#!/usr/bin/perl

# List or modify the GPIO pins on BeagleBone Black
#
# "bbpins.pl" for help
#
# CSV data derived from Derek Molloy's pin spreadsheet
#
# This code is in the public domain

use strict;
use Text::CSV;

my $base = 0x44e10000;
my $gpiobase = "/sys/class/gpio/gpio";
my $ctrlfile = "/sys/class/gpio/";
my $muxfile = "/sys/kernel/debug/pinctrl/44e10800.pinmux/pins";

my $csv = Text::CSV->new();
my $data = <<EOD;
P8_01,,,,DGND,,,,,,,,,,
P8_02,,,,DGND,,,,,,,,,,
P8_03,6,0x818/018,38,GPIO1_6,gpio1[6],,,,,,mmc1_dat6,gpmc_ad6,R9,Used on Board (Group: pinmux_emmc2_pins)
P8_04,7,0x81c/01c,39,GPIO1_7,gpio1[7],,,,,,mmc1_dat7,gpmc_ad7,T9,Used on Board (Group: pinmux_emmc2_pins)
P8_05,2,0x808/008,34,GPIO1_2,gpio1[2],,,,,,mmc1_dat2,gpmc_ad2,R8,Used on Board (Group: pinmux_emmc2_pins)
P8_06,3,0x80c/00c,35,GPIO1_3,gpio1[3],,,,,,mmc1_dat3,gpmc_ad3,T8,Used on Board (Group: pinmux_emmc2_pins)
P8_07,36,0x890/090,66,TIMER4,gpio2[2],,,,,timer4,,gpmc_advn_ale,R7,
P8_08,37,0x894/094,67,TIMER7,gpio2[3],,,,,timer7,,gpmc_oen_ren,T7,
P8_09,39,0x89c/09c,69,TIMER5,gpio2[5],,,,,timer5,,gpmc_be0n_cle,T6,
P8_10,38,0x898/098,68,TIMER6,gpio2[4],,,,,timer6,,gpmc_wen,U6,
P8_11,13,0x834/034,45,GPIO1_13,gpio1[13],,,eQEP2B_in,mmc2_dat1,mmc1_dat5,lcd_data18,gpmc_ad13,R12,
P8_12,12,0x830/030,44,GPIO1_12,gpio1[12],,,EQEP2A_IN,MMC2_DAT0,MMC1_DAT4,LCD_DATA19,GPMC_AD12,T12,
P8_13,9,0x824/024,23,EHRPWM2B,gpio0[23],,,ehrpwm2B,mmc2_dat5,mmc1_dat1,lcd_data22,gpmc_ad9,T10,
P8_14,10,0x828/028,26,GPIO0_26,gpio0[26],,,ehrpwm2_tripzone_in,mmc2_dat6,mmc1_dat2,lcd_data21,gpmc_ad10,T11,
P8_15,15,0x83c/03c,47,GPIO1_15,gpio1[15],,,eQEP2_strobe,mmc2_dat3,mmc1_dat7,lcd_data16,gpmc_ad15,U13,
P8_16,14,0x838/038,46,GPIO1_14,gpio1[14],,,eQEP2_index,mmc2_dat2,mmc1_dat6,lcd_data17,gpmc_ad14,V13,
P8_17,11,0x82c/02c,27,GPIO0_27,gpio0[27],,,ehrpwm0_synco,mmc2_dat7,mmc1_dat3,lcd_data20,gpmc_ad11,U12,
P8_18,35,0x88c/08c,65,GPIO2_1,gpio2[1],mcasp0_fsr,,,mmc2_clk,gpmc_wait1,lcd_memory_clk,gpmc_clk_mux0,V12,
P8_19,8,0x820/020,22,EHRPWM2A,gpio0[22],,,ehrpwm2A,mmc2_dat4,mmc1_dat0,lcd_data23,gpmc_ad8,U10,
P8_20,33,0x884/084,63,GPIO1_31,gpio1[31],,,,,mmc1_cmd,gpmc_be1n,gpmc_csn2,V9,Used on Board (Group: pinmux_emmc2_pins)
P8_21,32,0x880/080,62,GPIO1_30,gpio1[30],,,,,mmc1_clk,gpmc_clk,gpmc_csn1,U9,Used on Board (Group: pinmux_emmc2_pins)
P8_22,5,0x814/014,37,GPIO1_5,gpio1[5],,,,,,mmc1_dat5,gpmc_ad5,V8,Used on Board (Group: pinmux_emmc2_pins)
P8_23,4,0x810/010,36,GPIO1_4,gpio1[4],,,,,,mmc1_dat4,gpmc_ad4,U8,Used on Board (Group: pinmux_emmc2_pins)
P8_24,1,0x804/004,33,GPIO1_1,gpio1[1],,,,,,mmc1_dat1,gpmc_ad1,V7,Used on Board (Group: pinmux_emmc2_pins)
P8_25,0,0x800/000,1,GPIO1_0,gpio1[0],,,,,,mmc1_dat0,gpmc_ad0,U7,Used on Board (Group: pinmux_emmc2_pins)
P8_26,31,0x87c/07c,61,GPIO1_29,gpio1[29],,,,,,,gpmc_csn0,V6,
