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i2c-ch341-usb.c
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/*
* Driver for the CH341 USB to I2C and GPIO adapter
*
* Copyright (c) 2017 Gunar Schorcht (gunar@schorcht.net)
*
* Derived from
*
* i2c-ch341-usb.c Copyright (c) 2016 Tse Lun Bien
* i2c-ch341.c Copyright (c) 2014 Marco Gittler
* i2c-tiny-usb.c Copyright (c) 2006-2007 Till Harbaum (Till@Harbaum.org)
*
* and extended by GPIO and interrupt handling capabilities.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2.
*/
// uncomment following line to activate kernel debug handling
// #define DEBUG
#define DEBUG_PRINTK
#ifdef DEBUG_PRINTK
#define PRINTK(fmt,...) printk("%s: "fmt"\n", __func__, ##__VA_ARGS__)
#else
#define PRINTK(fmt,...)
#endif
#define CH341_IF_ADDR (&(ch341_dev->usb_if->dev))
#define DEV_ERR(d,f,...) dev_err (d,"%s: "f"\n", __FUNCTION__, ##__VA_ARGS__)
#define DEV_DBG(d,f,...) dev_dbg (d,"%s: "f"\n", __FUNCTION__, ##__VA_ARGS__)
#define DEV_INFO(d,f,...) dev_info(d,"%s: "f"\n", __FUNCTION__, ##__VA_ARGS__)
// check for condition and return with or without err code if it fails
#define CHECK_PARAM_RET(cond,err) if (!(cond)) return err;
#define CHECK_PARAM(cond) if (!(cond)) return;
#include <linux/version.h>
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,4,0)
#error The driver requires at least kernel version 3.4
#else
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/kthread.h>
/**
* ATTENTION:
*
* CH341_POLL_PERIOD_MS in milliseconds defines the rate at which GPIOs are
* read from CH341 via USB and thus the maximum rate at which changes on
* interrupt driven input ports can be recognized at all.
*
* This value must be at least 10 ms, but should be 20 ms or more (if
* possible) dependent on the performance of your system. Please check your
* syslog for messages like "GPIO poll period is too short by at least %n
* msecs". This message is thrown if the defined CH341_POLL_PERIOD_MS is
* shorter than the time required for one reading of the GPIOs.
*/
#define CH341_POLL_PERIOD_MS 10 // see above
#define CH341_GPIO_NUM_PINS 8 // Number of GPIO pins, DO NOT CHANGE
#define CH341_USB_MAX_BULK_SIZE 32 // CH341A wMaxPacketSize for ep_02 and ep_82
#define CH341_USB_MAX_INTR_SIZE 8 // CH341A wMaxPacketSize for ep_81
#define CH341_I2C_LOW_SPEED 0 // low speed - 20kHz
#define CH341_I2C_STANDARD_SPEED 1 // standard speed - 100kHz
#define CH341_I2C_FAST_SPEED 2 // fast speed - 400kHz
#define CH341_I2C_HIGH_SPEED 3 // high speed - 750kHz
#define CH341_CMD_I2C_STREAM 0xAA // I2C stream command
#define CH341_CMD_UIO_STREAM 0xAB // UIO stream command
#define CH341_CMD_I2C_STM_STA 0x74 // I2C set start condition
#define CH341_CMD_I2C_STM_STO 0x75 // I2C set stop condition
#define CH341_CMD_I2C_STM_OUT 0x80 // I2C output data
#define CH341_CMD_I2C_STM_IN 0xC0 // I2C input data
#define CH341_CMD_I2C_STM_SET 0x60 // I2C set configuration
#define CH341_CMD_I2C_STM_END 0x00 // I2C end command
#define CH341_CMD_UIO_STM_IN 0x00 // UIO interface IN command (D0~D7)
#define CH341_CMD_UIO_STM_OUT 0x80 // UIO interface OUT command (D0~D5)
#define CH341_CMD_UIO_STM_DIR 0x40 // UIO interface DIR command (D0~D5)
#define CH341_CMD_UIO_STM_END 0x20 // UIO interface END command
#define CH341_CMD_UIO_STM_US 0xc0 // UIO interface US command
#define CH341_PIN_MODE_OUT 0
#define CH341_PIN_MODE_IN 1
#define CH341_OK 0
/**
*
