埋め込みLinuxドライバのロードに関する問題...
組み込みLinuxドライバ
TIのチップAM 4378の開発ボードでlinuxを実行する.ツールチェーンはgcc-linaro-5.3-2016.02-x 86_64_arm-linux-gnueabihfボードサブコアバージョン4.1.18ホストUbuntu 18.x
QEPドライブを追加するには、次の手順に従います.カーネルフォルダの下にlinux-master/driversの新しいフォルダqepにドライバファイルtieqepを追加します.c
makefileの追加
Kconfigファイルの追加
これによりlinux-master/drivers/qepフォルダの下に3つのファイルlinux-master/drivers/qep/tieqepがある.c linux-master/drivers/qep/makefile linux-master/drivers/qep/Kconfigの3つのファイル2.前のレベルのディレクトリのlinux-master/drivers/makefile追加
linux-master/drivers/Kconfig追加
3.linux-master/Kconfigで追加
4.次にmake menuconfigでカーネル*make zImageコンパイル5にコンパイルすることを選択する.問題は、開発ボードコンソールに入ると、/sys/classでqepという駆動フォルダが表示されません.
すみません、ドライバコードに問題があるのか、makeプロセスに問題があるのか、それともカーネルにコンパイルされたのは位置エラーなのか.
TIのチップAM 4378の開発ボードでlinuxを実行する.ツールチェーンはgcc-linaro-5.3-2016.02-x 86_64_arm-linux-gnueabihfボードサブコアバージョン4.1.18ホストUbuntu 18.x
QEPドライブを追加するには、次の手順に従います.カーネルフォルダの下にlinux-master/driversの新しいフォルダqepにドライバファイルtieqepを追加します.c
/*
* TI eQEP driver for AM33xx devices
* sysfs entries
* - position = absolute - current position; relative - last latched value
* - mode => 0 - absolute; 1 - relative
* - period => sampling period for the hardware
* - enable => 0 - eQEP disabled, 1 - eQEP enabled
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
// Include the PWMSS subsystem headers, because this unit controls
// whether our clock source is enabled, and if eQEP is to be
// enabled, we need to start the clock
#include "../pwm/pwm-tipwmss.h"
// eQEP register offsets from its base IO address
#define QPOSCNT 0x0000
#define QPOSINIT 0x0004
#define QPOSMAX 0x0008
#define QPOSCMP 0x000C
#define QPOSILAT 0x0010
#define QPOSSLAT 0x0014
#define QPOSLAT 0x0018
#define QUTMR 0x001C
#define QUPRD 0x0020
#define QWDTMR 0x0024
#define QWDPRD 0x0026
#define QDECCTL 0x0028
#define QEPCTL 0x002A
#define QCAPCTL 0x002C
#define QPOSCTL 0x002E
#define QEINT 0x0030
#define QFLG 0x0032
#define QCLR 0x0034
#define QFRC 0x0036
#define QEPSTS 0x0038
#define QCTMR 0x003A
#define QCPRD 0x003C
#define QCTMRLAT 0x003E
#define QCPRDLAT 0x0040
#define QREVID 0x005C
// Bits for the QDECTL register
#define QSRC1 (0x0001 << 15)
#define QSRC0 (0x0001 << 14)
#define SOEN (0x0001 << 13)
#define SPSEL (0x0001 << 12)
#define XCR (0x0001 << 11)
#define SWAP (0x0001 << 10)
#define IGATE (0x0001 << 9)
#define QAP (0x0001 << 8)
#define QBP (0x0001 << 7)
#define QIP (0x0001 << 6)
#define QSP (0x0001 << 5)
// Bits for the QEPCTL register
#define FREESOFT1 (0x0001 << 15)
#define FREESOFT0 (0x0001 << 14)
#define PCRM1 (0x0001 << 13)
#define PCRM0 (0x0001 << 12)
#define SEI1 (0x0001 << 11)
#define SEI0 (0x0001 << 10)
#define IEI1 (0x0001 << 9)
#define IEI0 (0x0001 << 8)
#define SWI (0x0001 << 7)
#define SEL (0x0001 << 6)
#define IEL1 (0x0001 << 5)
#define IEL0 (0x0001 << 4)
#define PHEN (0x0001 << 3)
#define QCLM (0x0001 << 2)
#define UTE (0x0001 << 1)
#define WDE (0x0001 << 0)
// Bits for the QEPCTL register
#define QDF (0x0001 << 5)
// Bits for the QCAPCTL register
#define CEN (0x0001 << 15)
#define CCPS2 (0x0001 << 6)
#define CCPS0 (0x0001 << 5)
#define CCPS1 (0x0001 << 4)
#define UPPS3 (0x0001 << 3)
#define UPPS2 (0x0001 << 2)
#define UPPS1 (0x0001 << 1)
#define UPPS0 (0x0001 << 0)
// Bits for the QPOSCTL register
#define PCSHDW (0x0001 << 15)
#define PCLOAD (0x0001 << 14)
#define PCPOL (0x0001 << 13)
#define PCE (0x0001 << 12)
#define PCSPW11 (0x0001 << 11)
#define PCSPW10 (0x0001 << 10)
#define PCSPW9 (0x0001 << 9)
#define PCSPW8 (0x0001 << 8)
#define PCSPW7 (0x0001 << 7)
#define PCSPW6 (0x0001 << 6)
