diff options
Diffstat (limited to 'drivers/spi/spidev.c')
| -rw-r--r-- | drivers/spi/spidev.c | 322 |
1 files changed, 188 insertions, 134 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index d753df700e9e..9a0160f6dc3d 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -8,19 +8,18 @@ */ #include <linux/init.h> -#include <linux/module.h> #include <linux/ioctl.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/err.h> #include <linux/list.h> #include <linux/errno.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> #include <linux/mutex.h> +#include <linux/property.h> #include <linux/slab.h> #include <linux/compat.h> -#include <linux/of.h> -#include <linux/of_device.h> -#include <linux/acpi.h> #include <linux/spi/spi.h> #include <linux/spi/spidev.h> @@ -46,6 +45,7 @@ static DECLARE_BITMAP(minors, N_SPI_MINORS); +static_assert(N_SPI_MINORS > 0 && N_SPI_MINORS <= 256); /* Bit masks for spi_device.mode management. Note that incorrect * settings for some settings can cause *lots* of trouble for other @@ -59,15 +59,17 @@ static DECLARE_BITMAP(minors, N_SPI_MINORS); * * REVISIT should changing those flags be privileged? */ -#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \ +#define SPI_MODE_MASK (SPI_MODE_X_MASK | SPI_CS_HIGH \ | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \ | SPI_NO_CS | SPI_READY | SPI_TX_DUAL \ | SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL \ - | SPI_RX_QUAD | SPI_RX_OCTAL) + | SPI_RX_QUAD | SPI_RX_OCTAL \ + | SPI_RX_CPHA_FLIP | SPI_3WIRE_HIZ \ + | SPI_MOSI_IDLE_LOW) struct spidev_data { dev_t devt; - spinlock_t spi_lock; + struct mutex spi_lock; struct spi_device *spi; struct list_head device_entry; @@ -89,23 +91,32 @@ MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); /*-------------------------------------------------------------------------*/ static ssize_t +spidev_sync_unlocked(struct spi_device *spi, struct spi_message *message) +{ + ssize_t status; + + status = spi_sync(spi, message); + if (status == 0) + status = message->actual_length; + + return status; +} + +static ssize_t spidev_sync(struct spidev_data *spidev, struct spi_message *message) { - int status; + ssize_t status; struct spi_device *spi; - spin_lock_irq(&spidev->spi_lock); + mutex_lock(&spidev->spi_lock); spi = spidev->spi; - spin_unlock_irq(&spidev->spi_lock); if (spi == NULL) status = -ESHUTDOWN; else - status = spi_sync(spi, message); - - if (status == 0) - status = message->actual_length; + status = spidev_sync_unlocked(spi, message); + mutex_unlock(&spidev->spi_lock); return status; } @@ -146,7 +157,7 @@ static ssize_t spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) { struct spidev_data *spidev; - ssize_t status = 0; + ssize_t status; /* chipselect only toggles at start or end of operation */ if (count > bufsiz) @@ -176,7 +187,7 @@ spidev_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { struct spidev_data *spidev; - ssize_t status = 0; + ssize_t status; unsigned long missing; /* chipselect only toggles at start or end of operation */ @@ -224,6 +235,11 @@ static int spidev_message(struct spidev_data *spidev, for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; n; n--, k_tmp++, u_tmp++) { + /* Ensure that also following allocations from rx_buf/tx_buf will meet + * DMA alignment requirements. + */ + unsigned int len_aligned = ALIGN(u_tmp->len, ARCH_DMA_MINALIGN); + k_tmp->len = u_tmp->len; total += k_tmp->len; @@ -239,17 +255,17 @@ static int spidev_message(struct spidev_data *spidev, if (u_tmp->rx_buf) { /* this transfer needs space in RX bounce buffer */ - rx_total += k_tmp->len; + rx_total += len_aligned; if (rx_total > bufsiz) { status = -EMSGSIZE; goto done; } k_tmp->rx_buf = rx_buf; - rx_buf += k_tmp->len; + rx_buf += len_aligned; } if (u_tmp->tx_buf) { /* this transfer needs space in TX bounce buffer */ - tx_total += k_tmp->len; + tx_total += len_aligned; if (tx_total > bufsiz) { status = -EMSGSIZE; goto done; @@ -259,7 +275,7 @@ static int spidev_message(struct spidev_data *spidev, (uintptr_t) u_tmp->tx_buf, u_tmp->len)) goto done; - tx_buf += k_tmp->len; + tx_buf += len_aligned; } k_tmp->cs_change = !!u_tmp->cs_change; @@ -288,21 +304,21 @@ static int spidev_message(struct spidev_data *spidev, spi_message_add_tail(k_tmp, &msg); } - status = spidev_sync(spidev, &msg); + status = spidev_sync_unlocked(spidev->spi, &msg); if (status < 0) goto done; /* copy any rx data out of bounce buffer */ - rx_buf = spidev->rx_buffer; - for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { + for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; + n; + n--, k_tmp++, u_tmp++) { if (u_tmp->rx_buf) { if (copy_to_user((u8 __user *) - (uintptr_t) u_tmp->rx_buf, rx_buf, + (uintptr_t) u_tmp->rx_buf, k_tmp->rx_buf, u_tmp->len)) { status = -EFAULT; goto done; } - rx_buf += u_tmp->len; } } status = total; @@ -341,6 +357,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) int retval = 0; struct spidev_data *spidev; struct spi_device *spi; + struct spi_controller *ctlr; u32 tmp; unsigned n_ioc; struct spi_ioc_transfer *ioc; @@ -353,12 +370,14 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) * we issue this ioctl. */ spidev = filp->private_data; - spin_lock_irq(&spidev->spi_lock); + mutex_lock(&spidev->spi_lock); spi = spi_dev_get(spidev->spi); - spin_unlock_irq(&spidev->spi_lock); - - if (spi == NULL) + if (spi == NULL) { + mutex_unlock(&spidev->spi_lock); return -ESHUTDOWN; + } + + ctlr = spi->controller; /* use the buffer lock here for triple duty: * - prevent I/O (from us) so calling spi_setup() is safe; @@ -371,12 +390,16 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) switch (cmd) { /* read requests */ case SPI_IOC_RD_MODE: - retval = put_user(spi->mode & SPI_MODE_MASK, - (__u8 __user *)arg); - break; case SPI_IOC_RD_MODE32: - retval = put_user(spi->mode & SPI_MODE_MASK, - (__u32 __user *)arg); + tmp = spi->mode & SPI_MODE_MASK; + + if (ctlr->use_gpio_descriptors && spi_get_csgpiod(spi, 0)) + tmp &= ~SPI_CS_HIGH; + + if (cmd == SPI_IOC_RD_MODE) + retval = put_user(tmp, (__u8 __user *)arg); + else + retval = put_user(tmp, (__u32 __user *)arg); break; case SPI_IOC_RD_LSB_FIRST: retval = put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0, @@ -397,7 +420,6 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) else retval = get_user(tmp, (u32 __user *)arg); if (retval == 0) { - struct spi_controller *ctlr = spi->controller; u32 save = spi->mode; if (tmp & ~SPI_MODE_MASK) { @@ -405,12 +427,11 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) break; } - if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods && - ctlr->cs_gpiods[spi->chip_select]) + if (ctlr->use_gpio_descriptors && spi_get_csgpiod(spi, 0)) tmp |= SPI_CS_HIGH; tmp |= spi->mode & ~SPI_MODE_MASK; - spi->mode = (u16)tmp; + spi->mode = tmp & SPI_MODE_USER_MASK; retval = spi_setup(spi); if (retval < 0) spi->mode = save; @@ -448,22 +469,29 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) dev_dbg(&spi->dev, "%d bits per word\n", tmp); } break; - case SPI_IOC_WR_MAX_SPEED_HZ: + case SPI_IOC_WR_MAX_SPEED_HZ: { + u32 save; + retval = get_user(tmp, (__u32 __user *)arg); - if (retval == 0) { - u32 save = spi->max_speed_hz; + if (retval) + break; + if (tmp == 0) { + retval = -EINVAL; + break; + } - spi->max_speed_hz = tmp; - retval = spi_setup(spi); - if (retval == 0) { - spidev->speed_hz = tmp; - dev_dbg(&spi->dev, "%d Hz (max)\n", - spidev->speed_hz); - } - spi->max_speed_hz = save; + save = spi->max_speed_hz; + + spi->max_speed_hz = tmp; + retval = spi_setup(spi); + if (retval == 0) { + spidev->speed_hz = tmp; + dev_dbg(&spi->dev, "%d Hz (max)\n", spidev->speed_hz); } - break; + spi->max_speed_hz = save; + break; + } default: /* segmented