* Change the default values in *ch341_board_config* for your configuraton
*
* Configurable are:
*
* - Pin 15 (D0/CS0 ) as input/output (CH341_PIN_MODE_IN / CH341_PIN_MODE_OUT)
* - Pin 16 (D1/CS1 ) as input/output (CH341_PIN_MODE_IN / CH341_PIN_MODE_OUT)
* - Pin 17 (D2/CS2 ) as input/output (CH341_PIN_MODE_IN / CH341_PIN_MODE_OUT)
* - Pin 18 (D3/CS2 ) as input/output (CH341_PIN_MODE_IN / CH341_PIN_MODE_OUT)
* - Pin 19 (D4/DOUT2) as input/output (CH341_PIN_MODE_IN / CH341_PIN_MODE_OUT)
* - Pin 20 (D5/DOUT ) as input/output (CH341_PIN_MODE_IN / CH341_PIN_MODE_OUT)
* - Pin 21 (D6/DIN2 ) as input (CH341_PIN_MODE_IN)
* - Pin 22 (D7/DIN ) as input (CH341_PIN_MODE_IN)
*/
struct ch341_pin_config {
uint8_t pin; // pin number of CH341 chip
uint8_t mode; // GPIO mode
char* name; // GPIO name
bool hwirq; // connected to hardware interrupt (only one pin can have true)
};
struct ch341_pin_config ch341_board_config[CH341_GPIO_NUM_PINS] =
{
// pin GPIO mode GPIO name hwirq
{ 15, CH341_PIN_MODE_OUT , "gpio0" , 0 }, // used as output
{ 16, CH341_PIN_MODE_OUT , "gpio1" , 0 }, // used as output
{ 17, CH341_PIN_MODE_OUT , "gpio2" , 0 }, // used as output
{ 18, CH341_PIN_MODE_OUT , "gpio3" , 0 }, // used as output
{ 19, CH341_PIN_MODE_IN , "gpio4" , 1 }, // used as input with hardware IRQ
{ 20, CH341_PIN_MODE_IN , "gpio5" , 0 }, // used as input
{ 21, CH341_PIN_MODE_IN , "gpio6" , 0 }, // used as input
{ 22, CH341_PIN_MODE_IN , "gpio7" , 0 } // used as input
};
// device specific structure
struct ch341_device
{
// USB device description
struct usb_device* usb_dev; // usb device
struct usb_interface* usb_if; // usb interface
struct usb_endpoint_descriptor *ep_in; // usb endpoint bulk in
struct usb_endpoint_descriptor *ep_out; // usb endpoint bulk out
struct usb_endpoint_descriptor *ep_intr; // usb endpoint interrupt in
uint8_t in_buf [CH341_USB_MAX_BULK_SIZE]; // usb input buffer
uint8_t out_buf [CH341_USB_MAX_BULK_SIZE]; // usb outpu buffer
uint8_t intr_buf[CH341_USB_MAX_INTR_SIZE]; // usb interrupt buffer
struct urb* intr_urb;
// I2C device description
struct i2c_adapter i2c_dev; // i2c related things
// GPIO device description
struct gpio_chip gpio; // chip descriptor for GPIOs
uint8_t gpio_num; // number of pins used as GPIOs
uint8_t gpio_mask; // configuratoin mask defines IN/OUT pins
uint8_t gpio_io_data; // current value of CH341 I/O register
struct task_struct * gpio_thread; // GPIO poll thread
struct ch341_pin_config* gpio_pins [CH341_GPIO_NUM_PINS]; // pin configurations (gpio_num elements)
uint8_t gpio_bits [CH341_GPIO_NUM_PINS]; // bit of I/O data byte (gpio_num elements)
uint8_t gpio_values [CH341_GPIO_NUM_PINS]; // current values (gpio_num elements)
char* gpio_names [CH341_GPIO_NUM_PINS]; // pin names (gpio_num elements)
int gpio_irq_map[CH341_GPIO_NUM_PINS]; // GPIO to IRQ map (gpio_num elements)
// IRQ device description
struct irq_chip irq; // chip descriptor for IRQs
uint8_t irq_num; // number of pins with IRQs
int irq_base; // base IRQ allocated
struct irq_desc* irq_descs [CH341_GPIO_NUM_PINS]; // IRQ descriptors used (irq_num elements)
int irq_types [CH341_GPIO_NUM_PINS]; // IRQ types (irq_num elements)
bool irq_enabled [CH341_GPIO_NUM_PINS]; // IRQ enabled flag (irq_num elements)
int irq_gpio_map [CH341_GPIO_NUM_PINS]; // IRQ to GPIO pin map (irq_num elements)
int irq_hw; // IRQ for GPIO with hardware IRQ (default -1)
};
// ----- variables configurable during runtime ---------------------------
