1.\" 2.\" Copyright (c) 2019 Ian Lepore <ian@freebsd.org> 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd March 2, 2019 28.Dt AT45D 4 29.Os 30.Sh NAME 31.Nm at45d 32.Nd driver for DataFlash(tm) non-volatile storage devices 33.Sh SYNOPSIS 34To compile this driver into the kernel, 35place the following line in your 36kernel configuration file: 37.Bd -ragged -offset indent 38.Cd "device at45d" 39.Ed 40.Pp 41Alternatively, to load the driver as a 42module at boot time, place the following line in 43.Xr loader.conf 5 : 44.Bd -literal -offset indent 45at45d_load="YES" 46.Ed 47.Sh DESCRIPTION 48The 49.Nm 50driver provides support for the family of non-volatile storage 51devices known collectively as DataFlash(tm). 52DataFlash chips typically have part numbers beginning with AT45DB. 53The 54.Nm 55driver supports only the SPI bus versions of each AT45DB device, 56indicated by the last digit of the part number being 1 or 2. 57.Pp 58The 59.Nm 60driver uses opcode 0x9f to read the manufacturer and device ID 61data to determine whether the device is supported. 62The device ID is looked up using a table of data within the driver 63which describes the attributes of each supported device, 64such as block size, sector size, and device capacity. 65When a supported device is found, the 66.Nm 67driver creates a disk device and makes it accessible at 68.Pa /dev/flash/at45d? . 69The new disk device is then tasted by the available 70.Xr geom 4 71modules as with any disk device. 72.Sh HARDWARE 73The 74.Nm 75driver provides support for the following devices: 76.Pp 77.Bl -bullet -compact 78.It 79AT45DB011B 80.It 81AT45DB021B 82.It 83AT45DB041x 84.It 85AT45DB081B 86.It 87AT45DB161x 88.It 89AT45DB321x 90.It 91AT45DB321x 92.It 93AT45DB641E 94.It 95AT45DB642x 96.El 97.Sh FDT CONFIGURATION 98On an 99.Xr fdt 4 100based system, the 101.Nm 102device is defined as a slave device subnode 103of the SPI bus controller node. 104All properties documented in the 105.Va spibus.txt 106bindings document can be used with the 107.Nm 108device. 109The most commonly-used ones are documented below. 110.Pp 111The following properties are required in the 112.Nm 113device subnode: 114.Bl -tag -width indent 115.It Va compatible 116Must be the string "atmel,at45". 117.It Va reg 118Chip select address of device. 119.It Va spi-max-frequency 120The maximum bus frequency to use when communicating with this slave device. 121Actual bus speed may be lower, depending on the capabilities of the SPI 122bus controller hardware. 123.El 124.Pp 125The following properties are optional for the 126.Nm 127device subnode: 128.Bl -tag -width indent 129.It Va freebsd,sectorsize 130The sector size of the disk created for this storage device. 131It must be a multiple of the device's page size. 132The default is the device page size. 133.It Va spi-cpha 134Empty property indicating the slave device requires shifted clock 135phase (CPHA) mode. 136.It Va spi-cpol 137Empty property indicating the slave device requires inverse clock 138polarity (CPOL) mode. 139.It Va spi-cs-high 140Empty property indicating the slave device requires chip select active high. 141.El 142.Sh HINTS CONFIGURATION 143On a 144.Xr device.hints 5 145based system, such as 146.Li MIPS , 147these values are configurable for 148.Nm : 149.Bl -tag -width indent 150.It Va hint.at45d.%d.at 151The spibus the 152.Nm 153instance is attached to. 154.It Va hint.at45d.%d.clock 155The maximum bus frequency to use when communicating with this device. 156Actual bus speed may be lower, depending on the capabilities of the SPI 157bus controller hardware. 158.It Va hint.at45d.%d.cs 159The chip-select number to assert when performing I/O for this device. 160Set the high bit (1 << 31) to invert the logic level of the chip select line. 161.It Va hint.at45d.%d.mode 162The SPI mode (0-3) to use when communicating with this device. 163.It Va hint.at45d.%d.sectorsize 164The sector size of the disk created for this storage device. 165It must be a multiple of the device's page size. 166The default is the device page size. 167.El 168.Sh FILES 169.Bl -tag -width /dev/flash/at45d? 170.It Pa /dev/flash/at45d? 171Provides read/write access to the storage device. 172.It Pa /dev/flash/spi? 173An alias for the 174.Pa /dev/at45d? 175device, for backwards compatibility with older versions of the driver. 176.El 177.Sh SEE ALSO 178.Xr fdt 4 , 179.Xr geom 4 180.Sh HISTORY 181The 182.Nm 183driver first appeared in 184.Fx 6.0 . 185