the LM70EVAL-LLP) is
46  * Also see Documentation/spi/spi-lm70llp.  The SPI<->parport code here is
47  * (heavily) based on spi-butterfly by David Brownell.
49  * The LM70 LLP connects to the PC parallel port in the following manner:
51  *   Parallel                 LM70 LLP
53  *  -----------  ---------  ------------
54  *      D0    2      -         -
55  *      D1    3     -->      V+   5
56  *      D2    4     -->      V+   5
57  *      D3    5     -->      V+   5
58  *      D4    6     -->      V+   5
59  *      D5    7     -->      nCS  8
60  *      D6    8     -->      SCLK 3
61  *      D7    9     -->      SI/O 5
62  *     GND   25      -       GND  7
63  *    Select 13     <--      SI/O 1
70 #define DRVNAME		"spi-lm70llp"
77 /*-------------------------------------------------------------------------*/
91 /*-------------------------------------------------------------------*/
95 	return spi->controller_data;  in spidev_to_pp()
98 /*---------------------- LM70 LLP eval board-specific inlines follow */
107 	u8 data = parport_read_data(pp->port);  in deassertCS()
109 	data &= ~0x80;		/* pull D7/SI-out low while de-asserted */  in deassertCS()
110 	parport_write_data(pp->port, data | nCS);  in deassertCS()
115 	u8 data = parport_read_data(pp->port);  in assertCS()
117 	data |= 0x80;		/* pull D7/SI-out high so lm70 drives SO-in */  in assertCS()
118 	parport_write_data(pp->port, data & ~nCS);  in assertCS()
123 	u8 data = parport_read_data(pp->port);  in clkHigh()
125 	parport_write_data(pp->port, data | SCLK);  in clkHigh()
130 	u8 data = parport_read_data(pp->port);  in clkLow()
132 	parport_write_data(pp->port, data & ~SCLK);  in clkLow()
135 /*------------------------- SPI-LM70-specific inlines ----------------------*/
162  * Why do we return 0 when the SIO line is high and vice-versa?
165  * switches it to low reflecting this on the parport (pin 13), and vice-versa.
171 	return ((SIO == (parport_read_status(pp->port) & SIO)) ? 0 : 1);  in getmiso()
174 /*--------------------------------------------------------------------*/
176 #include "spi-bitbang-txrx.h"
214 	master = spi_alloc_master(p->physport->dev, sizeof *pp);  in spi_lm70llp_attach()
216 		status = -ENOMEM;  in spi_lm70llp_attach()
224 	pp->bitbang.master = master;  in spi_lm70llp_attach()
225 	pp->bitbang.chipselect = lm70_chipselect;  in spi_lm70llp_attach()
226 	pp->bitbang.txrx_word[SPI_MODE_0] = lm70_txrx;  in spi_lm70llp_attach()
227 	pp->bitbang.flags = SPI_3WIRE;  in spi_lm70llp_attach()
232 	pp->port = p;  in spi_lm70llp_attach()
239 		status = -ENOMEM;  in spi_lm70llp_attach()
242 	pp->pd = pd;  in spi_lm70llp_attach()
251 	status = spi_bitbang_start(&pp->bitbang);  in spi_lm70llp_attach()
253 		dev_warn(&pd->dev, "spi_bitbang_start failed with status %d\n",  in spi_lm70llp_attach()
264 	strcpy(pp->info.modalias, "lm70");  in spi_lm70llp_attach()
265 	pp->info.max_speed_hz = 6 * 1000 * 1000;  in spi_lm70llp_attach()
266 	pp->info.chip_select = 0;  in spi_lm70llp_attach()
267 	pp->info.mode = SPI_3WIRE | SPI_MODE_0;  in spi_lm70llp_attach()
270 	parport_write_data(pp->port, lm70_INIT);  in spi_lm70llp_attach()
275 	pp->info.controller_data = pp;  in spi_lm70llp_attach()
276 	pp->spidev_lm70 = spi_new_device(pp->bitbang.master, &pp->info);  in spi_lm70llp_attach()
277 	if (pp->spidev_lm70)  in spi_lm70llp_attach()
278 		dev_dbg(&pp->spidev_lm70->dev, "spidev_lm70 at %s\n",  in spi_lm70llp_attach()
279 			dev_name(&pp->spidev_lm70->dev));  in spi_lm70llp_attach()
281 		dev_warn(&pd->dev, "spi_new_device failed\n");  in spi_lm70llp_attach()
282 		status = -ENODEV;  in spi_lm70llp_attach()
285 	pp->spidev_lm70->bits_per_word = 8;  in spi_lm70llp_attach()
291 	spi_bitbang_stop(&pp->bitbang);  in spi_lm70llp_attach()
294 	parport_write_data(pp->port, 0);  in spi_lm70llp_attach()
296 	parport_release(pp->pd);  in spi_lm70llp_attach()
309 	if (!lm70llp || lm70llp->port != p)  in spi_lm70llp_detach()
313 	spi_bitbang_stop(&pp->bitbang);  in spi_lm70llp_detach()
316 	parport_write_data(pp->port, 0);  in spi_lm70llp_detach()
318 	parport_release(pp->pd);  in spi_lm70llp_detach()
319 	parport_unregister_device(pp->pd);  in spi_lm70llp_detach()
321 	spi_master_put(pp->bitbang.master);  in spi_lm70llp_detach()
347 	"Parport adapter for the National Semiconductor LM70 LLP eval board");