static uint speed = CH341_I2C_STANDARD_SPEED; // module parameter speed, default standard speed
static uint speed_last = CH341_I2C_FAST_SPEED + 1; // last used speed, default invalid
static uint poll_period = CH341_POLL_PERIOD_MS; // module parameter poll period
// ----- function prototypes ---------------------------------------------
static int ch341_usb_transfer (struct ch341_device *dev, int out_len, int in_len);
// ----- board configuration layer begin ---------------------------------
static int ch341_cfg_probe (struct ch341_device* ch341_dev)
{
struct ch341_pin_config* cfg;
int i;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
ch341_dev->gpio_mask = 0x3f; // default
ch341_dev->gpio_num = 0;
ch341_dev->gpio_thread = 0;
ch341_dev->irq_num = 0;
ch341_dev->irq_base = 0;
ch341_dev->irq_hw = -1;
for (i = 0; i < CH341_GPIO_NUM_PINS; i++)
{
cfg = ch341_board_config + i;
if (cfg->pin == 0)
continue;
// --- check correct pin configuration ------------
// is pin configurable at all
if (cfg->pin < 15 || cfg->pin > 22)
{
DEV_ERR(CH341_IF_ADDR, "pin %d: is not configurable", cfg->pin);
return -EINVAL;
}
// is pin configured correctly as input in case of pin 21 and 22
if ((cfg->pin == 21 || cfg->pin == 22) && cfg->mode != CH341_PIN_MODE_IN)
{
DEV_ERR(CH341_IF_ADDR, "pin %d: must be an input", cfg->pin);
return -EINVAL;
}
// --- read in pin configuration
// if pin is not configured as CS signal, set GPIO configuration
ch341_dev->gpio_names [ch341_dev->gpio_num] = cfg->name;
ch341_dev->gpio_pins [ch341_dev->gpio_num] = cfg;
ch341_dev->gpio_irq_map[ch341_dev->gpio_num] = -1; // no valid IRQ
// map CH341 pin to bit D0...D7 in the CH341 I/O data byte
ch341_dev->gpio_bits[ch341_dev->gpio_num] = (1 << (cfg->pin - 15));
// GPIO pins can generate IRQs when set to input mode
ch341_dev->gpio_irq_map[ch341_dev->gpio_num] = ch341_dev->irq_num;
ch341_dev->irq_gpio_map[ch341_dev->irq_num] = ch341_dev->gpio_num;
if (cfg->hwirq)
{
if (ch341_dev->irq_hw != -1)
{
DEV_ERR(CH341_IF_ADDR,
"pin %d: only one GPIO can be connected to the hardware IRQ",
cfg->pin);
return -EINVAL;
}
ch341_dev->irq_hw = ch341_dev->irq_num;
}
if (cfg->mode == CH341_PIN_MODE_IN)
// if pin is INPUT, it has to be masked out in GPIO direction mask
ch341_dev->gpio_mask &= ~ch341_dev->gpio_bits[ch341_dev->gpio_num];
DEV_INFO (CH341_IF_ADDR, "%s %s gpio=%d irq=%d %s",
cfg->mode == CH341_PIN_MODE_IN ? "input " : "output",
cfg->name, ch341_dev->gpio_num, ch341_dev->irq_num,
cfg->hwirq ? "(hwirq)" : "");
ch341_dev->irq_num++;
ch341_dev->gpio_num++;
}
return CH341_OK;
}
static void ch341_cfg_remove (struct ch341_device* ch341_dev)
{
CHECK_PARAM (ch341_dev);
return;
}
// ----- board configuration layer end -----------------------------------
// ----- i2c layer begin -------------------------------------------------
static struct mutex ch341_lock;
static int ch341_i2c_set_speed (struct ch341_device *ch341_dev)
{
static char* ch341_i2c_speed_desc[] = { "20 kbps", "100 kbps", "400 kbps", "750 kbps" };
int result;
CHECK_PARAM_RET (speed != speed_last, CH341_OK)
if (speed < CH341_I2C_LOW_SPEED || speed > CH341_I2C_HIGH_SPEED)
{
DEV_ERR (CH341_IF_ADDR, "parameter speed can only have values from 0 to 3");
speed = speed_last;
return -EINVAL;
}
DEV_INFO (CH341_IF_ADDR, "Change i2c bus speed to %s", ch341_i2c_speed_desc[speed]);
mutex_lock (&ch341_lock);
ch341_dev->out_buf[0] = CH341_CMD_I2C_STREAM;
ch341_dev->out_buf[1] = CH341_CMD_I2C_STM_SET | speed;
