iio: proximity: vl53l0x-i2c: claim direct mode for raw readsgrafted

vl53l0x_read_raw() starts a single-shot ranging measurement and reads
back the result. Once the triggered buffer is enabled the sensor runs in
continuous mode and its data-ready interrupt is routed to the trigger,
so a concurrent in_distance_raw read disturbs the streaming setup and
never gets its completion, returning -ETIMEDOUT.

The original submission claimed direct mode here, but it was dropped
during review because the driver had no buffer support at the time [1].
Continuous (buffered) mode was later added without restoring the
claim [2], reintroducing the conflict.

Reject direct reads while buffered capture is active by claiming direct
mode around the measurement, as the vl53l1x sibling already does.

Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support")
Link: https://lore.kernel.org/linux-iio/20180911160300.GA9212@himanshu-Vostro-3559/ [1]
Link: https://lore.kernel.org/linux-iio/20240909101508.263085-3-abhashkumarjha123@gmail.com/ [2]
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 205 insertions, 0 deletions

diff --git a/include/math-emu/double.h b/include/math-emu/double.h
new file mode 100644
index 000000000..655ccf1c4
--- /dev/null
+++ b/include/math-emu/double.h
@@ -0,0 +1,205 @@
+/* Software floating-point emulation.
+   Definitions for IEEE Double Precision
+   Copyright (C) 1997,1998,1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Richard Henderson (rth@cygnus.com),
+		  Jakub Jelinek (jj@ultra.linux.cz),
+		  David S. Miller (davem@redhat.com) and
+		  Peter Maydell (pmaydell@chiark.greenend.org.uk).
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, write to the Free Software Foundation, Inc.,
+   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifndef    __MATH_EMU_DOUBLE_H__
+#define    __MATH_EMU_DOUBLE_H__
+
+#if _FP_W_TYPE_SIZE < 32
+#error "Here's a nickel kid.  Go buy yourself a real computer."
+#endif
+
+#if _FP_W_TYPE_SIZE < 64
+#define _FP_FRACTBITS_D		(2 * _FP_W_TYPE_SIZE)
+#else
+#define _FP_FRACTBITS_D		_FP_W_TYPE_SIZE
+#endif
+
+#define _FP_FRACBITS_D		53
+#define _FP_FRACXBITS_D		(_FP_FRACTBITS_D - _FP_FRACBITS_D)
+#define _FP_WFRACBITS_D		(_FP_WORKBITS + _FP_FRACBITS_D)
+#define _FP_WFRACXBITS_D	(_FP_FRACTBITS_D - _FP_WFRACBITS_D)
+#define _FP_EXPBITS_D		11
+#define _FP_EXPBIAS_D		1023
