diff options
Diffstat (limited to 'package/ucmb/src/ucmb.c')
| -rw-r--r-- | package/ucmb/src/ucmb.c | 109 |
1 files changed, 101 insertions, 8 deletions
diff --git a/package/ucmb/src/ucmb.c b/package/ucmb/src/ucmb.c index 4807f95ce3..c2cb1a9c6c 100644 --- a/package/ucmb/src/ucmb.c +++ b/package/ucmb/src/ucmb.c @@ -16,6 +16,7 @@ #include <linux/spi/spi_gpio.h> #include <linux/spi/spi_bitbang.h> #include <linux/gfp.h> +#include <linux/delay.h> #define PFX "ucmb: " @@ -39,12 +40,34 @@ struct ucmb { struct platform_device spi_gpio_pdev; }; +struct ucmb_message_hdr { + __le16 magic; /* UCMB_MAGIC */ + __le16 len; /* Payload length (excluding header) */ +} __attribute__((packed)); + +struct ucmb_status { + __le16 magic; /* UCMB_MAGIC */ + __le16 code; /* enum ucmb_status_code */ +} __attribute__((packed)); + +#define UCMB_MAGIC 0x1337 +#define UCMB_MAX_MSG_LEN 0x200 + +enum ucmb_status_code { + UCMB_STAT_OK = 0, + UCMB_STAT_EPROTO, /* Protocol format error */ + UCMB_STAT_ENOMEM, /* Out of memory */ + UCMB_STAT_E2BIG, /* Message too big */ +}; + + static int ucmb_spi_busnum_count = 1337; static struct ucmb_platform_data ucmb_list[] = { { //FIXME don't define it here. .name = "ucmb", + .gpio_cs = 3, .gpio_sck = 0, .gpio_miso = 1, .gpio_mosi = 2, @@ -72,6 +95,21 @@ static struct spi_driver ucmb_spi_driver = { .remove = __devexit_p(ucmb_spi_remove), }; +static int ucmb_status_code_to_errno(enum ucmb_status_code code) +{ + switch (code) { + case UCMB_STAT_OK: + return 0; + case UCMB_STAT_EPROTO: + return -EPROTO; + case UCMB_STAT_ENOMEM: + return -ENOMEM; + case UCMB_STAT_E2BIG: + return -E2BIG; + } + return -EBUSY; +} + static inline struct ucmb * filp_to_ucmb(struct file *filp) { return container_of(filp->f_op, struct ucmb, mdev_fops); @@ -83,29 +121,48 @@ static ssize_t ucmb_read(struct file *filp, char __user *user_buf, { struct ucmb *ucmb = filp_to_ucmb(filp); u8 *buf; - int err; + int res, err; + struct ucmb_message_hdr hdr; + struct ucmb_status status = { .magic = cpu_to_le16(UCMB_MAGIC), }; err = -E2BIG; if (size > PAGE_SIZE) goto out; + if (size > UCMB_MAX_MSG_LEN) + goto out; err = -ENOMEM; buf = (char *)__get_free_page(GFP_KERNEL); if (!buf) goto out; + err = spi_read(ucmb->sdev, (u8 *)&hdr, sizeof(hdr)); + if (err) + goto out_free; + err = -EPROTO; + if (hdr.magic != cpu_to_le16(UCMB_MAGIC)) + goto out_free; + err = -ENOBUFS; + if (size < le16_to_cpu(hdr.len)) + goto out_free; + size = le16_to_cpu(hdr.len); err = spi_read(ucmb->sdev, buf, size); if (err) goto out_free; err = -EFAULT; if (copy_to_user(user_buf, buf, size)) - goto out_free; + goto out_send_status; err = 0; +out_send_status: + status.code = err ? UCMB_STAT_ENOMEM : UCMB_STAT_OK; + res = spi_write(ucmb->sdev, (u8 *)&status, sizeof(status)); + if (res && !err) + err = res; out_free: - __free_page((unsigned long)buf); + free_page((unsigned long)buf); out: return err ? err : size; } @@ -117,21 +174,57 @@ static ssize_t ucmb_write(struct file *filp, const char __user *user_buf, struct ucmb *ucmb = filp_to_ucmb(filp); u8 *buf; int err; + struct ucmb_message_hdr hdr = { .magic = cpu_to_le16(UCMB_MAGIC), }; + struct ucmb_status status; + struct spi_transfer spi_hdr_xfer; + struct spi_transfer spi_data_xfer; + struct spi_message spi_msg; err = -ENOMEM; buf = (char *)__get_free_page(GFP_KERNEL); if (!buf) goto out; - size = min(PAGE_SIZE, size); + size = min_t(size_t, PAGE_SIZE, size); + size = min_t(size_t, UCMB_MAX_MSG_LEN, size); err = -EFAULT; if (copy_from_user(buf, user_buf, size)) goto out_free; + hdr.len = cpu_to_le16(size); + + spi_message_init(&spi_msg); - err = spi_write(ucmb->sdev, buf, size); + memset(&spi_hdr_xfer, 0, sizeof(spi_hdr_xfer)); + spi_hdr_xfer.tx_buf = &hdr; + spi_hdr_xfer.len = sizeof(hdr); + spi_message_add_tail(&spi_hdr_xfer, &spi_msg); + + memset(&spi_data_xfer, 0, sizeof(spi_data_xfer)); + spi_data_xfer.tx_buf = buf; + spi_data_xfer.len = size; + spi_message_add_tail(&spi_data_xfer, &spi_msg); + + /* Send the message, including header. */ + err = spi_sync(ucmb->sdev, &spi_msg); + if (err) + goto out_free; + + /* The microcontroller deserves some time to process the message. */ + msleep(1); + + /* Get the status code. */ + err = spi_read(ucmb->sdev, (u8 *)&status, sizeof(status)); + if (err) + goto out_free; + err = -EPROTO; + if (status.magic != cpu_to_le16(UCMB_MAGIC)) + goto out_free; + err = ucmb_status_code_to_errno(le16_to_cpu(status.code)); + if (err) + goto out_free; out_free: - __free_page((unsigned long)buf); + free_page((unsigned long)buf); out: return err ? err : size; } @@ -187,12 +280,12 @@ static int __devinit ucmb_probe(struct platform_device *pdev) printk(KERN_ERR PFX "Failed to allocate SPI device\n"); goto err_unreg_spi_gpio_pdev; } - ucmb->sdev->max_speed_hz = 5000000; + ucmb->sdev->max_speed_hz = 500000; ucmb->sdev->chip_select = 0; ucmb->sdev->mode = SPI_MODE_0; strlcpy(ucmb->sdev->modalias, "ucmb", /* We are the SPI driver. */ sizeof(ucmb->sdev->modalias)); - ucmb->sdev->controller_data = (void *)SPI_GPIO_NO_CHIPSELECT; + ucmb->sdev->controller_data = (void *)pdata->gpio_cs; err = spi_add_device(ucmb->sdev); if (err) { printk(KERN_ERR PFX "Failed to add SPI device\n"); |