P8_27,56,0x8e0/0e0,86,GPIO2_22,gpio2[22],,,,,,gpmc_a8,lcd_vsync,U5,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_28,58,0x8e8/0e8,88,GPIO2_24,gpio2[24],,,,,,gpmc_a10,lcd_pclk,V5,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_29,57,0x8e4/0e4,87,GPIO2_23,gpio2[23],,,,,,gpmc_a9,lcd_hsync,R5,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_30,59,0x8ec/0ec,89,GPIO2_25,gpio2[25],,,,,,gpmc_a11,lcd_ac_bias_en,R6,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_31,54,0x8d8/0d8,10,UART5_CTSN,gpio0[10],uart5_ctsn,,uart5_rxd,mcasp0_axr1,eQEP1_index,gpmc_a18,lcd_data14,V4,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_32,55,0x8dc/0dc,11,UART5_RTSN,gpio0[11],uart5_rtsn,,mcasp0_axr3,mcasp0_ahclkx,eQEP1_strobe,gpmc_a19,lcd_data15,T5,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_33,53,0x8d4/0d4,9,UART4_RTSN,gpio0[9],uart4_rtsn,,mcasp0_axr3,mcasp0_fsr,eQEP1B_in,gpmc_a17,lcd_data13,V3,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_34,51,0x8cc/0cc,81,UART3_RTSN,gpio2[17],uart3_rtsn,,mcasp0_axr2,mcasp0_ahclkr,ehrpwm1B,gpmc_a15,lcd_data11,U4,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_35,52,0x8d0/0d0,8,UART4_CTSN,gpio0[8],uart4_ctsn,,mcasp0_axr2,mcasp0_aclkr,eQEP1A_in,gpmc_a16,lcd_data12,V2,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_36,50,0x8c8/0c8,80,UART3_CTSN,gpio2[16],uart3_ctsn,,,mcasp0_axr0,ehrpwm1A,gpmc_a14,lcd_data10,U3,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_37,48,0x8c0/0c0,78,UART5_TXD,gpio2[14],uart2_ctsn,,uart5_txd,mcasp0_aclkx,ehrpwm1_tripzone_in,gpmc_a12,lcd_data8,U1,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_38,49,0x8c4/0c4,79,UART5_RXD,gpio2[15],uart2_rtsn,,uart5_rxd,mcasp0_fsx,ehrpwm0_synco,gpmc_a13,lcd_data9,U2,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_39,46,0x8b8/0b8,76,GPIO2_12,gpio2[12],,,,eQEP2_index,,gpmc_a6,lcd_data6,T3,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_40,47,0x8bc/0bc,77,GPIO2_13,gpio2[13],,,pr1_edio_data_out7,eQEP2_strobe,,gpmc_a7,lcd_data7,T4,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_41,44,0x8b0/0b0,74,GPIO2_10,gpio2[10],,,,eQEP2A_in,,gpmc_a4,lcd_data4,T1,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_42,45,0x8b4/0b4,75,GPIO2_11,gpio2[11],,,,eQEP2B_in,,gpmc_a5,lcd_data5,T2,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_43,42,0x8a8/0a8,72,GPIO2_8,gpio2[8],,,,ehrpwm2_tripzone_in,,gpmc_a2,lcd_data2,R3,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_44,43,0x8ac/0ac,73,GPIO2_9,gpio2[9],,,,ehrpwm0_synco,,gpmc_a3,lcd_data3,R4,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_45,40,0x8a0/0a0,70,GPIO2_6,gpio2[6],,,,ehrpwm2A,,gpmc_a0,lcd_data0,R1,Allocated (Group: nxp_hdmi_bonelt_pins)
P8_46,41,0x8a4/0a4,71,GPIO2_7,gpio2[7],,,,ehrpwm2B,,gpmc_a1,lcd_data1,R2,Allocated (Group: nxp_hdmi_bonelt_pins)
