spi_software: Implementation of software spi

Signed-off-by: Matt Janus <FragginRight@variabl.es>
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2019-02-09 12:22:10 -05:00
parent 090cd930d9
commit 98ed462865
6 changed files with 200 additions and 20 deletions

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@ -680,6 +680,13 @@
# The pin corresponding to the AD5206 chip select line. This pin
# will be set to low at the start of SPI messages and raised to high
# after the message completes. This parameter must be provided.
#spi_bus:
#spi_speed:
#spi_software_sclk_pin:
#spi_software_mosi_pin:
#spi_software_miso_pin:
# These optional parameters allow one to customize the SPI settings
# used to communicate with the chip.
#channel_1:
#channel_2:
#channel_3:
@ -787,6 +794,13 @@
# The pin corresponding to the TMC2130 chip select line. This pin
# will be set to low at the start of SPI messages and raised to high
# after the message completes. This parameter must be provided.
#spi_bus:
#spi_speed:
#spi_software_sclk_pin:
#spi_software_mosi_pin:
#spi_software_miso_pin:
# These optional parameters allow one to customize the SPI settings
# used to communicate with the chip.
#microsteps:
# The number of microsteps to configure the driver to use. Valid
# values are 1, 2, 4, 8, 16, 32, 64, 128, 256. This parameter must
@ -908,6 +922,11 @@
#spi_speed: 2000000
# SPI bus frequency used to communicate with the TMC2660 stepper
# driver. The default is 2000000.
#spi_software_sclk_pin:
#spi_software_mosi_pin:
#spi_software_miso_pin:
# These optional parameters allow one to customize the SPI settings
# used to communicate with the chip.
#microsteps:
# The number of microsteps to configure the driver to use. Valid
# values are 1, 2, 4, 8, 16, 32, 64, 128, 256. This parameter must
@ -1043,8 +1062,15 @@
# provided when using an uc1701 display.
#cs_pin:
#dc_pin:
#spi_bus:
#spi_speed:
#spi_software_sclk_pin:
#spi_software_mosi_pin:
#spi_software_miso_pin:
# The pins connected to an ssd1306 type lcd when in "4-wire" spi
# mode. The default is to use i2c mode for ssd1306 displays.
# mode. The parameters that start with "spi_" are optional and they
# control the spi settings used to communicate with the chip. The
# default is to use i2c mode for ssd1306 displays.
#menu_root:
# Entry point for menu, root menu container name. If this parameter
# is not provided then default menu root is used. When provided
@ -1140,6 +1166,12 @@
#spi_speed: 4000000
# The SPI speed (in hz) to use when communicating with the chip.
# The default is 4000000.
#spi_bus:
#spi_software_sclk_pin:
#spi_software_mosi_pin:
#spi_software_miso_pin:
# These optional parameters allow one to customize the SPI settings
# used to communicate with the chip.
#sensor_pin:
# The chip select line for the sensor chip. This parameter must be
# provided.

