* 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.
+ *
+ * idea:
+ * separate the butterfly driver into a hotpluggable SPI master controller
+ * use a board description file, which loads the:
+ * - the SPI master controller
+ * - the SPI protocoll driver
+ * call spi_new_device with
+ - spi_master = butterfly parport driver (or parameter configurable)
+ - spi_board_info = infos about Mauro-Lite
+
*/
#include <linux/kernel.h>
#include <linux/init.h>
*/
/* DATA output bits (pins 2..9 == D0..D7) */
+#define MODALIASLEN 10
+#define DRVNAME "spi_butterfly"
+#define DRIVER_VERSION "0.2"
+
#define butterfly_nreset (1 << 1) /* pin 3 */
#define spi_sck_bit (1 << 0) /* pin 2 */
/* CONTROL output bits */
#define spi_cs_bit PARPORT_CONTROL_SELECT /* pin 17 */
+/*
+ * Parallel
+ * Port Direction Signal
+ * ----------- --------- ------------
+ * D0 2 --> SCLK
+ * D1 3 --> nRESET
+ * D2 4 --> --
+ * D3 5 --> --
+ * D4 6 --> --
+ * D5 7 --> --
+ * D6 8 --> --
+ * D7 9 --> MOSI
+ * GND 25 - GND
+ * Busy 11 <-- MISO
+ * Paper 12 <-- --
+ * Select 13 <-- --
+ * Feed 14 --> --
+ * Error 15 <-- --
+ * Init 16 --> --
+ * Select 17 --> nCS
+ */
+//*****************************************************************************
+// Globals
+//*****************************************************************************
+/* module parameters */
+static char modalias[MODALIASLEN] = "maurol";
static inline struct butterfly *spidev_to_pp(struct spi_device *spi)
{
struct parport *port;
struct pardevice *pd;
- u8 lastbyte;
+ u8 lastbyte; /* hold copy of partport to be faster */
struct spi_message *msg;
struct spi_device *butterfly;
- struct spi_board_info info[2];
+ struct spi_board_info info;
};
/*----------------------------------------------------------------------*/
+
static inline void
setsck(struct spi_device *spi, int is_on)
{
else
byte &= ~bit;
parport_write_data(pp->port, byte);
- pp->lastbyte = byte;
+ pp->lastbyte = byte; /* use parport mirror to be faster */
}
static inline void
else
byte &= ~bit;
parport_write_data(pp->port, byte);
- pp->lastbyte = byte;
+ pp->lastbyte = byte; /* use parport mirror to be faster */
}
static inline int getmiso(struct spi_device *spi)
{
struct butterfly *pp = spidev_to_pp(spi);
+#if 0
/* set default clock polarity */
if (value != BITBANG_CS_INACTIVE)
setsck(spi, spi->mode & SPI_CPOL);
value = !value;
parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
+#else
+ u8 bit, byte = pp->lastbyte;
+
+ bit = butterfly_nreset;
+
+ if (value)
+ byte &= ~bit;
+ else
+ byte |= bit;
+ parport_write_data(pp->port, byte);
+ pp->lastbyte = byte; /* use parport mirror to be faster */
+#endif
}
}
pp = spi_master_get_devdata(master);
+ master->bus_num = -1; /* dynamic alloc of a bus number */
+ master->num_chipselect = 1;
+
/*
* SPI and bitbang hookup
- *
+ *
* use default setup(), cleanup(), and transfer() methods; and
* only bother implementing mode 0. Start it later.
*/
- master->bus_num = 42; // hard coded?!?
- master->num_chipselect = 2; // hard coded?!?
-
pp->bitbang.master = spi_master_get(master);
pp->bitbang.chipselect = butterfly_chipselect;
pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
-
+ pp->bitbang.flags = SPI_3WIRE; // ####################################
+
/*
* parport hookup
*/
pp->port = p;
- pd = parport_register_device(p, "spi_butterfly",
+ pd = parport_register_device(p, DRVNAME,
NULL, NULL, NULL,
- 0 /* FLAGS */, pp);
+ 0 /* FLAGS */, pp); //PARPORT_FLAG_EXCL, pp);
if (!pd) {
status = -ENOMEM;
goto clean0;
if (status < 0)
goto clean1;
+ pp->lastbyte = 0;
+ parport_write_data(pp->port, pp->lastbyte);
+
/*
* Butterfly reset, powerup, run firmware
*/
- pr_debug("%s: powerup/reset Butterfly\n", p->name);
+ pr_debug("%s: powerup/reset Butterfly\n", DRVNAME);
/* nCS for dataflash (this bit is inverted on output) */
parport_frob_control(pp->port, spi_cs_bit, 0);
parport_write_data(pp->port, pp->lastbyte);
msleep(5);
+#if 0
/* take it out of reset; assume long reset delay */
pp->lastbyte |= butterfly_nreset;
parport_write_data(pp->port, pp->lastbyte);
- msleep(100);
+ msleep(10);
+ /* take reset as trigger signal ############# */
+ pp->lastbyte &= ~butterfly_nreset;
+ parport_write_data(pp->port, pp->lastbyte);
+#endif
/*
* Start SPI ... for now, hide that we're two physical busses.
