diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi_imx.c | 54 | ||||
| -rw-r--r-- | drivers/spi/spidev.c | 179 |
2 files changed, 166 insertions, 67 deletions
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c index c730d05bfeb..54ac7bea5f8 100644 --- a/drivers/spi/spi_imx.c +++ b/drivers/spi/spi_imx.c @@ -29,6 +29,7 @@ #include <linux/spi/spi.h> #include <linux/workqueue.h> #include <linux/delay.h> +#include <linux/clk.h> #include <asm/io.h> #include <asm/irq.h> @@ -250,6 +251,8 @@ struct driver_data { int tx_dma_needs_unmap; size_t tx_map_len; u32 dummy_dma_buf ____cacheline_aligned; + + struct clk *clk; }; /* Runtime state */ @@ -855,15 +858,15 @@ static irqreturn_t spi_int(int irq, void *dev_id) return drv_data->transfer_handler(drv_data); } -static inline u32 spi_speed_hz(u32 data_rate) +static inline u32 spi_speed_hz(struct driver_data *drv_data, u32 data_rate) { - return imx_get_perclk2() / (4 << ((data_rate) >> 13)); + return clk_get_rate(drv_data->clk) / (4 << ((data_rate) >> 13)); } -static u32 spi_data_rate(u32 speed_hz) +static u32 spi_data_rate(struct driver_data *drv_data, u32 speed_hz) { u32 div; - u32 quantized_hz = imx_get_perclk2() >> 2; + u32 quantized_hz = clk_get_rate(drv_data->clk) >> 2; for (div = SPI_PERCLK2_DIV_MIN; div <= SPI_PERCLK2_DIV_MAX; @@ -947,7 +950,7 @@ static void pump_transfers(unsigned long data) tmp = transfer->speed_hz; if (tmp == 0) tmp = chip->max_speed_hz; - tmp = spi_data_rate(tmp); + tmp = spi_data_rate(drv_data, tmp); u32_EDIT(control, SPI_CONTROL_DATARATE, tmp); writel(control, regs + SPI_CONTROL); @@ -1109,7 +1112,7 @@ static int transfer(struct spi_device *spi, struct spi_message *msg) msg->actual_length = 0; /* Per transfer setup check */ - min_speed_hz = spi_speed_hz(SPI_CONTROL_DATARATE_MIN); + min_speed_hz = spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN); max_speed_hz = spi->max_speed_hz; list_for_each_entry(trans, &msg->transfers, transfer_list) { tmp = trans->bits_per_word; @@ -1176,6 +1179,7 @@ msg_rejected: applied and notified to the calling driver. */ static int setup(struct spi_device *spi) { + struct driver_data *drv_data = spi_master_get_devdata(spi->master); struct spi_imx_chip *chip_info; struct chip_data *chip; int first_setup = 0; @@ -1304,14 +1308,14 @@ static int setup(struct spi_device *spi) chip->n_bytes = (tmp <= 8) ? 1 : 2; /* SPI datarate */ - tmp = spi_data_rate(spi->max_speed_hz); + tmp = spi_data_rate(drv_data, spi->max_speed_hz); if (tmp == SPI_CONTROL_DATARATE_BAD) { status = -EINVAL; dev_err(&spi->dev, "setup - " "HW min speed (%d Hz) exceeds required " "max speed (%d Hz)\n", - spi_speed_hz(SPI_CONTROL_DATARATE_MIN), + spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN), spi->max_speed_hz); if (first_setup) goto err_first_setup; @@ -1321,7 +1325,7 @@ static int setup(struct spi_device *spi) } else { u32_EDIT(chip->control, SPI_CONTROL_DATARATE, tmp); /* Actual rounded max_speed_hz */ - tmp = spi_speed_hz(tmp); + tmp = spi_speed_hz(drv_data, tmp); spi->max_speed_hz = tmp; chip->max_speed_hz = tmp; } @@ -1352,7 +1356,7 @@ static int setup(struct spi_device *spi) chip->period & SPI_PERIOD_WAIT, spi->mode, spi->bits_per_word, - spi_speed_hz(SPI_CONTROL_DATARATE_MIN), + spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN), spi->max_speed_hz); return status; @@ -1465,6 +1469,14 @@ static int __init spi_imx_probe(struct platform_device *pdev) goto err_no_pdata; } + drv_data->clk = clk_get(&pdev->dev, "perclk2"); + if (IS_ERR(drv_data->clk)) { + dev_err(&pdev->dev, "probe - cannot get get\n"); + status = PTR_ERR(drv_data->clk); + goto err_no_clk; + } + clk_enable(drv_data->clk); + /* Allocate master