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@ -12,22 +12,33 @@ import mcu
# Helper code for working with devices connected to an MCU via an SPI bus
class MCU_SPI:
def __init__(self, mcu, bus, pin, mode, speed, shutdown_seq):
def __init__(self, mcu, bus, pin, mode, speed, shutdown_seq, sw_pins=None):
self.mcu = mcu
shutdown_msg = "".join(["%02x" % (x,) for x in shutdown_seq])
self.oid = self.mcu.create_oid()
if pin is None:
self.config_msg = (
"config_spi_without_cs oid=%d bus=%d mode=%d rate=%d"
" shutdown_msg=%s" % (
self.oid, bus, mode, speed, shutdown_msg))
else:
if pin is not None:
# Set all CS pins high before first config_spi
self.mcu.add_config_cmd("set_digital_out pin=%s value=1" % (pin,))
self.config_msg = (
if sw_pins is not None:
software_spi_oid = self.mcu.create_oid()
self.config_msgs = [
"config_software_spi oid=%d sclk_pin=%s mosi_pin=%s miso_pin=%s"
" mode=%d rate=%d" % (
software_spi_oid, sw_pins[0], sw_pins[1], sw_pins[2],
mode, speed),
"config_spi_from_software oid=%d sw_oid=%d pin=%s"
" shutdown_msg=%s" % (
self.oid, software_spi_oid, pin, shutdown_msg)]
elif pin is None:
self.config_msgs = [
"config_spi_without_cs oid=%d bus=%d mode=%d rate=%d"
" shutdown_msg=%s" % (
self.oid, bus, mode, speed, shutdown_msg)]
else:
self.config_msgs = [
"config_spi oid=%d bus=%d pin=%s mode=%d rate=%d"
" shutdown_msg=%s" % (
self.oid, bus, pin, mode, speed, shutdown_msg))
self.oid, bus, pin, mode, speed, shutdown_msg)]
self.cmd_queue = self.mcu.alloc_command_queue()
self.mcu.register_config_callback(self.build_config)
self.spi_send_cmd = self.spi_transfer_cmd = None
@ -38,7 +49,8 @@ class MCU_SPI:
def get_command_queue(self):
return self.cmd_queue
def build_config(self):
self.mcu.add_config_cmd(self.config_msg)
for msg in self.config_msgs:
self.mcu.add_config_cmd(msg)
self.spi_send_cmd = self.mcu.lookup_command(
"spi_send oid=%c data=%*s", cq=self.cmd_queue)
self.spi_transfer_cmd = self.mcu.lookup_command(
@ -68,11 +80,24 @@ def MCU_SPI_from_config(config, mode, pin_option="cs_pin",
ppins.reset_pin_sharing(cs_pin_params)
pin = None
# Load bus parameters
speed = config.getint('spi_speed', default_speed, minval=100000)
bus = config.getint('spi_bus', 0, minval=0)
# Create MCU_SPI object
mcu = cs_pin_params['chip']
return MCU_SPI(mcu, bus, pin, mode, speed, shutdown_seq)
speed = config.getint('spi_speed', default_speed, minval=100000)
if config.get('spi_software_sclk_pin', None) is not None:
sw_pin_names = ['spi_software_%s_pin' % (name,)
for name in ['sclk', 'mosi', 'miso']]
sw_pin_params = [ppins.lookup_pin(config.get(name), share_type=name)
for name in sw_pin_names]
for pin_params in sw_pin_params:
if pin_params['chip'] != mcu:
raise ppins.error("%s: spi pins must be on same mcu" % (
config.get_name(),))
sw_pins = tuple([pin_params['pin'] for pin_params in sw_pin_params])
bus = None
else:
bus = config.getint('spi_bus', 0, minval=0)
sw_pins = None
# Create MCU_SPI object
return MCU_SPI(mcu, bus, pin, mode, speed, shutdown_seq, sw_pins)
######################################################################

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@ -7,4 +7,4 @@ src-$(CONFIG_HAVE_GPIO_SPI) += spicmds.c thermocouple.c
src-$(CONFIG_HAVE_GPIO_I2C) += i2ccmds.c
src-$(CONFIG_HAVE_GPIO_HARD_PWM) += pwmcmds.c
src-$(CONFIG_HAVE_GPIO_BITBANGING) += lcd_st7920.c lcd_hd44780.c buttons.c \
tmcuart.c
tmcuart.c spi_software.c

81
src/spi_software.c Normal file
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@ -0,0 +1,81 @@
// Software SPI emulation
//
// Copyright (C) 2019 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include "board/irq.h" // gpio_out_setup
#include "board/gpio.h" // gpio_out_setup
#include "basecmd.h" // oid_alloc
#include "command.h" // DECL_COMMAND
#include "sched.h" // sched_shutdown
struct spi_software {
struct gpio_out sclk, mosi;
struct gpio_in miso;
uint8_t mode;
};
void
command_config_software_spi(uint32_t *args)
{
uint8_t oid = args[0], sclk_pin = args[1], mosi_pin = args[2];
uint8_t miso_pin = args[3], mode = args[4];
if (mode > 3)
shutdown("Invalid spi mode");
struct spi_software *spi = oid_alloc(oid, command_config_software_spi
, sizeof(*spi));
spi->sclk = gpio_out_setup(sclk_pin, 0);
spi->mosi = gpio_out_setup(mosi_pin, 0);
spi->miso = gpio_in_setup(miso_pin, 1);
}
DECL_COMMAND(command_config_software_spi,
"config_software_spi oid=%c sclk_pin=%u mosi_pin=%u miso_pin=%u"
" mode=%u rate=%u");
struct spi_software *
spi_software_oid_lookup(uint8_t oid)
{
return oid_lookup(oid, command_config_software_spi);
}
void
spi_software_prepare(struct spi_software *ss)
{
gpio_out_write(ss->sclk, ss->mode < 2 ? 0 : 1);
}
void
spi_software_transfer(struct spi_software *ss, uint8_t receive_data
, uint8_t len, uint8_t *data)
{
while (len--) {
uint8_t outbuf = *data;
uint8_t inbuf = 0;
for (uint_fast8_t i = 0; i < 8; i++) {
if (ss->mode & 0x01) {
// MODE 1 & 3
gpio_out_toggle(ss->sclk);
gpio_out_write(ss->mosi, outbuf & 0x80);
outbuf <<= 1;
gpio_out_toggle(ss->sclk);
inbuf <<= 1;
inbuf |= gpio_in_read(ss->miso);
} else {
// MODE 0 & 2
gpio_out_write(ss->mosi, outbuf & 0x80);
outbuf <<= 1;
gpio_out_toggle(ss->sclk);
inbuf <<= 1;
inbuf |= gpio_in_read(ss->miso);
gpio_out_toggle(ss->sclk);
}
}
if (receive_data)
*data = inbuf;
data++;
}
}