+#define _FP_EXPMAX_D		2047
+
+#define _FP_QNANBIT_D		\
+	((_FP_W_TYPE)1 << (_FP_FRACBITS_D-2) % _FP_W_TYPE_SIZE)
+#define _FP_IMPLBIT_D		\
+	((_FP_W_TYPE)1 << (_FP_FRACBITS_D-1) % _FP_W_TYPE_SIZE)
+#define _FP_OVERFLOW_D		\
+	((_FP_W_TYPE)1 << _FP_WFRACBITS_D % _FP_W_TYPE_SIZE)
+
+#if _FP_W_TYPE_SIZE < 64
+
+union _FP_UNION_D
+{
+  double flt;
+  struct {
+#if __BYTE_ORDER == __BIG_ENDIAN
+    unsigned sign  : 1;
+    unsigned exp   : _FP_EXPBITS_D;
+    unsigned frac1 : _FP_FRACBITS_D - (_FP_IMPLBIT_D != 0) - _FP_W_TYPE_SIZE;
+    unsigned frac0 : _FP_W_TYPE_SIZE;
+#else
+    unsigned frac0 : _FP_W_TYPE_SIZE;
+    unsigned frac1 : _FP_FRACBITS_D - (_FP_IMPLBIT_D != 0) - _FP_W_TYPE_SIZE;
+    unsigned exp   : _FP_EXPBITS_D;
+    unsigned sign  : 1;
+#endif
+  } bits __attribute__((packed));
+};
+
+#define FP_DECL_D(X)		_FP_DECL(2,X)
+#define FP_UNPACK_RAW_D(X,val)	_FP_UNPACK_RAW_2(D,X,val)
+#define FP_UNPACK_RAW_DP(X,val)	_FP_UNPACK_RAW_2_P(D,X,val)
+#define FP_PACK_RAW_D(val,X)	_FP_PACK_RAW_2(D,val,X)
+#define FP_PACK_RAW_DP(val,X)		\
+  do {					\
+    if (!FP_INHIBIT_RESULTS)		\
+      _FP_PACK_RAW_2_P(D,val,X);	\
+  } while (0)
+
+#define FP_UNPACK_D(X,val)		\
+  do {					\
+    _FP_UNPACK_RAW_2(D,X,val);		\
+    _FP_UNPACK_CANONICAL(D,2,X);	\
+  } while (0)
+
+#define FP_UNPACK_DP(X,val)		\
+  do {					\
+    _FP_UNPACK_RAW_2_P(D,X,val);	\
+    _FP_UNPACK_CANONICAL(D,2,X);	\
+  } while (0)
+
+#define FP_PACK_D(val,X)		\
+  do {					\
+    _FP_PACK_CANONICAL(D,2,X);		\
+    _FP_PACK_RAW_2(D,val,X);		\
+  } while (0)
+
+#define FP_PACK_DP(val,X)		\
+  do {					\
+    _FP_PACK_CANONICAL(D,2,X);		\
+    if (!FP_INHIBIT_RESULTS)		\
+      _FP_PACK_RAW_2_P(D,val,X);	\
+  } while (0)
+
+#define FP_ISSIGNAN_D(X)		_FP_ISSIGNAN(D,2,X)
+#define FP_NEG_D(R,X)			_FP_NEG(D,2,R,X)
+#define FP_ADD_D(R,X,Y)			_FP_ADD(D,2,R,X,Y)
+#define FP_SUB_D(R,X,Y)			_FP_SUB(D,2,R,X,Y)
+#define FP_MUL_D(R,X,Y)			_FP_MUL(D,2,R,X,Y)
+#define FP_DIV_D(R,X,Y)			_FP_DIV(D,2,R,X,Y)
+#define FP_SQRT_D(R,X)			_FP_SQRT(D,2,R,X)
+#define _FP_SQRT_MEAT_D(R,S,T,X,Q)	_FP_SQRT_MEAT_2(R,S,T,X,Q)
+
+#define FP_CMP_D(r,X,Y,un)	_FP_CMP(D,2,r,X,Y,un)
+#define FP_CMP_EQ_D(r,X,Y)	_FP_CMP_EQ(D,2,r,X,Y)
+
+#define FP_TO_INT_D(r,X,rsz,rsg)	_FP_TO_INT(D,2,r,X,rsz,rsg)
+#define FP_TO_INT_ROUND_D(r,X,rsz,rsg)	_FP_TO_INT_ROUND(D,2,r,X,rsz,rsg)
+#define FP_FROM_INT_D(X,r,rs,rt)	_FP_FROM_INT(D,2,X,r,rs,rt)