P9_01,,,,GND,,,,,,,,,,Ground
P9_02,,,,GND,,,,,,,,,,Ground
P9_03,,,,DC_3.3V,,,,,,,,,,
P9_04,,,,DC_3.3V,,,,,,,,,,250mA Max Current
P9_05,,,,VDD_5V,,,,,,,,,,
P9_06,,,,VDD_5V,,,,,,,,,,1A Max Current (only if DC jack powered)
P9_07,,,,SYS_5V,,,,,,,,,,250mA Max Current
P9_08,,,,SYS_5V,,,,,,,,,,250mA Max Current
P9_09,,,,PWR_BUT,,,,,,,,,,Has a 5V Level (pulled up by TP65217C)
P9_10,,,,SYS_RESETn,,,,,,,,RESET_OUT,A10,
P9_11,28,0x870/070,30,UART4_RXD,gpio0[30],uart4_rxd_mux2,,mmc1_sdcd,rmii2_crs_dv,gpmc_csn4,mii2_crs,gpmc_wait0,T17,NB: GPIOs limit current to 4-6mA output and approx. 8mA on input
P9_12,30,0x878/078,60,GPIO1_28,gpio1[28],mcasp0_aclkr_mux3,,gpmc_dir,mmc2_dat3,gpmc_csn6,mii2_col,gpmc_be1n,U18,
P9_13,29,0x874/074,31,UART4_TXD,gpio0[31],uart4_txd_mux2,,mmc2_sdcd,rmii2_rxerr,gpmc_csn5,mii2_rxerr,gpmc_wpn,U17,
P9_14,18,0x848/048,50,EHRPWM1A,gpio1[18],ehrpwm1A_mux1,,gpmc_a18,mmc2_dat1,rgmii2_td3,mii2_txd3,gpmc_a2,U14,
P9_15,16,0x840/040,48,GPIO1_16,gpio1[16],ehrpwm1_tripzone_input,,gpmc_a16,mii2_txen,rmii2_tctl,gmii2_txen,gpmc_a0,R13,
P9_16,19,0x84c/04c,51,EHRPWM1B,gpio1[19],ehrpwm1B_mux1,,gpmc_a19,mmc2_dat2,rgmii2_td2,mii2_txd2,gpmc_a3,T14,
P9_17,87,0x95c/15c,5,I2C1_SCL,gpio0[5],,,,ehrpwm0_synci,I2C1_SCL,mmc2_sdwp,spi0_cs0,A16,
P9_18,86,0x958/158,4,I2C1_SDA,gpio0[4],,,,ehrpwm0_tripzone,I2C1_SDA,mmc1_sdwp,spi0_d1,B16,
P9_19,95,0x97c/17c,13,I2C2_SCL,gpio0[13],,,spi1_cs1,I2C2_SCL,dcan0_rx,timer5,uart1_rtsn,D17,Allocated (Group: pinmux_i2c2_pins)
P9_20,94,0x978/178,12,I2C2_SDA,gpio0[12],,,spi1_cs0,I2C2_SDA,dcan0_tx,timer6,uart1_ctsn,D18,Allocated (Group: pinmux_i2c2_pins)
P9_21,85,0x954/154,3,UART2_TXD,gpio0[3],EMU3_mux1,,,ehrpwm0B,I2C2_SCL,uart2_txd,spi0_d0,B17,
P9_22,84,0x950/150,2,UART2_RXD,gpio0[2],EMU2_mux1,,,ehrpwm0A,I2C2_SDA,uart2_rxd,spi0_sclk,A17,
P9_23,17,0x844/044,49,GPIO1_17,gpio1[17],ehrpwm0_synco,,gpmc_a17,mmc2_dat0,rgmii2_rxdv,gmii2_rxdv,gpmc_a1,V14,
P9_24,97,0x984/184,15,UART1_TXD,gpio0[15],,,,I2C1_SCL,dcan1_rx,mmc2_sdwp,uart1_txd,D15,
P9_25,107,0x9ac/1ac,117,GPIO3_21,gpio3[21],,,EMU4_mux2,mcasp1_axr1,mcasp0_axr3,eQEP0_strobe,mcasp0_ahclkx,A14,Allocated (Group: mcasp0_pins)
P9_26,96,0x980/180,14,UART1_RXD,gpio0[14],,,,I2C1_SDA,dcan1_tx,mmc1_sdwp,uart1_rxd,D16,
P9_27,105,0x9a4/1a4,115,GPIO3_19,gpio3[19],,,EMU2_mux2,mcasp1_fsx,mcasp0_axr3,eQEP0B_in,mcasp0_fsr,C13,
P9_28,103,0x99c/19c,113,SPI1_CS0,gpio3[17],,,eCAP2_in_PWM2_out,spi1_cs0,mcasp0_axr2,ehrpwm0_synci,mcasp0_ahclkr,C12,Allocated (Group: mcasp0_pins)
P9_29,101,0x994/194,111,SPI1_D0,gpio3[15],,,mmc1_sdcd_mux1,spi1_d0,,ehrpwm0B,mcasp0_fsx,B13,Allocated (Group: mcasp0_pins)
P9_30,102,0x998/198,112,SPI1_D1,gpio3[16],,,mmc2_sdcd_mux1,spi1_d1,,ehrpwm0_tripzone,mcasp0_axr0,D12,
P9_31,100,0x990/190,110,SPI1_SCLK,gpio3[14],,,mmc0_sdcd_mux1,spi1_sclk,,ehrpwm0A,mcasp0_aclkx,A13,Allocated (Group: mcasp0_pins)