ch341_dev->out_buf[2] = CH341_CMD_I2C_STM_END;
result = ch341_usb_transfer (ch341_dev, 3, 0);
mutex_unlock (&ch341_lock);
if (result < 0)
{
DEV_ERR (CH341_IF_ADDR, "failure setting speed %d\n", result);
return result;
}
speed_last = speed;
return result;
}
static int ch341_i2c_read_inputs (struct ch341_device* ch341_dev)
{
int result;
if ((result = ch341_i2c_set_speed (ch341_dev)) < 0)
return result;
mutex_lock (&ch341_lock);
ch341_dev->out_buf[0] = CH341_CMD_UIO_STREAM;
ch341_dev->out_buf[1] = CH341_CMD_UIO_STM_DIR | ch341_dev->gpio_mask;
ch341_dev->out_buf[2] = CH341_CMD_UIO_STM_IN;
ch341_dev->out_buf[3] = CH341_CMD_UIO_STM_END;
result = ch341_usb_transfer(ch341_dev, 4, 1);
ch341_dev->gpio_io_data &= ch341_dev->gpio_mask;
ch341_dev->gpio_io_data |= ch341_dev->in_buf[0] & ~ch341_dev->gpio_mask;
mutex_unlock (&ch341_lock);
return (result < 0) ? result : CH341_OK;
}
static int ch341_i2c_write_outputs (struct ch341_device* ch341_dev)
{
int result;
if ((result = ch341_i2c_set_speed (ch341_dev)) < 0)
return result;
mutex_lock (&ch341_lock);
ch341_dev->out_buf[0] = CH341_CMD_UIO_STREAM;
ch341_dev->out_buf[1] = CH341_CMD_UIO_STM_DIR | ch341_dev->gpio_mask;
ch341_dev->out_buf[2] = CH341_CMD_UIO_STM_OUT | (ch341_dev->gpio_io_data & ch341_dev->gpio_mask);
ch341_dev->out_buf[3] = CH341_CMD_UIO_STM_END;
// DEV_DBG(CH341_IF_ADDR, "%02x", ch341_dev->out_buf[2]);
result = ch341_usb_transfer(ch341_dev, 4, 0);
mutex_unlock (&ch341_lock);
return (result < 0) ? result : CH341_OK;
}
static int ch341_i2c_transfer (struct i2c_adapter *adpt, struct i2c_msg *msgs, int num)
{
struct ch341_device* ch341_dev;
int result;
int i, j, k;
uint8_t* ob;
uint8_t* ib;
CHECK_PARAM_RET (adpt, EIO);
CHECK_PARAM_RET (msgs, EIO);
CHECK_PARAM_RET (num > 0, EIO);
ch341_dev = (struct ch341_device *)adpt->algo_data;
CHECK_PARAM_RET (ch341_dev, EIO);
mutex_lock (&ch341_lock);
ob = ch341_dev->out_buf;
ib = ch341_dev->in_buf;
for (i = 0; i < num; i++)
{
// size larger than endpoint max transfer size
if ((msgs[i].len + (i == num-1 ? 6 : 5) > 32))
{
DEV_ERR (CH341_IF_ADDR, "size of data is too large for existing USB endpoints");
result = -EIO;
break;
}
if (msgs[i].flags & I2C_M_TEN)
{
DEV_ERR (CH341_IF_ADDR, "10 bit i2c addresses not supported");
result = -EINVAL;
break;
}
k = 0;
if (msgs[i].flags & I2C_M_RD) // i2c read operation
{
ob[k++] = CH341_CMD_I2C_STREAM;
ob[k++] = CH341_CMD_I2C_STM_STA; // START condition
ob[k++] = CH341_CMD_I2C_STM_OUT | 0x1; // write len (only address byte)
ob[k++] = (msgs[i].addr << 1) | 0x1; // address byte with read flag
if (msgs[i].len)
{
for (j = 0; j < msgs[i].len-1; j++)
ob[k++] = CH341_CMD_I2C_STM_IN | 1;
ob[k++] = CH341_CMD_I2C_STM_IN;
}
// if the message is the last one, add STOP condition
if (i == num-1)
ob[k++] = CH341_CMD_I2C_STM_STO;
ob[k++] = CH341_CMD_I2C_STM_END;
// wirte address byte and read data
result = ch341_usb_transfer(ch341_dev, k, msgs[i].len);
// if data were read
if (result > 0)
{
if (msgs[i].flags & I2C_M_RECV_LEN)
{
msgs[i].buf[0] = result; // length byte
memcpy(msgs[i].buf+1, ib, msgs[i].len);
}
else
{
memcpy(msgs[i].buf, ib, msgs[i].len);
}
}
}
else // i2c write operation
{
ob[k++] = CH341_CMD_I2C_STREAM;
ob[k++] = CH341_CMD_I2C_STM_STA; // START condition
ob[k++] = CH341_CMD_I2C_STM_OUT | (msgs[i].len + 1);
ob[k++] = msgs[i].addr << 1; // address byte
memcpy(&ob[k], msgs[i].buf, msgs[i].len);
k = k + msgs[i].len;