#define PCSPW5 (0x0001 << 5)
#define PCSPW4 (0x0001 << 4)
#define PCSPW3 (0x0001 << 3)
#define PCSPW2 (0x0001 << 2)
#define PCSPW1 (0x0001 << 1)
#define PCSPW0 (0x0001 << 0)
// Bits for the interrupt registers
#define EQEP_INTERRUPT_MASK (0x0FFF)
#define UTOF (0x0001 << 11)
// Bits to control the clock in the PWMSS subsystem
#define PWMSS_EQEPCLK_EN BIT(4)
#define PWMSS_EQEPCLK_STOP_REQ BIT(5)
#define PWMSS_EQEPCLK_EN_ACK BIT(4)
// Modes for the eQEP unit
// Absolute - the position entry represents the current position of the encoder.
// Poll this value and it will be notified every period nanoseconds
// Relative - the position entry represents the last latched position of the encoder
// This value is latched every period nanoseconds and the internal counter
// is subsequenty reset
#define TIEQEP_MODE_ABSOLUTE 0
#define TIEQEP_MODE_RELATIVE 1
// Structure defining the characteristics of the eQEP unit
struct eqep_chip
{
// Platform device for this eQEP unit
struct platform_device *pdev;
// Pointer to the base of the memory of the eQEP unit
void __iomem *mmio_base;
// SYSCLKOUT to the eQEP unit
u32 clk_rate;
// IRQ for the eQEP unit
u16 irq;
// Mode of the eQEP unit
u8 mode;
// work stuct for the notify userspace work
struct work_struct notify_work;
// Backup for driver suspension
u16 prior_qepctl;
u16 prior_qeint;
};
// Notify userspace work
void notify_handler (struct work_struct *work)
{
// Get a reference to the eQEP driver
struct eqep_chip *eqep = container_of(work, struct eqep_chip, notify_work);
// Notify the userspace
sysfs_notify(&eqep->pdev->dev.kobj, NULL, "position");
}
// eQEP Interrupt handler
static irqreturn_t eqep_irq_handler(int irq, void *dev_id)
{
// Get the instance information
struct platform_device *pdev = dev_id;
struct eqep_chip *eqep = platform_get_drvdata(pdev);
// Get the interrupt flags
u16 iflags = readw(eqep->mmio_base + QFLG) & EQEP_INTERRUPT_MASK;
// Check the interrupt source(s)
if(iflags & UTOF)
{
// Handle the unit timer overflow interrupt by notifying any potential pollers
schedule_work(&eqep->notify_work);
}
// Clear interrupt flags (write back triggered flags to the clear register)
writew(iflags, eqep->mmio_base + QCLR);
// Return that the IRQ was handled successfully
return IRQ_HANDLED;
}
// Function to read whether the eQEP unit is enabled or disabled
static ssize_t eqep_get_enabled(struct device *dev, struct device_attribute *attr, char *buf)
{
// Get the instance structure
struct eqep_chip *eqep = dev_get_drvdata(dev);
// Read the qep control register and mask all but the enabled bit
u16 enabled = readw(eqep->mmio_base + QEPCTL) & PHEN;
// Return the target in string format
return sprintf(buf, "%u
", (enabled) ? 1 : 0);
}
// Function to set if the eQEP is enabled
static ssize_t eqep_set_enabled(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
// Get the instance structure
int rc;
u16 val;
u8 enabled;
struct eqep_chip *eqep = dev_get_drvdata(dev);
// Convert the input string to an 8 bit uint
if ((rc = kstrtou8(buf, 0, &enabled)))
return rc;
// Get the existing state of QEPCTL
val = readw(eqep->mmio_base + QEPCTL);
// If we passed a number that is not 0, enable the eQEP
if(enabled)
{
// Enable the eQEP (Set PHEN in QEPCTL)
val = val | PHEN;
} else
{
// Disable the eQEP (Clear PHEN in QEPCTL)
val = val & ~PHEN;
}
// Write flags back to control register
writew(val, eqep->mmio_base + QEPCTL);
// Return buffer length consumed (all)
return count;
}
// Function to read the current position of the eQEP