P9_32,,,,VADC,,,,,,,,,,Voltage Reference for ADC (NB:1.8V)
P9_33,,,,AIN4,,,,,,,,,C8,NB: 1.8V tolerant
P9_34,,,,AGND,,,,,,,,,,Ground for ADC
P9_35,,,,AIN6,,,,,,,,,A8,NB: 1.8V tolerant
P9_36,,,,AIN5,,,,,,,,,B8,NB: 1.8V tolerant
P9_37,,,,AIN2,,,,,,,,,B7,NB: 1.8V tolerant
P9_38,,,,AIN3,,,,,,,,,A7,NB: 1.8V tolerant
P9_39,,,,AIN0,,,,,,,,,B6,NB: 1.8V tolerant
P9_40,,,,AIN1,,,,,,,,,C7,NB: 1.8V tolerant
P9_41A,109,0x9b4/1b4,20,CLKOUT2,gpio0[20],EMU3_mux0,,timer7_mux1,clkout2,tclkin,,xdma_event_intr1,D14,Both signals are connected to P21 of P11
P9_41B,,0x9a8/1a8,116,GPIO3_20,gpio3[20],,,emu3,Mcasp1_axr0,,eQEP0_index,mcasp0_axr1,D13,Both signals are connected to P21 of P11
P9_42A,89,0x964/164,7,GPIO0_7,gpio0[7],xdma_event_intr2,mmc0_sdwp,spi1_sclk,pr1_ecap0_ecap_capin_apwm_o,spi1_cs1,uart3_txd,eCAP0_in_PWM0_out,C18,Both signals are connected to P21 of P11
P9_42B,,0x9a0/1a0,114,GPIO3_18,gpio3[18],,,,Mcasp1_aclkx,Mcaspo_axr2,eQEP0A_in,Mcasp0_aclkr,B12,Both signals are connected to P21 of P11
P9_43,,,,GND,,,,,,,,,,See pg 50 of the SRM
P9_44,,,,GND,,,,,,,,,,Ground
P9_45,,,,GND,,,,,,,,,,Ground
P9_46,,,,GND,,,,,,,,,,Ground
EOD
my %pinbyheadname = {};
my %pinbyname = {};
my %pinbyaddr = {};
my %pinbymode = {};
my %pinbycurrentmode = {};
foreach (split(/\n/, $data)) {
    if ($csv->parse($_)) {
        my @col = $csv->fields();
        my $pin = {};
        $pin->{headname} = $col[0] if $col[0];
        $pin->{pin} = $col[1] if $col[1];
        if ($col[2]) {
            $col[2] =~ s/(0x...).*/$1/;
            $pin->{addr} = $base + hex($col[2]);
        }
        $pin->{gpio} = $col[3] if $col[3];
        $pin->{name} = $col[4] if $col[4];
        $pin->{m7} = lc $col[5] if $col[5];
        $pin->{m6} = lc $col[6] if $col[6];
        $pin->{m5} = lc $col[7] if $col[7];
        $pin->{m4} = lc $col[8] if $col[8];
        $pin->{m3} = lc $col[9] if $col[9];
        $pin->{m2} = lc $col[10] if $col[10];
        $pin->{m1} = lc $col[11] if $col[11];
        $pin->{m0} = lc $col[12] if $col[12];
        $pin->{chippin} = $col[13] if $col[13];
        $pin->{comment} = $col[14] if $col[14];
        $pinbyheadname{$pin->{headname}} = $pin if $pin->{headname};
        $pinbyname{$pin->{name}} = $pin if $pin->{name};
        $pinbyaddr{$pin->{addr}} = $pin if $pin->{addr};
        foreach my $mode ("m0","m1","m2","m3","m4","m5","m6","m7") {
            if ($pin->{$mode}) {
                my $modename = $pin->{$mode};
                my @pinlist;
                my @pinlist = ();
                @pinlist = @{$pinbymode{$modename}} if (exists $pinbymode{$modename});
                push (@pinlist, $pin);
                $pinbymode{$modename} = \@pinlist;
            }
        }
    } else {
        my $err = $csv->error_input;