// if the message is the last one, add STOP condition
if (i == num-1)
ob[k++] = CH341_CMD_I2C_STM_STO;
ob[k++] = CH341_CMD_I2C_STM_END;
// write address byte and data
result = ch341_usb_transfer (ch341_dev, k, 0);
}
if (result < 0)
break;
}
mutex_unlock (&ch341_lock);
if (result < 0)
return result;
return num;
}
static u32 ch341_i2c_func (struct i2c_adapter *dev)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm ch341_i2c_algorithm =
{
.master_xfer = ch341_i2c_transfer,
.functionality = ch341_i2c_func,
};
static int ch341_i2c_probe (struct ch341_device* ch341_dev)
{
int result;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
DEV_DBG (CH341_IF_ADDR, "start");
// setup i2c adapter description
ch341_dev->i2c_dev.owner = THIS_MODULE;
ch341_dev->i2c_dev.class = 0; // I2C_CLASS_HWMON;
ch341_dev->i2c_dev.algo = &ch341_i2c_algorithm;
ch341_dev->i2c_dev.algo_data = ch341_dev;
snprintf(ch341_dev->i2c_dev.name, sizeof(ch341_dev->i2c_dev.name),
"i2c-ch341-usb at bus %03d device %03d",
ch341_dev->usb_dev->bus->busnum, ch341_dev->usb_dev->devnum);
ch341_dev->i2c_dev.dev.parent = &ch341_dev->usb_if->dev;
// finally attach to i2c layer
if ((result = i2c_add_adapter(&ch341_dev->i2c_dev)) < 0)
return result;
DEV_INFO (CH341_IF_ADDR, "created i2c device /dev/i2c-%d", ch341_dev->i2c_dev.nr);
mutex_init (&ch341_lock);
// set ch341 i2c speed
speed_last = CH341_I2C_FAST_SPEED+1;
if ((result = ch341_i2c_set_speed (ch341_dev)) < 0)
return result;
DEV_DBG (CH341_IF_ADDR, "done");
return CH341_OK;
}
static void ch341_i2c_remove (struct ch341_device* ch341_dev)
{
CHECK_PARAM (ch341_dev);
if (ch341_dev->i2c_dev.nr)
i2c_del_adapter (&ch341_dev->i2c_dev);
return;
}
// ----- i2c layer end ---------------------------------------------------
// ----- irq layer begin -------------------------------------------------
void ch341_irq_enable_disable (struct irq_data *data, bool enable)
{
struct ch341_device *ch341_dev;
int irq;
CHECK_PARAM (data && (ch341_dev = irq_data_get_irq_chip_data(data)));
// calculate local IRQ
irq = data->irq - ch341_dev->irq_base;
// valid IRQ is in range 0 ... ch341_dev->irq_num-1, invalid IRQ is -1
if (irq < 0 || irq >= ch341_dev->irq_num) return;
// enable local IRQ
ch341_dev->irq_enabled[irq] = enable;
DEV_INFO (CH341_IF_ADDR, "irq=%d enabled=%d",
data->irq, ch341_dev->irq_enabled[irq] ? 1 : 0);
}
void ch341_irq_enable (struct irq_data *data)
{
ch341_irq_enable_disable (data, true);
}
void ch341_irq_disable (struct irq_data *data)
{
ch341_irq_enable_disable (data, false);
}
int ch341_irq_set_type (struct irq_data *data, unsigned int type)
{
struct ch341_device *ch341_dev;
int irq;
CHECK_PARAM_RET (data && (ch341_dev = irq_data_get_irq_chip_data(data)), -EINVAL);
// calculate local IRQ
irq = data->irq - ch341_dev->irq_base;
// valid IRQ is in range 0 ... ch341_dev->irq_num-1, invalid IRQ is -1
if (irq < 0 || irq >= ch341_dev->irq_num) return -EINVAL;
ch341_dev->irq_types[irq] = type;
DEV_INFO (CH341_IF_ADDR, "irq=%d flow_type=%d", data->irq, type);
return CH341_OK;
}
static int ch341_irq_check (struct ch341_device* ch341_dev, uint8_t irq,
uint8_t old, uint8_t new, bool hardware)
{
int type;
CHECK_PARAM_RET (old != new, CH341_OK)
CHECK_PARAM_RET (ch341_dev, -EINVAL);
CHECK_PARAM_RET (irq < ch341_dev->irq_num, -EINVAL);
// valid IRQ is in range 0 ... ch341_dev->irq_num-1, invalid IRQ is -1
if (irq < 0 || irq >= ch341_dev->irq_num) return -EINVAL;
// if IRQ is disabled, just return with success