with space for drv_data */ master = spi_alloc_master(dev, sizeof(struct driver_data)); if (!master) { @@ -1526,24 +1538,24 @@ static int __init spi_imx_probe(struct platform_device *pdev) drv_data->rx_channel = -1; if (platform_info->enable_dma) { /* Get rx DMA channel */ - status = imx_dma_request_by_prio(&drv_data->rx_channel, - "spi_imx_rx", DMA_PRIO_HIGH); - if (status < 0) { + drv_data->rx_channel = imx_dma_request_by_prio("spi_imx_rx", + DMA_PRIO_HIGH); + if (drv_data->rx_channel < 0) { dev_err(dev, "probe - problem (%d) requesting rx channel\n", - status); + drv_data->rx_channel); goto err_no_rxdma; } else imx_dma_setup_handlers(drv_data->rx_channel, NULL, dma_err_handler, drv_data); /* Get tx DMA channel */ - status = imx_dma_request_by_prio(&drv_data->tx_channel, - "spi_imx_tx", DMA_PRIO_MEDIUM); - if (status < 0) { + drv_data->tx_channel = imx_dma_request_by_prio("spi_imx_tx", + DMA_PRIO_MEDIUM); + if (drv_data->tx_channel < 0) { dev_err(dev, "probe - problem (%d) requesting tx channel\n", - status); + drv_data->tx_channel); imx_dma_free(drv_data->rx_channel); goto err_no_txdma; } else @@ -1623,6 +1635,9 @@ err_no_iores: spi_master_put(master); err_no_pdata: + clk_disable(drv_data->clk); + clk_put(drv_data->clk); +err_no_clk: err_no_mem: return status; } @@ -1662,6 +1677,9 @@ static int __exit spi_imx_remove(struct platform_device *pdev) if (irq >= 0) free_irq(irq, drv_data); + clk_disable(drv_data->clk); + clk_put(drv_data->clk); + /* Release map resources */ iounmap(drv_data->regs); release_resource(drv_data->ioarea); diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index b3518ca9f04..ddbe1a5e970 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -25,10 +25,12 @@ #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/mutex.h> #include <linux/slab.h> +#include <linux/smp_lock.h> #include <linux/spi/spi.h> #include <linux/spi/spidev.h> @@ -67,10 +69,12 @@ static unsigned long minors[N_SPI_MINORS / BITS_PER_LONG]; | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP) struct spidev_data { - struct device dev; + dev_t devt; + spinlock_t spi_lock; struct spi_device *spi; struct list_head device_entry; + /* buffer is NULL unless this device is open (users > 0) */ struct mutex buf_lock; unsigned users; u8 *buffer; @@ -85,12 +89,75 @@ MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); /*-------------------------------------------------------------------------*/ +/* + * We can't use the standard synchronous wrappers for file I/O; we + * need to protect against async removal of the underlying spi_device. + */ +static void spidev_complete(void *arg) +{ + complete(arg); +} + +static ssize_t +spidev_sync(struct spidev_data *spidev, struct spi_message *message) +{ + DECLARE_COMPLETION_ONSTACK(done); + int status; + + message->complete = spidev_complete; + message->context = &done; + + spin_lock_irq(&spidev->spi_lock); + if (spidev->spi == NULL) + status = -ESHUTDOWN; + else + status = spi_async(spidev->spi, message); + spin_unlock_irq(&spidev->spi_lock); + + if (status == 0) { + wait_for_completion(&done); + status = message->status; + if (status == 0) + status = message->actual_length; + } + return status; +} + +static inline ssize_t +spidev_sync_write(struct spidev_data *spidev, size_t len) +{ + struct spi_transfer t = { + .tx_buf = spidev->buffer, + .len = len, + }; + struct spi_message m; + + spi_message_init(&m); + spi_message_add_tail(&t, &m); + return spidev_sync(spidev, &m); +} + +static inline ssize_t +spidev_sync_read(struct spidev_data *spidev, size_t len) +{ + struct spi_transfer t = { + .rx_buf = spidev->buffer, + .len = len, + }; + struct spi_message