        print "Failed to parse line: $err";
    }
}
open(MUXSTATE, $muxfile) || die "$muxfile: $!";
while (<MUXSTATE>) {
    my ($pinix, $address, $muxstate) = /^pin (\d+) \(([a-z0-9]*)\) (\d+)/;
    $address = hex($address);
    $muxstate = hex($muxstate);
    if (exists $pinbyaddr{$address}) {
        my $pin = $pinbyaddr{$address};
        $pin->{intpin} = $pinix;
        $pin->{muxstate} = $muxstate;
        $pin->{currentmode} = $pin->{sprintf("m%d", $pin->{muxstate}&7)};
        $pinbycurrentmode{$pin->{currentmode}} = $pin;
        if ($pin->{currentmode} =~ /^gpio/) {
            $pin->{gpiofile} = sprintf("%s%d", $gpiobase, $pin->{gpio});
            my $state = "";
            if (-d $pin->{gpiofile}) {
                open (FD, sprintf("%s/direction", $pin->{gpiofile})) || die "direction: $!";
                my $line = <FD>;
                close FD;
                ($state = $line) =~ s/\n//g;
            } else {
                if (($pin->{muxstate} & 0x20) == 0) {
                    $state = "[out]";
                } else {
                    $state = "[in]";
                }
            }
            if ($state =~ /in/) {
                if (($pin->{muxstate} & 0x8) == 0) {
                    if (($pin->{muxstate} & 0x10) == 0) {
                        $state = "$state [pulldown]";
                    } else {
                        $state = "$state [pullup]";
                    }
                }
            }
            if (($pin->{muxstate} & 0x40) == 0) {
                $state = "$state [fast]";
            } else {
                $state = "$state [slow]";
            }
            $pin->{gpiostate} = $state;
        }
    }
}
close MUXSTATE;

if ($ARGV[0] eq "list") {
    printf("%-7s %-6s %-12s %-20s %-20s\n", "HEADER", "GPIO", "NAME", "CURRENT-MODE", "GPIO-STATE");
    foreach $_ (sort keys %pinbyheadname) {
        my $pin = $pinbyheadname{$_};
        printf("%-7s %-6d %-12s %-20s %-20s\n", $pin->{headname}, $pin->{gpio}, $pin->{name}, $pin->{currentmode}, $pin->{gpiostate});
    }
} elsif ($ARGV[0] eq "find") {
#    print join(",", sort keys %pinbymode);
    my @list = ();
    push (@list, $pinbyheadname{uc $ARGV[1]}) if exists $pinbyheadname{uc $ARGV[1]};
    push (@list, $pinbyname{uc $ARGV[1]}) if exists $pinbyname{uc $ARGV[1]};
    push (@list, @{$pinbymode{lc $ARGV[1]}}) if exists $pinbymode{lc $ARGV[1]};
    my %dup = ();
    printf("%-7s %-6s %-12s %-20s %s\n", "HEADER", "GPIO", "NAME", "CURRENT-MODE", "OTHER-MODES");
    foreach my $pin (@list) {
        unless (exists $dup{$pin->{headname}}) {
            printf("%-7s %-6d %-12s %-20s", $pin->{headname}, $pin->{gpio}, $pin->{name}, $pin->{currentmode});
            foreach my $mode ("m0","m1","m2","m3","m4","m5","m6","m7") {