and/or full-duplex I/O request */ /* Check message and copy into scratch area */ @@ -484,6 +512,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) mutex_unlock(&spidev->buf_lock); spi_dev_put(spi); + mutex_unlock(&spidev->spi_lock); return retval; } @@ -505,12 +534,12 @@ spidev_compat_ioc_message(struct file *filp, unsigned int cmd, * we issue this ioctl. */ spidev = filp->private_data; - spin_lock_irq(&spidev->spi_lock); + mutex_lock(&spidev->spi_lock); spi = spi_dev_get(spidev->spi); - spin_unlock_irq(&spidev->spi_lock); - - if (spi == NULL) + if (spi == NULL) { + mutex_unlock(&spidev->spi_lock); return -ESHUTDOWN; + } /* SPI_IOC_MESSAGE needs the buffer locked "normally" */ mutex_lock(&spidev->buf_lock); @@ -537,6 +566,7 @@ spidev_compat_ioc_message(struct file *filp, unsigned int cmd, done: mutex_unlock(&spidev->buf_lock); spi_dev_put(spi); + mutex_unlock(&spidev->spi_lock); return retval; } @@ -556,19 +586,20 @@ spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) static int spidev_open(struct inode *inode, struct file *filp) { - struct spidev_data *spidev; + struct spidev_data *spidev = NULL, *iter; int status = -ENXIO; mutex_lock(&device_list_lock); - list_for_each_entry(spidev, &device_list, device_entry) { - if (spidev->devt == inode->i_rdev) { + list_for_each_entry(iter, &device_list, device_entry) { + if (iter->devt == inode->i_rdev) { status = 0; + spidev = iter; break; } } - if (status) { + if (!spidev) { pr_debug("spidev: nothing for minor %d\n", iminor(inode)); goto err_find_dev; } @@ -576,7 +607,6 @@ static int spidev_open(struct inode *inode, struct file *filp) if (!spidev->tx_buffer) { spidev->tx_buffer = kmalloc(bufsiz, GFP_KERNEL); if (!spidev->tx_buffer) { - dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); status = -ENOMEM; goto err_find_dev; } @@ -585,7 +615,6 @@ static int spidev_open(struct inode *inode, struct file *filp) if (!spidev->rx_buffer) { spidev->rx_buffer = kmalloc(bufsiz, GFP_KERNEL); if (!spidev->rx_buffer) { - dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); status = -ENOMEM; goto err_alloc_rx_buf; } @@ -609,15 +638,20 @@ err_find_dev: static int spidev_release(struct inode *inode, struct file *filp) { struct spidev_data *spidev; + int dofree; mutex_lock(&device_list_lock); spidev = filp->private_data; filp->private_data = NULL; + mutex_lock(&spidev->spi_lock); + /* ... after we unbound from the underlying device? */ + dofree = (spidev->spi == NULL); + mutex_unlock(&spidev->spi_lock); + /* last close? */ spidev->users--; if (!spidev->users) { - int dofree; kfree(spidev->tx_buffer); spidev->tx_buffer = NULL; @@ -625,19 +659,14 @@ static int spidev_release(struct inode *inode, struct file *filp) kfree(spidev->rx_buffer); spidev->rx_buffer = NULL; - spin_lock_irq(&spidev->spi_lock); - if (spidev->spi) - spidev->speed_hz = spidev->spi->max_speed_hz; - - /* ... after we unbound from the underlying device? */ - dofree = (spidev->spi == NULL); - spin_unlock_irq(&spidev->spi_lock); - if (dofree) kfree(spidev); + else + spidev->speed_hz = spidev->spi->max_speed_hz; } #ifdef CONFIG_SPI_SLAVE - spi_slave_abort(spidev->spi); + if (!dofree) + spi_target_abort(spidev->spi); #endif mutex_unlock(&device_list_lock); @@ -656,7 +685,6 @@ static const struct file_operations spidev_fops = { .compat_ioctl = spidev_compat_ioctl, .open = spidev_open, .release = spidev_release, - .llseek = no_llseek, }; /*-------------------------------------------------------------------------*/ @@ -666,26 +694,75 @@ static const struct file_operations spidev_fops = { * It also simplifies memory management. */ -static struct class *spidev_class; +static const struct class spidev_class = { + .name = "spidev", +}; + +/* + * The spi device ids are expected to match the device names of the + * spidev_dt_ids array below. Both arrays are kept in the same