11
src/spi_software.h Normal file
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@ -0,0 +1,11 @@
#ifndef __SPI_SOFTWARE_H
#define __SPI_SOFTWARE_H
#include <stdint.h> // uint8_t
struct spi_software *spi_software_oid_lookup(uint8_t oid);
void spi_software_prepare(struct spi_software *ss);
void spi_software_transfer(struct spi_software *ss, uint8_t receive_data
, uint8_t len, uint8_t *data);
#endif // spi_software.h

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@ -5,14 +5,19 @@
// This file may be distributed under the terms of the GNU GPLv3 license.
#include <string.h> // memcpy
#include "autoconf.h" // CONFIG_HAVE_GPIO_BITBANGING
#include "board/gpio.h" // gpio_out_write
#include "basecmd.h" // oid_alloc
#include "command.h" // DECL_COMMAND
#include "sched.h" // DECL_SHUTDOWN
#include "spi_software.h" // spi_software_setup
#include "spicmds.h" // spidev_transfer
struct spidev_s {
struct spi_config spi_config;
union {
struct spi_config spi_config;
struct spi_software *spi_software;
};
struct gpio_out pin;
uint8_t flags;
uint8_t shutdown_msg_len;
@ -20,7 +25,7 @@ struct spidev_s {
};
enum {
SF_HAVE_PIN = 1,
SF_HAVE_PIN = 1, SF_SOFTWARE = 2,
};
void
@ -58,6 +63,26 @@ DECL_COMMAND(command_config_spi_without_cs,
"config_spi_without_cs oid=%c bus=%u mode=%u rate=%u"
" shutdown_msg=%*s");
void
command_config_spi_from_software(uint32_t *args)
{
uint8_t shutdown_msg_len = args[3];
struct spi_software *sspi = spi_software_oid_lookup(args[1]);
struct spidev_s *spi = oid_alloc(args[0], command_config_spi
, sizeof(*spi) + shutdown_msg_len);
spi->pin = gpio_out_setup(args[2], 1);
spi->flags = SF_HAVE_PIN | SF_SOFTWARE;
spi->spi_software = sspi;
spi->shutdown_msg_len = shutdown_msg_len;
uint8_t *shutdown_msg = (void*)(size_t)args[4];
memcpy(spi->shutdown_msg, shutdown_msg, shutdown_msg_len);
}
#if CONFIG_HAVE_GPIO_BITBANGING
DECL_COMMAND(command_config_spi_from_software,
"config_spi_from_software oid=%c sw_oid=%u pin=%u"
" shutdown_msg=%*s");
#endif
struct spidev_s *
spidev_oid_lookup(uint8_t oid)
{
@ -68,12 +93,18 @@ void
spidev_transfer(struct spidev_s *spi, uint8_t receive_data
, uint8_t data_len, uint8_t *data)
{
spi_prepare(spi->spi_config);
if (CONFIG_HAVE_GPIO_BITBANGING && spi->flags & SF_SOFTWARE)
spi_software_prepare(spi->spi_software);
else
spi_prepare(spi->spi_config);
if (spi->flags & SF_HAVE_PIN)
gpio_out_write(spi->pin, 0);
spi_transfer(spi->spi_config, receive_data, data_len, data);
if (CONFIG_HAVE_GPIO_BITBANGING && spi->flags & SF_SOFTWARE)
spi_software_transfer(spi->spi_software, receive_data, data_len, data);
else
spi_transfer(spi->spi_config, receive_data, data_len, data);
if (spi->flags & SF_HAVE_PIN)
gpio_out_write(spi->pin, 1);