if (!ch341_dev->irq_enabled[irq]) return CH341_OK;
type = ch341_dev->irq_types[irq];
// for software IRQs dont check if IRQ is the hardware IRQ for rising edges
if (!hardware && irq == ch341_dev->irq_hw && new > old)
return CH341_OK;
if ((type & IRQ_TYPE_EDGE_FALLING && old > new) ||
(type & IRQ_TYPE_EDGE_RISING && new > old))
{
// DEV_DBG (CH341_IF_ADDR, "%s irq=%d %d %s",
// hardware ? "hardware" : "software",
// irq, type, (old > new) ? "falling" : "rising");
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,3,0)
handle_simple_irq (ch341_dev->irq_descs[irq]);
#else
handle_simple_irq (ch341_dev->irq_base+irq, ch341_dev->irq_descs[irq]);
#endif
}
return CH341_OK;
}
static int ch341_irq_probe (struct ch341_device* ch341_dev)
{
int i;
int result;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
DEV_DBG (CH341_IF_ADDR, "start");
ch341_dev->irq.name = "ch341";
ch341_dev->irq.irq_enable = ch341_irq_enable;
ch341_dev->irq.irq_disable = ch341_irq_disable;
ch341_dev->irq.irq_set_type = ch341_irq_set_type;
if (!ch341_dev->irq_num) return CH341_OK;
if ((result = irq_alloc_descs(-1, 0, ch341_dev->irq_num, 0)) < 0)
{
DEV_ERR (CH341_IF_ADDR, "failed to allocate IRQ descriptors");
return result;
}
ch341_dev->irq_base = result;
DEV_DBG (CH341_IF_ADDR, "irq_base=%d", ch341_dev->irq_base);
for (i = 0; i < ch341_dev->irq_num; i++)
{
ch341_dev->irq_descs[i] = irq_data_to_desc( irq_get_irq_data(ch341_dev->irq_base + i) );
ch341_dev->irq_enabled[i] = false;
irq_set_chip (ch341_dev->irq_base + i, &ch341_dev->irq);
irq_set_chip_data (ch341_dev->irq_base + i, ch341_dev);
irq_clear_status_flags(ch341_dev->irq_base + i, IRQ_NOREQUEST | IRQ_NOPROBE);
}
DEV_DBG (CH341_IF_ADDR, "done");
return CH341_OK;
}
static void ch341_irq_remove (struct ch341_device* ch341_dev)
{
CHECK_PARAM (ch341_dev);
if (ch341_dev->irq_base)
irq_free_descs (ch341_dev->irq_base, ch341_dev->irq_num);
return;
}
// ----- irq layer end ---------------------------------------------------
// ----- gpio layer begin ------------------------------------------------
void ch341_gpio_read_inputs (struct ch341_device* ch341_dev)
{
uint8_t old_io_data;
uint8_t old_value;
uint8_t new_value;
uint8_t gpio;
int i;
CHECK_PARAM (ch341_dev);
// DEV_DBG (CH341_IF_ADDR, "start");
// save old value
old_io_data = ch341_dev->gpio_io_data;
// read current values
ch341_i2c_read_inputs (ch341_dev);
for (i = 0; i < ch341_dev->irq_num; i++)
{
// determine local GPIO for each IRQ
gpio = ch341_dev->irq_gpio_map[i];
// determin old an new value of the bit
old_value = (old_io_data & ch341_dev->gpio_bits[gpio]) ? 1 : 0;
new_value = (ch341_dev->gpio_io_data & ch341_dev->gpio_bits[gpio]) ? 1 : 0;
// check for interrupt
ch341_irq_check (ch341_dev, i, old_value, new_value, false);
}
// DEV_DBG (CH341_IF_ADDR, "done");
}
// #define CH341_POLL_WITH_SLEEP
static int ch341_gpio_poll_function (void* argument)
{
struct ch341_device* ch341_dev = (struct ch341_device*)argument;
unsigned int next_poll_ms = jiffies_to_msecs(jiffies);
unsigned int jiffies_ms;
int drift_ms = 0;
int corr_ms = 0;
int sleep_ms = 0;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
DEV_DBG (CH341_IF_ADDR, "start");
while (!kthread_should_stop())
{
// current time in ms
jiffies_ms = jiffies_to_msecs(jiffies);
drift_ms = jiffies_ms - next_poll_ms;
if (poll_period == 0)
{
poll_period = CH341_POLL_PERIOD_MS;
DEV_ERR (CH341_IF_ADDR,