static ssize_t eqep_get_position(struct device *dev, struct device_attribute *attr, char *buf)
{
// Get the instance structure
struct eqep_chip *eqep = dev_get_drvdata(dev);
// A variable to return the position with
s32 position = 0;
// Check the mode
if(eqep->mode == TIEQEP_MODE_ABSOLUTE)
{
// If we are in absolute mode, we need the current value of the eQEP hardware
position = readl(eqep->mmio_base + QPOSCNT);
} else if(eqep->mode == TIEQEP_MODE_RELATIVE)
{
// If we are in relative mode, we need the last latched value of the eQEP hardware
position = readl(eqep->mmio_base + QPOSLAT);
}
// Return the target in string format
return sprintf(buf, "%d
", position);
}
// Function to set the position of the eQEP hardware
static ssize_t eqep_set_position(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
// Get the instance structure
int rc;
s32 position;
struct eqep_chip *eqep = dev_get_drvdata(dev);
// Convert the input string to an 8 bit uint
if ((rc = kstrtos32(buf, 0, &position)))
return rc;
// If we are in absolute mode, set the position of the encoder, discard relative mode because thats pointless
if(eqep->mode == TIEQEP_MODE_ABSOLUTE)
{
// If we are in absolute mode, we need the current value of the eQEP hardware
writel(position, eqep->mmio_base + QPOSCNT);
}
// Return buffer length consumed (all)
return count;
}
static ssize_t eqep_set_direction(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
return 1;
}
// Function to read the current direction of the eQEP
static ssize_t eqep_get_direction(struct device *dev, struct device_attribute *attr, char *buf)
{
// Get the instance structure
struct eqep_chip *eqep = dev_get_drvdata(dev);
// A variable to return the direction with
s32 direction = 0;
// If we are in relative mode, we need the last latched value of the eQEP hardware
direction = readl(eqep->mmio_base + QEPSTS);
// Return the target in string format
return sprintf(buf, "%d
", direction);
}
// Function to read the period of the unit time event timer
static ssize_t eqep_get_timer_period(struct device *dev, struct device_attribute *attr, char *buf)
{
// Get the instance structure
struct eqep_chip *eqep = dev_get_drvdata(dev);
u64 period = 0;
// Check if the period timer is enabled, if not, return 0
if(!(readw(eqep->mmio_base + QEPCTL) & UTE))
{
return sprintf(buf, "0
");
}
// Convert from counts per interrupt back into period_ns
period = readl(eqep->mmio_base + QUPRD);
period = period * NSEC_PER_SEC;
do_div(period, eqep->clk_rate);
// Otherwise write out the data
return sprintf(buf, "%llu
", period);
}
// Function to set the unit timer period. 0 = off, greater than zero sets the period
static ssize_t eqep_set_timer_period(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
int rc;
u16 tmp;
u64 period;
// Get the instance structure
struct eqep_chip *eqep = dev_get_drvdata(dev);
// Convert the passed string to a 64 bit uint
if((rc = kstrtou64(buf, 0, &period)))
return rc;
// Disable the unit timer before modifying its period register
tmp = readw(eqep->mmio_base + QEPCTL);
tmp = tmp & ~UTE & ~QCLM;
writew(tmp, eqep->mmio_base + QEPCTL);
// Zero the unit timer counter register
writel(0x0, eqep->mmio_base + QUTMR);
// If we want the timer enabled (a period that is non zero has been passed)
if(period)
{
// Otherwise calculate the period
period = period * eqep->clk_rate;
do_div(period, NSEC_PER_SEC);
// Set this period into the unit timer period register
writel(period & 0x00000000FFFFFFFF, eqep->mmio_base + QUPRD);