*/
status = spi_bitbang_start(&pp->bitbang);
- if (status < 0)
+ if (status < 0) {
+ pr_warning("%s: spi_bitbang_start failed with status %d\n",
+ DRVNAME, status);
goto clean2;
+ }
- /* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR
- * (firmware resets at45, acts as spi slave) or neither (we ignore
- * both, AVR uses AT45). Here we expect firmware for the first option.
+ /*
+ * 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.
*/
-
- pp->info[0].max_speed_hz = 15 * 1000 * 1000;
-
- strcpy(pp->info[0].modalias, "spi_tty"); // name length check ! < KOBJ_NAME_LEN
- pp->info[0].platform_data = NULL; // here we should add data structures for subsystem driver ???
- pp->info[0].chip_select = 1; // 0: .. 1:
- pp->info[0].controller_data = pp; /* save my structure for later use */
- pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info[0]);
+ if (modalias[0]) {
+ pr_info("%s: Will load protocol driver: '%s'!\n", DRVNAME, modalias);
+ } else goto clean2;
+
+ /* need to make this parameter loadable */
+ strcpy(pp->info.modalias, modalias);
+ pp->info.max_speed_hz = 15 * 1000 * 1000;
+ pp->info.chip_select = 0; // 0: .. 1:
+ pp->info.mode = SPI_3WIRE | SPI_MODE_0; // ################
+
+ /* Enable access to our primary data structure via
+ * the board info's (void *)controller_data.
+ */
+ pp->info.platform_data = NULL; // here we should add data structures for subsystem driver ???
+ pp->info.controller_data = pp; /* save my structure for later use */
+ pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info);
if (pp->butterfly)
- pr_debug("%s: dataflash at %s\n", p->name,
+ pr_info("%s: SPI tty at %s\n", DRVNAME,
pp->butterfly->dev.bus_id);
-
- // dev_info(_what?_, ...)
- pr_info("%s: AVR Butterfly\n", p->name);
-
+ else {
+ pr_warning("%s: spi_new_device failed\n", DRVNAME);
+ status = -ENODEV;
+ goto out_bitbang_stop;
+ }
+ // pp->butterfly->bits_per_word=16; // ###############
/* get spi_bitbang_transfer either via global Symbol, or better
* ask it from the driver structure
butterfly = pp;
return;
+out_bitbang_stop:
+ spi_bitbang_stop(&pp->bitbang);
clean2:
/* turn off VCC */
parport_write_data(pp->port, 0);
clean0:
(void) spi_master_put(pp->bitbang.master);
done:
- pr_debug("%s: butterfly probe, fail %d\n", p->name, status);
+ pr_debug("%s: butterfly probe, fail %d\n", DRVNAME, status);
}
static void butterfly_detach(struct parport *p)
spi_message_free(pp->msg);
pr_info("Dealloc SPI message buffer\n");
}
- butterfly = NULL;
/* stop() unregisters child devices too */
status = spi_bitbang_stop(&pp->bitbang);
parport_unregister_device(pp->pd);
(void) spi_master_put(pp->bitbang.master);
+
+ butterfly = NULL;
}
static struct parport_driver butterfly_driver = {
- .name = "spi_butterfly",
+ .name = DRVNAME,
.attach = butterfly_attach,
.detach = butterfly_detach,
};
MODULE_DESCRIPTION("Parport Adapter driver for SPI tty Butterfly");
MODULE_LICENSE("GPL");
+
+module_param_string(spi_pdrv, modalias, sizeof(modalias), S_IRUGO);
+MODULE_PARM_DESC(spi_pdrv, "spi protocol driver name");
+
+MODULE_INFO(Version, DRIVER_VERSION);
projects / pub / spi-gpio-pp.git / commitdiff