"Poll period 0 ms is invalid, set back to the default of %d ms",
CH341_POLL_PERIOD_MS);
}
if (drift_ms < 0)
{
// period was to short, increase corr_ms by 1 ms
// DEV_DBG (CH341_IF_ADDR, "polling GPIO is %u ms too early", -drift_ms);
corr_ms = (corr_ms > 0) ? corr_ms - 1 : 0;
}
else if (drift_ms > 0 && drift_ms < poll_period)
{
// period was to long, decrease corr_ms by 1 ms
// DEV_DBG (CH341_IF_ADDR, "polling GPIO is %u ms too late", drift_ms);
corr_ms = (corr_ms < poll_period) ? corr_ms + 1 : 0;
}
next_poll_ms = jiffies_ms + poll_period;
// DEV_DBG (CH341_IF_ADDR, "read CH341 GPIOs");
ch341_gpio_read_inputs (ch341_dev);
jiffies_ms = jiffies_to_msecs(jiffies);
// if GPIO read took longer than poll period, do not sleep
if (jiffies_ms > next_poll_ms)
{
DEV_ERR (CH341_IF_ADDR,
"GPIO poll period is too short by at least %u msecs",
jiffies_ms - next_poll_ms);
}
else
{
sleep_ms = next_poll_ms - jiffies_ms - corr_ms;
#ifdef CH341_POLL_WITH_SLEEP
msleep ((sleep_ms <= 0) ? 1 : sleep_ms);
#else
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(msecs_to_jiffies((sleep_ms <= 0) ? 1 : sleep_ms));
#endif
}
}
#ifndef CH341_POLL_WITH_SLEEP
__set_current_state(TASK_RUNNING);
#endif
DEV_DBG (CH341_IF_ADDR, "stop");
return 0;
}
int ch341_gpio_get (struct gpio_chip *chip, unsigned offset)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)
struct ch341_device* ch341_dev = (struct ch341_device*)gpiochip_get_data(chip);
#else
struct ch341_device* ch341_dev = container_of(chip, struct ch341_device, gpio);
#endif
int value;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
CHECK_PARAM_RET (offset < ch341_dev->gpio_num, -EINVAL);
value = (ch341_dev->gpio_io_data & ch341_dev->gpio_bits[offset]) ? 1 : 0;
// DEV_DBG (CH341_IF_ADDR, "offset=%u value=%d io_data=%02x",
// offset, value, ch341_dev->gpio_io_data);
return value;
}
// FIXME: not tested at the moment (will be introduced with kernel 4.15.0)
int ch341_gpio_get_multiple (struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)
struct ch341_device* ch341_dev = (struct ch341_device*)gpiochip_get_data(chip);
#else
struct ch341_device* ch341_dev = container_of(chip, struct ch341_device, gpio);
#endif
int i;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
CHECK_PARAM_RET (mask, -EINVAL);
CHECK_PARAM_RET (bits, -EINVAL);
for (i = 0; i < ch341_dev->gpio_num; i++)
if (*mask & (1 << i))
{
*bits &= ~(1 << i);
*bits |= (((ch341_dev->gpio_io_data & ch341_dev->gpio_bits[i]) ? 1 : 0) << i);
}
// DEV_DBG (CH341_IF_ADDR, "mask=%08lx bit=%08lx io_data=%02x",
// *mask, *bits, ch341_dev->gpio_io_data);
return CH341_OK;
}
void ch341_gpio_set (struct gpio_chip *chip, unsigned offset, int value)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)
struct ch341_device* ch341_dev = (struct ch341_device*)gpiochip_get_data(chip);
#else
struct ch341_device* ch341_dev = container_of(chip, struct ch341_device, gpio);
#endif
CHECK_PARAM (ch341_dev);
CHECK_PARAM (offset < ch341_dev->gpio_num);
if (value)
ch341_dev->gpio_io_data |= ch341_dev->gpio_bits[offset];
else
ch341_dev->gpio_io_data &= ~ch341_dev->gpio_bits[offset];
// DEV_DBG (CH341_IF_ADDR, "offset=%u value=%d io_data=%02x",
// offset, value, ch341_dev->gpio_io_data);
ch341_i2c_write_outputs (ch341_dev);
}
void ch341_gpio_set_multiple (struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)
struct ch341_device* ch341_dev = (struct ch341_device*)gpiochip_get_data(chip);
#else