// Enable the unit timer, and latch QPOSLAT to QPOSCNT on overflow
tmp = readw(eqep->mmio_base + QEPCTL);
tmp = tmp | UTE | QCLM;
writew(tmp, eqep->mmio_base + QEPCTL);
}
// Return consumed buffer count
return count;
}
// Function to read the mode of the eQEP hardware
static ssize_t eqep_get_mode(struct device *dev, struct device_attribute *attr, char *buf)
{
// Get the instance structure
struct eqep_chip *eqep = dev_get_drvdata(dev);
// Return the mode
return sprintf(buf, "%u
", eqep->mode);
}
// Function to set the mode of the eQEP hardware
static ssize_t eqep_set_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
// Get the instance structure
int rc;
u16 val;
u8 tmp_mode;
struct eqep_chip *eqep = dev_get_drvdata(dev);
// Convert the input string to an 8 bit uint
if ((rc = kstrtou8(buf, 0, &tmp_mode)))
return rc;
// Get the existing state of QEPCTL
val = readw(eqep->mmio_base + QEPCTL);
// Check the mode that was passed
if(tmp_mode == TIEQEP_MODE_ABSOLUTE)
{
// In absolute mode, we don't want to reset the intenal hardware based on time,
// so disable the unit timer position reset (Set PCRM[1:0] = 0)
val = val & ~PCRM1 & ~PCRM0;
// Store the mode as absolute
eqep->mode = TIEQEP_MODE_ABSOLUTE;
} else if(tmp_mode == TIEQEP_MODE_RELATIVE)
{
// In relative mode, we want to latch the value of the eQEP hardware on the
// overflow of the unit timer. So enable the unit timer position reset
// (Set PCRM[1:0] = 3)
val = val | PCRM1 | PCRM0;
// Store the mode as relative
eqep->mode = TIEQEP_MODE_RELATIVE;
}
// Write the new value back to the control register
writew(val, eqep->mmio_base + QEPCTL);
// Return buffer length consumed (all)
return count;
}
// Bind read/write functions to sysfs entries
static DEVICE_ATTR(enabled, 0644, eqep_get_enabled, eqep_set_enabled);
static DEVICE_ATTR(position, 0644, eqep_get_position, eqep_set_position);
static DEVICE_ATTR(period, 0644, eqep_get_timer_period, eqep_set_timer_period);
static DEVICE_ATTR(mode, 0644, eqep_get_mode, eqep_set_mode);
static DEVICE_ATTR(direction,0644, eqep_get_direction, eqep_set_direction);
// Array holding all of the sysfs entries
static const struct attribute *eqep_attrs[] = {
&dev_attr_enabled.attr,
&dev_attr_position.attr,
&dev_attr_period.attr,
&dev_attr_mode.attr,
&dev_attr_direction.attr,
NULL,
};
// Driver function group
static const struct attribute_group eqep_device_attr_group = {
.attrs = (struct attribute **) eqep_attrs,
};
// Driver compatibility list
static struct of_device_id eqep_of_match[] =
{
{ .compatible = "ti,am33xx-eqep" },
{ }
};
// Register our compatibilities for device trees
MODULE_DEVICE_TABLE(of, eqep_of_match);
// Create an instance of the eQEP driver
static int eqep_probe(struct platform_device *pdev)
{
struct resource *r;
struct clk *clk;
struct eqep_chip *eqep;
struct pinctrl *pinctrl;
int ret;
u64 period;
u16 status;
// Select any default pins possible provided through the device tree
pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
if (IS_ERR(pinctrl))
{
dev_warn(&pdev->dev, "unable to select pin group
");
}
// Allocate a eqep_driver object
eqep = devm_kzalloc(&pdev->dev, sizeof(struct eqep_chip), GFP_KERNEL);
if (!eqep) {
dev_err(&pdev->dev, "failed to allocate memory
");
return -ENOMEM;
}
// Get a handle to the system clock object
clk = devm_clk_get(&pdev->dev, "fck");
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "failed to get clock
");
return PTR_ERR(clk);
}
// Get the frequency of the system clock
eqep->clk_rate = clk_get_rate(clk);
if (!eqep->clk_rate) {
