3c08673438
These feature are required for an upcoming Apple MacBook topcase (HID over SPI) driver: A delay after toggling CS is required to avoid anomalies like an extra junk byte in front of the message. Keeping CS asserted is required to be able to read a status report after writing a command. (The device won't return the status if CS was deasserted.) Sleep is not allowed in the interrupt context where the Apple input driver runs its transactions. Use a flag to tell the SPI driver to avoid mtx_sleep. Reviewed by: manu (ok to SPI part of larger patch) MFC afret: 1 month Differential revision: https://reviews.freebsd.org/D29534
80 lines
2.6 KiB
C
80 lines
2.6 KiB
C
/*-
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* Copyright (c) 2006 M. Warner Losh <imp@FreeBSD.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#define SPIBUS_IVAR(d) (struct spibus_ivar *) device_get_ivars(d)
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#define SPIBUS_SOFTC(d) (struct spibus_softc *) device_get_softc(d)
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struct spibus_softc
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{
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device_t dev;
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};
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#define SPIBUS_MODE_NONE 0
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#define SPIBUS_MODE_CPHA 1
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#define SPIBUS_MODE_CPOL 2
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#define SPIBUS_MODE_CPOL_CPHA 3
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struct spibus_ivar
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{
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uint32_t cs;
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uint32_t mode;
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uint32_t clock;
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uint32_t cs_delay;
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struct resource_list rl;
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};
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#define SPIBUS_CS_HIGH (1U << 31)
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enum {
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SPIBUS_IVAR_CS, /* chip select that we're on */
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SPIBUS_IVAR_MODE, /* SPI mode (0-3) */
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SPIBUS_IVAR_CLOCK, /* maximum clock freq for device */
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SPIBUS_IVAR_CS_DELAY, /* delay in microseconds after toggling chip select */
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};
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#define SPIBUS_ACCESSOR(A, B, T) \
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static inline int \
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spibus_get_ ## A(device_t dev, T *t) \
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{ \
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return BUS_READ_IVAR(device_get_parent(dev), dev, \
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SPIBUS_IVAR_ ## B, (uintptr_t *) t); \
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} \
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static inline int \
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spibus_set_ ## A(device_t dev, T t) \
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{ \
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return BUS_WRITE_IVAR(device_get_parent(dev), dev, \
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SPIBUS_IVAR_ ## B, (uintptr_t) t); \
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}
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SPIBUS_ACCESSOR(cs, CS, uint32_t)
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SPIBUS_ACCESSOR(mode, MODE, uint32_t)
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SPIBUS_ACCESSOR(clock, CLOCK, uint32_t)
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SPIBUS_ACCESSOR(cs_delay, CS_DELAY, uint32_t)
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extern driver_t spibus_driver;
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extern driver_t ofw_spibus_driver;
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