struct ch341_device* ch341_dev = container_of(chip, struct ch341_device, gpio);
#endif
int i;
CHECK_PARAM (ch341_dev);
CHECK_PARAM (mask);
CHECK_PARAM (bits);
for (i = 0; i < ch341_dev->gpio_num; i++)
if (*mask & (1 << i) && ch341_dev->gpio_pins[i]->mode == CH341_PIN_MODE_OUT)
{
if (*bits & (1 << i))
ch341_dev->gpio_io_data |= ch341_dev->gpio_bits[i];
else
ch341_dev->gpio_io_data &= ~ch341_dev->gpio_bits[i];
}
// DEV_DBG (CH341_IF_ADDR, "mask=%08lx bit=%08lx io_data=%02x",
// *mask, *bits, ch341_dev->gpio_io_data);
ch341_i2c_write_outputs (ch341_dev);
return;
}
int ch341_gpio_get_direction (struct gpio_chip *chip, unsigned offset)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)
struct ch341_device* ch341_dev = (struct ch341_device*)gpiochip_get_data(chip);
#else
struct ch341_device* ch341_dev = container_of(chip, struct ch341_device, gpio);
#endif
int mode;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
CHECK_PARAM_RET (offset < ch341_dev->gpio_num, -EINVAL);
mode = (ch341_dev->gpio_pins[offset]->mode == CH341_PIN_MODE_IN) ? 1 : 0;
DEV_DBG (CH341_IF_ADDR, "gpio=%d dir=%d", offset, mode);
return mode;
}
int ch341_gpio_set_direction (struct gpio_chip *chip, unsigned offset, bool input)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)
struct ch341_device* ch341_dev = (struct ch341_device*)gpiochip_get_data(chip);
#else
struct ch341_device* ch341_dev = container_of(chip, struct ch341_device, gpio);
#endif
CHECK_PARAM_RET (ch341_dev, -EINVAL);
CHECK_PARAM_RET (offset < ch341_dev->gpio_num, -EINVAL);
// pin configured correctly if it is pin 21
if (ch341_dev->gpio_pins[offset]->pin == 21 && !input)
{
DEV_ERR(CH341_IF_ADDR, "pin 21: must be an input");
return -EINVAL;
}
DEV_INFO (CH341_IF_ADDR, "gpio=%d direction=%s", offset, input ? "input" : "output");
ch341_dev->gpio_pins[offset]->mode = input ? CH341_PIN_MODE_IN : CH341_PIN_MODE_OUT;
// mask in / mask out the according bit in direction mask
if (ch341_dev->gpio_pins[offset]->mode == CH341_PIN_MODE_OUT)
ch341_dev->gpio_mask |= ch341_dev->gpio_bits[offset];
else
ch341_dev->gpio_mask &= ~ch341_dev->gpio_bits[offset];
return CH341_OK;
}
int ch341_gpio_direction_input (struct gpio_chip *chip, unsigned offset)
{
return ch341_gpio_set_direction (chip, offset, true);
}
int ch341_gpio_direction_output (struct gpio_chip *chip, unsigned offset, int value)
{
int result = CH341_OK;
if ((result = ch341_gpio_set_direction (chip, offset, false)) == CH341_OK)
// set initial output value
ch341_gpio_set (chip, offset, value);
return result;
}
int ch341_gpio_to_irq (struct gpio_chip *chip, unsigned offset)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)
struct ch341_device* ch341_dev = (struct ch341_device*)gpiochip_get_data(chip);
#else
struct ch341_device* ch341_dev = container_of(chip, struct ch341_device, gpio);
#endif
int irq;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
CHECK_PARAM_RET (offset < ch341_dev->gpio_num, -EINVAL);
// valid IRQ is in range 0 ... ch341_dev->irq_num, invalid IRQ is -1
irq = ch341_dev->gpio_irq_map[offset];
irq = (irq >= 0 ? ch341_dev->irq_base + irq : 0);
DEV_DBG (CH341_IF_ADDR, "gpio=%d irq=%d", offset, irq);
return irq;
}
static int ch341_gpio_probe (struct ch341_device* ch341_dev)
{
struct gpio_chip *gpio = &ch341_dev->gpio;
int result;
int i, j = 0;
CHECK_PARAM_RET (ch341_dev, -EINVAL);
DEV_DBG (CH341_IF_ADDR, "start");
gpio->label = "ch341";
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,5,0)