dev_err(&pdev->dev, "failed to get clock rate
");
return -EINVAL;
}
// Get a resource containing the IRQ for this eQEP controller
r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (unlikely(!r)) {
dev_err(&pdev->dev, "Invalid IRQ resource
");
return -ENODEV;
}
// Store the irq
eqep->irq = r->start;
// Get a resource containing the requested (from DT) memory address and range of eQEP controller
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
dev_err(&pdev->dev, "no memory resource defined
");
return -ENODEV;
}
// Remap the eQEP controller memory into our own memory space
eqep->mmio_base = devm_ioremap_resource(&pdev->dev, r);
if (!eqep->mmio_base)
return -EADDRNOTAVAIL;
// Store the platform device in our eQEP data structure for later usage
eqep->pdev = pdev;
// Subscribe to the eQEP interrupt
if (request_irq(eqep->irq, eqep_irq_handler, IRQF_IRQPOLL, "eqep_interrupt", pdev))
{
dev_err(&pdev->dev, "unable to request irq for eQEP
");
return -ENODEV;
}
// Register controls to sysfs
if (sysfs_create_group(&pdev->dev.kobj, &eqep_device_attr_group))
{
dev_err(&pdev->dev, "sysfs creation failed
");
return -EINVAL;
}
// --------------------------------------
//QDECCTL
// Read decoder control settings
status = readw(eqep->mmio_base + QDECCTL);
status = status & 0x3fff;//
// Write the decoder control settings back to the control register
writew(status, eqep->mmio_base + QDECCTL);
//QPOSINIT
// Initialize the position counter to zero
writel(0, eqep->mmio_base + QPOSINIT);
//QPOSMAX
writel(0xffffffff, eqep->mmio_base + QPOSMAX);
//QEINT
// Enable some interrupts
status = readw(eqep->mmio_base + QEINT);
status = status | UTOF;
// UTOF - Unit Time Period interrupt. This is triggered when the unit timer period expires
//
writew(status, eqep->mmio_base + QEINT);
// Calculate the timer ticks per second
period = 1000000000;
period = period * eqep->clk_rate;
do_div(period, NSEC_PER_SEC);
//QUPRD
// Set this period into the unit timer period register
writel(period & 0x00000000FFFFFFFF, eqep->mmio_base + QUPRD);
//QEPCTL
// Enable the eQEP with basic position counting turned on
status = readw(eqep->mmio_base + QEPCTL);
status = (status& 0x3fff) |0x8000;
status = status & 0xcfff;
status = status | 0x0002;
status = status | 0x0004;
status = status | 0x0008;
writew(status, eqep->mmio_base + QEPCTL);
//QCAPCTL
status = readw(eqep->mmio_base + QCAPCTL);
status = status & (~0x8000);
status = (status& 0xfff0) |0x0005;
status = (status& 0xff8f) |0x0060;
status = status | 0x8000;
writew(status, eqep->mmio_base + QCAPCTL);
//----------------------------------------------------------------------------
// We default to absolute mode
eqep->mode = TIEQEP_MODE_ABSOLUTE;
// Enable the power management runtime
pm_runtime_enable(&pdev->dev);
// Increment the device usage count and run pm_runtime_resume()
pm_runtime_get_sync(&pdev->dev);
// Enable the clock to the eQEP unit
status = pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EQEPCLK_EN);
// If we failed to enable the clocks, fail out
if (!(status & PWMSS_EQEPCLK_EN_ACK))
{
dev_err(&pdev->dev, "PWMSS config space clock enable failed
");
ret = -EINVAL;
goto pwmss_clk_failure;
}
// Initialize the notify work struture
INIT_WORK(&eqep->notify_work, notify_handler);
// Decrement the device usage count (twice) and run pm_runtime_idle() if zero
pm_runtime_put_sync(&pdev->dev);
// Set the platform driver data to the data object we've been creating for the eQEP unit
platform_set_drvdata(pdev, eqep);
// Success!