                if (exists $pin->{$mode} && $pin->{currentmode} ne $pin->{$mode}) {
                    printf(" %s", $pin->{$mode});
                }
            }
            printf("\n");

            $dup{$pin->{headname}} = $pin;
        }
    }
    if ($#list < 0) {
        printf("No such pin: %s\n", $ARGV[1]);
    }
} elsif ($ARGV[0] eq "setgpio") {
    my $pin = $pinbyheadname{uc $ARGV[1]} ;
    if (!defined($pin)) {
        $pin = $pinbycurrentmode{lc $ARGV[1]};
    }
    if (!defined($pin)) {
        printf("No such pin: %s\n", $ARGV[1]);
    } elsif ($pin->{currentmode} !~ /^gpio/) {
        printf("Not a GPIO pin: %s mode is %s\n", $ARGV[1], $pin->{currentmode});
    } else {
        my $pinnum = $pin->{gpio};
        my $pinfile = $pin->{gpiofile};
        if ($ARGV[2] eq "in") {
            if (!-f $pinfile) {
                open (FD, ">$ctrlfile/export") || die "$ctrlfile/export: $1";
                print FD "$pinnum\n";
                close FD;
            }
            open (FD, ">$pinfile/direction") || die "$pinfile/direction: $!";
            print FD "in\n";
            close FD;
        } elsif ($ARGV[2] eq "out") {
            if (!-f $pinfile) {
                open (FD, ">$ctrlfile/export") || die "$ctrlfile/export: $!";
                print FD "$pinnum\n";
                close FD;
            }
            open (FD, ">$pinfile/direction") || die "$pinfile/direction: $!";
            print FD "out\n";
            close FD;
            if ($ARGV[3] eq "0" || $ARGV[3] eq "1") {
                open (FD, ">$pinfile/value") || die "$pinfile/direction: $!";
                print FD "$ARGV[2]\n";
                close FD;
            }
        } elsif ($ARGV[2] eq "disable") {
            if (!$pinfile) {
                open (FD, ">$ctrlfile/unexport") || die "$ctrlfile/unexport: $!";
                print FD "$pinnum\n";
                close FD;
            }
        }
    }
} else {
    print<<EOF
Usage:

bbpins.pl list
        list the state of the pins, for example:
        P9_26   14    uart1_rxd            
        P9_27   115   gpio3[19]            [in] [pulldown] [fast]
        This shows the pin positions, the GPIO number, the name of the
        current pin mode, and for GPIO pins the GPIO state - input (with pullup/pulldown),
        output, and the slew mode (fast or slow). If the value is in
        square brackets, ie [input], it is derived from the pinmux file.
        Otherwise it is read directly from the enabled GPIO directory

bbpins.pl find <pinname>
        find the pins with the specified name, eg "find uart5_txd"

bbpins.pl gpio <pinname> [in|out|disable] [1|0]*
        set the specified pin to input, output or disabled. If output,
        the second argument can be 1 or 0 to set the state of the pin

EOF
}