/*      $NetBSD: bmx280thpi2c.c,v 1.1 2022/12/03 01:04:43 brad Exp $    */

/*
* Copyright (c) 2022 Brad Spencer <[email protected]>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bmx280thpi2c.c,v 1.1 2022/12/03 01:04:43 brad Exp $");

/*
* I2C driver for the Bosch BMP280 / BME280 sensor.
* Uses the common bmx280thp driver to do the real work.
*/

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/module.h>
#include <sys/conf.h>
#include <sys/sysctl.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/pool.h>
#include <sys/kmem.h>

#include <dev/sysmon/sysmonvar.h>
#include <dev/i2c/i2cvar.h>
#include <dev/spi/spivar.h>
#include <dev/ic/bmx280reg.h>
#include <dev/ic/bmx280var.h>

extern void     bmx280_attach(struct bmx280_sc *);

static int      bmx280thpi2c_poke(i2c_tag_t, i2c_addr_t, bool);
static int      bmx280thpi2c_match(device_t, cfdata_t, void *);
static void     bmx280thpi2c_attach(device_t, device_t, void *);
static int      bmx280thpi2c_detach(device_t, int);

#define BMX280_DEBUG
#ifdef BMX280_DEBUG
#define DPRINTF(s, l, x) \
   do { \
       if (l <= s->sc_bmx280debug) \
           printf x; \
   } while (/*CONSTCOND*/0)
#else
#define DPRINTF(s, l, x)
#endif

CFATTACH_DECL_NEW(bmx280thpi2c, sizeof(struct bmx280_sc),
   bmx280thpi2c_match, bmx280thpi2c_attach, bmx280thpi2c_detach, NULL);

/* For the BMX280, a read consists of writing on the I2C bus
* a I2C START, I2C SLAVE address, then the starting register.
* If that works, then following will be another I2C START,
* I2C SLAVE address, followed by as many I2C reads that is
* desired and then a I2C STOP
*/

static int
bmx280thpi2c_read_register_direct(i2c_tag_t tag, i2c_addr_t addr, uint8_t reg,
   uint8_t *buf, size_t blen)
{
       int error;

       error = iic_exec(tag,I2C_OP_WRITE,addr,&reg,1,NULL,0,0);

       if (error == 0) {
               error = iic_exec(tag,I2C_OP_READ_WITH_STOP,addr,NULL,0,
                   buf,blen,0);
       }

       return error;
}

static int
bmx280thpi2c_read_register(struct bmx280_sc *sc, uint8_t reg,
   uint8_t *buf, size_t blen)
{
       int error;

       KASSERT(blen > 0);

       error = bmx280thpi2c_read_register_direct(sc->sc_tag, sc->sc_addr, reg,
           buf, blen);

       return error;
}

/* For the BMX280, a write consists of sending a I2C START, I2C SLAVE
* address and then pairs of registers and data until a I2C STOP is
* sent.
*/

static int
bmx280thpi2c_write_register(struct bmx280_sc *sc,
   uint8_t *buf, size_t blen)
{
       int error;

       KASSERT(blen > 0);
       /* XXX - there should be a KASSERT for blen at least
          being an even number */

       error = iic_exec(sc->sc_tag,I2C_OP_WRITE_WITH_STOP,sc->sc_addr,NULL,0,
           buf,blen,0);

       return error;
}

static int
bmx280thpi2c_acquire_bus(struct bmx280_sc *sc)
{
       return(iic_acquire_bus(sc->sc_tag, 0));
}

static void
bmx280thpi2c_release_bus(struct bmx280_sc *sc)
{
       iic_release_bus(sc->sc_tag, 0);
}

static int
bmx280thpi2c_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug)
{
       uint8_t reg = BMX280_REGISTER_ID;
       uint8_t buf[1];
       int error;

       error = bmx280thpi2c_read_register_direct(tag, addr, reg, buf, 1);
       if (matchdebug) {
               printf("poke X 1: %d\n", error);
       }
       return error;
}

static int
bmx280thpi2c_match(device_t parent, cfdata_t match, void *aux)
{
       struct i2c_attach_args *ia = aux;
       int error, match_result;
       const bool matchdebug = false;

       if (iic_use_direct_match(ia, match, NULL, &match_result))
               return match_result;

       /* indirect config - check for configured address */
       if (ia->ia_addr != BMX280_TYPICAL_ADDR_1 &&
           ia->ia_addr != BMX280_TYPICAL_ADDR_2)
               return 0;

       /*
        * Check to see if something is really at this i2c address. This will
        * keep phantom devices from appearing
        */
       if (iic_acquire_bus(ia->ia_tag, 0) != 0) {
               if (matchdebug)
                       printf("in match acquire bus failed\n");
               return 0;
       }

       error = bmx280thpi2c_poke(ia->ia_tag, ia->ia_addr, matchdebug);
       iic_release_bus(ia->ia_tag, 0);

       return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0;
}

static void
bmx280thpi2c_attach(device_t parent, device_t self, void *aux)
{
       struct bmx280_sc *sc;
       struct i2c_attach_args *ia;

       ia = aux;
       sc = device_private(self);

       sc->sc_dev = self;
       sc->sc_tag = ia->ia_tag;
       sc->sc_addr = ia->ia_addr;
       sc->sc_bmx280debug = 0;
       sc->sc_func_acquire_bus = &bmx280thpi2c_acquire_bus;
       sc->sc_func_release_bus = &bmx280thpi2c_release_bus;
       sc->sc_func_read_register = &bmx280thpi2c_read_register;
       sc->sc_func_write_register = &bmx280thpi2c_write_register;

       mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);

       bmx280_attach(sc);

       return;
}

static int
bmx280thpi2c_detach(device_t self, int flags)
{
       struct bmx280_sc *sc;

       sc = device_private(self);

       mutex_enter(&sc->sc_mutex);

       /* Remove the sensors */
       if (sc->sc_sme != NULL) {
               sysmon_envsys_unregister(sc->sc_sme);
               sc->sc_sme = NULL;
       }
       mutex_exit(&sc->sc_mutex);

       /* Remove the sysctl tree */
       sysctl_teardown(&sc->sc_bmx280log);

       /* Remove the mutex */
       mutex_destroy(&sc->sc_mutex);

       return 0;
}

MODULE(MODULE_CLASS_DRIVER, bmx280thpi2c, "iic,bmx280thp");

#ifdef _MODULE
/* Like other drivers, we do this because the bmx280 common
* driver has the definitions already.
*/
#undef  CFDRIVER_DECL
#define CFDRIVER_DECL(name, class, attr)
#include "ioconf.c"
#endif

static int
bmx280thpi2c_modcmd(modcmd_t cmd, void *opaque)
{

       switch (cmd) {
       case MODULE_CMD_INIT:
#ifdef _MODULE
               return config_init_component(cfdriver_ioconf_bmx280thpi2c,
                   cfattach_ioconf_bmx280thpi2c, cfdata_ioconf_bmx280thpi2c);
#else
               return 0;
#endif
       case MODULE_CMD_FINI:
#ifdef _MODULE
               return config_fini_component(cfdriver_ioconf_bmx280thpi2c,
                     cfattach_ioconf_bmx280thpi2c, cfdata_ioconf_bmx280thpi2c);
#else
               return 0;
#endif
       default:
               return ENOTTY;
       }
}

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