m; + + spi_message_init(&m); + spi_message_add_tail(&t, &m); + return spidev_sync(spidev, &m); +} + +/*-------------------------------------------------------------------------*/ + /* Read-only message with current device setup */ static ssize_t spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) { struct spidev_data *spidev; - struct spi_device *spi; ssize_t status = 0; /* chipselect only toggles at start or end of operation */ @@ -98,18 +165,17 @@ spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) return -EMSGSIZE; spidev = filp->private_data; - spi = spidev->spi; mutex_lock(&spidev->buf_lock); - status = spi_read(spi, spidev->buffer, count); - if (status == 0) { + status = spidev_sync_read(spidev, count); + if (status > 0) { unsigned long missing; - missing = copy_to_user(buf, spidev->buffer, count); - if (count && missing == count) + missing = copy_to_user(buf, spidev->buffer, status); + if (missing == status) status = -EFAULT; else - status = count - missing; + status = status - missing; } mutex_unlock(&spidev->buf_lock); @@ -122,7 +188,6 @@ spidev_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { struct spidev_data *spidev; - struct spi_device *spi; ssize_t status = 0; unsigned long missing; @@ -131,14 +196,11 @@ spidev_write(struct file *filp, const char __user *buf, return -EMSGSIZE; spidev = filp->private_data; - spi = spidev->spi; mutex_lock(&spidev->buf_lock); missing = copy_from_user(spidev->buffer, buf, count); if (missing == 0) { - status = spi_write(spi, spidev->buffer, count); - if (status == 0) - status = count; + status = spidev_sync_write(spidev, count); } else status = -EFAULT; mutex_unlock(&spidev->buf_lock); @@ -153,7 +215,6 @@ static int spidev_message(struct spidev_data *spidev, struct spi_transfer *k_xfers; struct spi_transfer *k_tmp; struct spi_ioc_transfer *u_tmp; - struct spi_device *spi = spidev->spi; unsigned n, total; u8 *buf; int status = -EFAULT; @@ -215,7 +276,7 @@ static int spidev_message(struct spidev_data *spidev, spi_message_add_tail(k_tmp, &msg); } - status = spi_sync(spi, &msg); + status = spidev_sync(spidev, &msg); if (status < 0) goto done; @@ -269,8 +330,16 @@ spidev_ioctl(struct inode *inode, struct file *filp, if (err) return -EFAULT; + /* guard against device removal before, or while, + * we issue this ioctl. + */ spidev = filp->private_data; - spi = spidev->spi; + spin_lock_irq(&spidev->spi_lock); + spi = spi_dev_get(spidev->spi); + spin_unlock_irq(&spidev->spi_lock); + + if (spi == NULL) + return -ESHUTDOWN; switch (cmd) { /* read requests */ @@ -356,8 +425,10 @@ spidev_ioctl(struct inode *inode, struct file *filp, default: /* segmented and/or full-duplex I/O request */ if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0)) - || _IOC_DIR(cmd) != _IOC_WRITE) - return -ENOTTY; + || _IOC_DIR(cmd) != _IOC_WRITE) { + retval = -ENOTTY; + break; + } tmp = _IOC_SIZE(cmd); if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) { @@ -385,6 +456,7 @@ spidev_ioctl(struct inode *inode, struct file *filp, kfree(ioc); break; } + spi_dev_put(spi); return retval; } @@ -393,10 +465,11 @@ static int spidev_open(struct inode *inode, struct file *filp) struct spidev_data *spidev; int status = -ENXIO; + lock_kernel(); mutex_lock(&device_list_lock); list_for_each_entry(spidev, &device_list, device_entry) { - if (spidev->dev.devt == inode->i_rdev) { + if (spidev->devt == inode->i_rdev) { status = 0; break; } @@ -418,6 +491,7 @@ static int spidev_open(struct inode *inode, struct file *filp) pr_debug("spidev: nothing for minor %d\n", iminor(inode)); mutex_unlock(&device_list_lock); + unlock_kernel(); return status; } @@ -429,10 +503,22 @@ static int spidev_release(struct