ordering. + */ +static const struct spi_device_id spidev_spi_ids[] = { + { .name = /* abb */ "spi-sensor" }, + { .name = /* arduino */ "unoq-mcu" }, + { .name = /* cisco */ "spi-petra" }, + { .name = /* dh */ "dhcom-board" }, + { .name = /* elgin */ "jg10309-01" }, + { .name = /* gocontroll */ "moduline-module-slot"}, + { .name = /* lineartechnology */ "ltc2488" }, + { .name = /* lwn */ "bk4" }, + { .name = /* lwn */ "bk4-spi" }, + { .name = /* menlo */ "m53cpld" }, + { .name = /* micron */ "spi-authenta" }, + { .name = /* rohm */ "bh2228fv" }, + { .name = /* rohm */ "dh2228fv" }, + { .name = /* semtech */ "sx1301" }, + { .name = /* silabs */ "em3581" }, + { .name = /* silabs */ "si3210" }, + {}, +}; +MODULE_DEVICE_TABLE(spi, spidev_spi_ids); + +/* + * spidev should never be referenced in DT without a specific compatible string, + * it is a Linux implementation thing rather than a description of the hardware. + */ +static int spidev_of_check(struct device *dev) +{ + if (device_property_match_string(dev, "compatible", "spidev") < 0) + return 0; + + dev_err(dev, "spidev listed directly in DT is not supported\n"); + return -EINVAL; +} -#ifdef CONFIG_OF static const struct of_device_id spidev_dt_ids[] = { - { .compatible = "rohm,dh2228fv" }, - { .compatible = "lineartechnology,ltc2488" }, - { .compatible = "ge,achc" }, - { .compatible = "semtech,sx1301" }, - { .compatible = "lwn,bk4" }, - { .compatible = "dh,dhcom-board" }, - { .compatible = "menlo,m53cpld" }, + { .compatible = "abb,spi-sensor", .data = &spidev_of_check }, + { .compatible = "arduino,unoq-mcu", .data = &spidev_of_check }, + { .compatible = "cisco,spi-petra", .data = &spidev_of_check }, + { .compatible = "dh,dhcom-board", .data = &spidev_of_check }, + { .compatible = "elgin,jg10309-01", .data = &spidev_of_check }, + { .compatible = "gocontroll,moduline-module-slot", .data = &spidev_of_check}, + { .compatible = "lineartechnology,ltc2488", .data = &spidev_of_check }, + { .compatible = "lwn,bk4", .data = &spidev_of_check }, + { .compatible = "lwn,bk4-spi", .data = &spidev_of_check }, + { .compatible = "menlo,m53cpld", .data = &spidev_of_check }, + { .compatible = "micron,spi-authenta", .data = &spidev_of_check }, + { .compatible = "rohm,bh2228fv", .data = &spidev_of_check }, + { .compatible = "rohm,dh2228fv", .data = &spidev_of_check }, + { .compatible = "semtech,sx1301", .data = &spidev_of_check }, + { .compatible = "silabs,em3581", .data = &spidev_of_check }, + { .compatible = "silabs,si3210", .data = &spidev_of_check }, {}, }; MODULE_DEVICE_TABLE(of, spidev_dt_ids); -#endif - -#ifdef CONFIG_ACPI /* Dummy SPI devices not to be used in production systems */ -#define SPIDEV_ACPI_DUMMY 1 +static int spidev_acpi_check(struct device *dev) +{ + dev_warn(dev, "do not use this driver in production systems!\n"); + return 0; +} static const struct acpi_device_id spidev_acpi_ids[] = { /* @@ -694,49 +771,28 @@ static const struct acpi_device_id spidev_acpi_ids[] = { * description of the connected peripheral and they should also use * a proper driver instead of poking directly to the SPI bus. */ - { "SPT0001", SPIDEV_ACPI_DUMMY }, - { "SPT0002", SPIDEV_ACPI_DUMMY }, - { "SPT0003", SPIDEV_ACPI_DUMMY }, + { "SPT0001", (kernel_ulong_t)&spidev_acpi_check }, + { "SPT0002", (kernel_ulong_t)&spidev_acpi_check }, + { "SPT0003", (kernel_ulong_t)&spidev_acpi_check }, {}, }; MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids); -static void spidev_probe_acpi(struct spi_device *spi) -{ - const struct acpi_device_id *id; - - if (!has_acpi_companion(&spi->dev)) - return; - - id = acpi_match_device(spidev_acpi_ids, &spi->dev); - if (WARN_ON(!id)) - return; - - if (id->driver_data == SPIDEV_ACPI_DUMMY) - dev_warn(&spi->dev, "do not use this driver in production systems!