+
+#define _FP_FRAC_HIGH_D(X)	_FP_FRAC_HIGH_2(X)
+#define _FP_FRAC_HIGH_RAW_D(X)	_FP_FRAC_HIGH_2(X)
+
+#else
+
+union _FP_UNION_D
+{
+  double flt;
+  struct {
+#if __BYTE_ORDER == __BIG_ENDIAN
+    unsigned sign : 1;
+    unsigned exp  : _FP_EXPBITS_D;
+    unsigned long frac : _FP_FRACBITS_D - (_FP_IMPLBIT_D != 0);
+#else
+    unsigned long frac : _FP_FRACBITS_D - (_FP_IMPLBIT_D != 0);
+    unsigned exp  : _FP_EXPBITS_D;
+    unsigned sign : 1;
+#endif
+  } bits __attribute__((packed));
+};
+
+#define FP_DECL_D(X)		_FP_DECL(1,X)
+#define FP_UNPACK_RAW_D(X,val)	_FP_UNPACK_RAW_1(D,X,val)
+#define FP_UNPACK_RAW_DP(X,val)	_FP_UNPACK_RAW_1_P(D,X,val)
+#define FP_PACK_RAW_D(val,X)	_FP_PACK_RAW_1(D,val,X)
+#define FP_PACK_RAW_DP(val,X)		\
+  do {					\
+    if (!FP_INHIBIT_RESULTS)		\
+      _FP_PACK_RAW_1_P(D,val,X);	\
+  } while (0)
+
+#define FP_UNPACK_D(X,val)		\
+  do {					\
+    _FP_UNPACK_RAW_1(D,X,val);		\
+    _FP_UNPACK_CANONICAL(D,1,X);	\
+  } while (0)
+
+#define FP_UNPACK_DP(X,val)		\
+  do {					\
+    _FP_UNPACK_RAW_1_P(D,X,val);	\
+    _FP_UNPACK_CANONICAL(D,1,X);	\
+  } while (0)
+
+#define FP_PACK_D(val,X)		\
+  do {					\
+    _FP_PACK_CANONICAL(D,1,X);		\
+    _FP_PACK_RAW_1(D,val,X);		\
+  } while (0)
+
+#define FP_PACK_DP(val,X)		\
+  do {					\
+    _FP_PACK_CANONICAL(D,1,X);		\
+    if (!FP_INHIBIT_RESULTS)		\
+      _FP_PACK_RAW_1_P(D,val,X);	\
+  } while (0)
+
+#define FP_ISSIGNAN_D(X)		_FP_ISSIGNAN(D,1,X)
+#define FP_NEG_D(R,X)			_FP_NEG(D,1,R,X)
+#define FP_ADD_D(R,X,Y)			_FP_ADD(D,1,R,X,Y)
+#define FP_SUB_D(R,X,Y)			_FP_SUB(D,1,R,X,Y)
+#define FP_MUL_D(R,X,Y)			_FP_MUL(D,1,R,X,Y)
+#define FP_DIV_D(R,X,Y)			_FP_DIV(D,1,R,X,Y)
+#define FP_SQRT_D(R,X)			_FP_SQRT(D,1,R,X)
+#define _FP_SQRT_MEAT_D(R,S,T,X,Q)	_FP_SQRT_MEAT_1(R,S,T,X,Q)
+
+/* The implementation of _FP_MUL_D and _FP_DIV_D should be chosen by
+   the target machine.  */
+
+#define FP_CMP_D(r,X,Y,un)	_FP_CMP(D,1,r,X,Y,un)
+#define FP_CMP_EQ_D(r,X,Y)	_FP_CMP_EQ(D,1,r,X,Y)
+
+#define FP_TO_INT_D(r,X,rsz,rsg)	_FP_TO_INT(D,1,r,X,rsz,rsg)
+#define FP_TO_INT_ROUND_D(r,X,rsz,rsg)	_FP_TO_INT_ROUND(D,1,r,X,rsz,rsg)
+#define FP_FROM_INT_D(X,r,rs,rt)	_FP_FROM_INT(D,1,X,r,rs,rt)
+
+#define _FP_FRAC_HIGH_D(X)	_FP_FRAC_HIGH_1(X)
+#define _FP_FRAC_HIGH_RAW_D(X)	_FP_FRAC_HIGH_1(X)
+
+#endif /* W_TYPE_SIZE < 64 */
+
+
+#endif /* __MATH_EMU_DOUBLE_H__ */