inode *inode, struct file *filp) mutex_lock(&device_list_lock); spidev = filp->private_data; filp->private_data = NULL; + + /* last close? */ spidev->users--; if (!spidev->users) { + int dofree; + kfree(spidev->buffer); spidev->buffer = NULL; + + /* ... after we unbound from the underlying device? */ + spin_lock_irq(&spidev->spi_lock); + dofree = (spidev->spi == NULL); + spin_unlock_irq(&spidev->spi_lock); + + if (dofree) + kfree(spidev); } mutex_unlock(&device_list_lock); @@ -459,19 +545,7 @@ static struct file_operations spidev_fops = { * It also simplifies memory management. */ -static void spidev_classdev_release(struct device *dev) -{ - struct spidev_data *spidev; - - spidev = container_of(dev, struct spidev_data, dev); - kfree(spidev); -} - -static struct class spidev_class = { - .name = "spidev", - .owner = THIS_MODULE, - .dev_release = spidev_classdev_release, -}; +static struct class *spidev_class; /*-------------------------------------------------------------------------*/ @@ -488,6 +562,7 @@ static int spidev_probe(struct spi_device *spi) /* Initialize the driver data */ spidev->spi = spi; + spin_lock_init(&spidev->spi_lock); mutex_init(&spidev->buf_lock); INIT_LIST_HEAD(&spidev->device_entry); @@ -498,20 +573,20 @@ static int spidev_probe(struct spi_device *spi) mutex_lock(&device_list_lock); minor = find_first_zero_bit(minors, N_SPI_MINORS); if (minor < N_SPI_MINORS) { - spidev->dev.parent = &spi->dev; - spidev->dev.class = &spidev_class; - spidev->dev.devt = MKDEV(SPIDEV_MAJOR, minor); - snprintf(spidev->dev.bus_id, sizeof spidev->dev.bus_id, + struct device *dev; + + spidev->devt = MKDEV(SPIDEV_MAJOR, minor); + dev = device_create(spidev_class, &spi->dev, spidev->devt, "spidev%d.%d", spi->master->bus_num, spi->chip_select); - status = device_register(&spidev->dev); + status = IS_ERR(dev) ? PTR_ERR(dev) : 0; } else { dev_dbg(&spi->dev, "no minor number available!\n"); status = -ENODEV; } if (status == 0) { set_bit(minor, minors); - dev_set_drvdata(&spi->dev, spidev); + spi_set_drvdata(spi, spidev); list_add(&spidev->device_entry, &device_list); } mutex_unlock(&device_list_lock); @@ -524,15 +599,21 @@ static int spidev_probe(struct spi_device *spi) static int spidev_remove(struct spi_device *spi) { - struct spidev_data *spidev = dev_get_drvdata(&spi->dev); + struct spidev_data *spidev = spi_get_drvdata(spi); - mutex_lock(&device_list_lock); + /* make sure ops on existing fds can abort cleanly */ + spin_lock_irq(&spidev->spi_lock); + spidev->spi = NULL; + spi_set_drvdata(spi, NULL); + spin_unlock_irq(&spidev->spi_lock); + /* prevent new opens */ + mutex_lock(&device_list_lock); list_del(&spidev->device_entry); - dev_set_drvdata(&spi->dev, NULL); - clear_bit(MINOR(spidev->dev.devt), minors); - device_unregister(&spidev->dev); - + 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; @@ -568,15 +649,15 @@ static int __init spidev_init(void) if (status < 0) return status; - status = class_register(&spidev_class); - if (status < 0) { + spidev_class = class_create(THIS_MODULE, "spidev"); + if (IS_ERR(spidev_class)) { unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); - return status; + return PTR_ERR(spidev_class); } status = spi_register_driver(&spidev_spi); if (status < 0) { - class_unregister(&spidev_class); + class_destroy(spidev_class); unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); } return status; @@ -586,7 +667,7 @@ module_init(spidev_init); static void __exit spidev_exit(void) { spi_unregister_driver(&spidev_spi); - class_unregister(&spidev_class); + class_destroy(spidev_class); unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); } module_exit(spidev_exit); |