\n"); -} -#else -static inline void spidev_probe_acpi(struct spi_device *spi) {} -#endif - /*-------------------------------------------------------------------------*/ static int spidev_probe(struct spi_device *spi) { + int (*match)(struct device *dev); struct spidev_data *spidev; int status; unsigned long minor; - /* - * spidev should never be referenced in DT without a specific - * compatible string, it is a Linux implementation thing - * rather than a description of the hardware. - */ - WARN(spi->dev.of_node && - of_device_is_compatible(spi->dev.of_node, "spidev"), - "%pOF: buggy DT: spidev listed directly in DT\n", spi->dev.of_node); - - spidev_probe_acpi(spi); + match = device_get_match_data(&spi->dev); + if (match) { + status = match(&spi->dev); + if (status) + return status; + } /* Allocate driver data */ spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); @@ -745,7 +801,7 @@ static int spidev_probe(struct spi_device *spi) /* Initialize the driver data */ spidev->spi = spi; - spin_lock_init(&spidev->spi_lock); + mutex_init(&spidev->spi_lock); mutex_init(&spidev->buf_lock); INIT_LIST_HEAD(&spidev->device_entry); @@ -759,9 +815,9 @@ static int spidev_probe(struct spi_device *spi) struct device *dev; spidev->devt = MKDEV(SPIDEV_MAJOR, minor); - dev = device_create(spidev_class, &spi->dev, spidev->devt, + dev = device_create(&spidev_class, &spi->dev, spidev->devt, spidev, "spidev%d.%d", - spi->master->bus_num, spi->chip_select); + spi->controller->bus_num, spi_get_chipselect(spi, 0)); status = PTR_ERR_OR_ZERO(dev); } else { dev_dbg(&spi->dev, "no minor number available!\n"); @@ -783,35 +839,34 @@ static int spidev_probe(struct spi_device *spi) return status; } -static int spidev_remove(struct spi_device *spi) +static void spidev_remove(struct spi_device *spi) { struct spidev_data *spidev = spi_get_drvdata(spi); + /* prevent new opens */ + mutex_lock(&device_list_lock); /* make sure ops on existing fds can abort cleanly */ - spin_lock_irq(&spidev->spi_lock); + mutex_lock(&spidev->spi_lock); spidev->spi = NULL; - spin_unlock_irq(&spidev->spi_lock); + mutex_unlock(&spidev->spi_lock); - /* prevent new opens */ - mutex_lock(&device_list_lock); list_del(&spidev->device_entry); - device_destroy(spidev_class, spidev->devt); + device_destroy(&spidev_class, spidev->devt); clear_bit(MINOR(spidev->devt), minors); if (spidev->users == 0) kfree(spidev); mutex_unlock(&device_list_lock); - - return 0; } static struct spi_driver spidev_spi_driver = { .driver = { .name = "spidev", - .of_match_table = of_match_ptr(spidev_dt_ids), - .acpi_match_table = ACPI_PTR(spidev_acpi_ids), + .of_match_table = spidev_dt_ids, + .acpi_match_table = spidev_acpi_ids, }, .probe = spidev_probe, .remove = spidev_remove, + .id_table = spidev_spi_ids, /* NOTE: suspend/resume methods are not necessary here. * We don't do anything except pass the requests to/from @@ -830,20 +885,19 @@ static int __init spidev_init(void) * that will key udev/mdev to add/remove /dev nodes. Last, register * the driver which manages those device numbers. */ - BUILD_BUG_ON(N_SPI_MINORS > 256); status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops); if (status < 0) return status; - spidev_class = class_create(THIS_MODULE, "spidev"); - if (IS_ERR(spidev_class)) { + status = class_register(&spidev_class); + if (status) { unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); - return PTR_ERR(spidev_class); + return status; } status = spi_register_driver(&spidev_spi_driver); if (status < 0) { - class_destroy(spidev_class); + class_unregister(&spidev_class); unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); } return status; @@ -853,7 +907,7 @@ module_init(spidev_init); static void __exit spidev_exit(void) { spi_unregister_driver(&spidev_spi_driver); - class_destroy(spidev_class); + class_unregister(&spidev_class); unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); } module_exit(spidev_exit); |