//printk(KERN_INFO "EQEP irq = %d, system clock = %u
", eqep->irq, eqep->clk_rate);
return 0;
// If a failure occurred, stop the runtime power management
pwmss_clk_failure:
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return ret;
}
// Remove an instance of the eQEP driver
static int eqep_remove(struct platform_device *pdev)
{
// Get the eQEP driver data from the platform device structure
struct eqep_chip *eqep = platform_get_drvdata(pdev);
// Cancel work
cancel_work_sync(&eqep->notify_work);
// Unmap from sysfs
sysfs_remove_group(&pdev->dev.kobj, &eqep_device_attr_group);
// Release important assets
free_irq(eqep->irq, pdev);
// Increment the device usage count and run pm_runtime_resume()
pm_runtime_get_sync(&pdev->dev);
// Disable the eQEP clock
pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EQEPCLK_STOP_REQ);
// Decrement the device usage count (twice) and run pm_runtime_idle() if zero
pm_runtime_put_sync(&pdev->dev);
pm_runtime_put_sync(&pdev->dev);
// Disable the runtime power management of this device
pm_runtime_disable(&pdev->dev);
// Return success
return 0;
}
// Power management suspend device
static int eqep_suspend(struct device *dev)
{
// Get the eqep driver information
struct eqep_chip *eqep = dev_get_drvdata(dev);
u16 tmp;
// Shut down interrupts
eqep->prior_qeint = readw(eqep->mmio_base + QEINT);
tmp = eqep->prior_qeint & ~UTOF;
// UTOF - Unit Time Period interrupt.
writew(tmp, eqep->mmio_base + QEINT);
// Get the existing state of QEPCTL
eqep->prior_qepctl = readw(eqep->mmio_base + QEPCTL);
// Disable eQEP controller
writew(eqep->prior_qepctl & ~PHEN, eqep->mmio_base + QEPCTL);
// Decrement the device usage count and run pm_runtime_idle() if zero
pm_runtime_put_sync(dev);
// Return success
return 0;
}
// Power management wake device back up
static int eqep_resume(struct device *dev)
{
// Get the eqep driver information
struct eqep_chip *eqep = dev_get_drvdata(dev);
// Restore interrupt enabled register
writew(eqep->prior_qeint, eqep->mmio_base + QEINT);
// Restore prior qep control register
writew(eqep->prior_qepctl, eqep->mmio_base + QEPCTL);
// Increment the device usage count and run pm_runtime_resume()
pm_runtime_get_sync(dev);
// Success
return 0;
}
// create pm functions object
static SIMPLE_DEV_PM_OPS(eqep_pm_ops, eqep_suspend, eqep_resume);
// Platform driver information
static struct platform_driver eqep_driver = {
.driver = {
.name = "eqep",
.owner = THIS_MODULE,
.pm = &eqep_pm_ops,
.of_match_table = eqep_of_match,
},
.probe = eqep_probe,
.remove = eqep_remove,
};
// Register this platform driver
module_platform_driver(eqep_driver);
// Module information
MODULE_DESCRIPTION("TI eQEP driver");
MODULE_AUTHOR("Nathaniel R. Lewis");
MODULE_LICENSE("GPL");
makefileの追加
obj-$(CONFIG_TIEQEP) += tieqep.o
Kconfigファイルの追加
menuconfig QEP
bool "QEP Support"
help
Generic QEP support.
config TIEQEP
tristate "first module"
depends on ARM
default y
これによりlinux-master/drivers/qepフォルダの下に3つのファイルlinux-master/drivers/qep/tieqepがある.c linux-master/drivers/qep/makefile linux-master/drivers/qep/Kconfigの3つのファイル2.前のレベルのディレクトリのlinux-master/drivers/makefile追加
obj-y += qep/
linux-master/drivers/Kconfig追加
source "drivers/qep/Kconfig"
3.linux-master/Kconfigで追加
source "drivers/qep/Kconfig"
4.次にmake menuconfigでカーネル*make zImageコンパイル5にコンパイルすることを選択する.問題は、開発ボードコンソールに入ると、/sys/classでqepという駆動フォルダが表示されません.
すみません、ドライバコードに問題があるのか、makeプロセスに問題があるのか、それともカーネルにコンパイルされたのは位置エラーなのか.