diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 57 |
1 files changed, 53 insertions, 4 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index d96e02e25be4..e104092f7d51 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -25,6 +25,28 @@ #include <linux/platform_device.h> #include <linux/slab.h> +/* Offsets for the DesignWare specific registers */ +#define DW_UART_USR 0x1f /* UART Status Register */ +#define DW_UART_CPR 0xf4 /* Component Parameter Register */ +#define DW_UART_UCV 0xf8 /* UART Component Version */ + +/* Component Parameter Register bits */ +#define DW_UART_CPR_ABP_DATA_WIDTH (3 << 0) +#define DW_UART_CPR_AFCE_MODE (1 << 4) +#define DW_UART_CPR_THRE_MODE (1 << 5) +#define DW_UART_CPR_SIR_MODE (1 << 6) +#define DW_UART_CPR_SIR_LP_MODE (1 << 7) +#define DW_UART_CPR_ADDITIONAL_FEATURES (1 << 8) +#define DW_UART_CPR_FIFO_ACCESS (1 << 9) +#define DW_UART_CPR_FIFO_STAT (1 << 10) +#define DW_UART_CPR_SHADOW (1 << 11) +#define DW_UART_CPR_ENCODED_PARMS (1 << 12) +#define DW_UART_CPR_DMA_EXTRA (1 << 13) +#define DW_UART_CPR_FIFO_MODE (0xff << 16) +/* Helper for fifo size calculation */ +#define DW_UART_CPR_FIFO_SIZE(a) (((a >> 16) & 0xff) * 16) + + struct dw8250_data { int last_lcr; int line; @@ -66,9 +88,6 @@ static unsigned int dw8250_serial_in32(struct uart_port *p, int offset) return readl(p->membase + offset); } -/* Offset for the DesignWare's UART Status Register. */ -#define UART_USR 0x1f - static int dw8250_handle_irq(struct uart_port *p) { struct dw8250_data *d = p->private_data; @@ -78,7 +97,7 @@ static int dw8250_handle_irq(struct uart_port *p) return 1; } else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) { /* Clear the USR and write the LCR again. */ - (void)p->serial_in(p, UART_USR); + (void)p->serial_in(p, DW_UART_USR); p->serial_out(p, d->last_lcr, UART_LCR); return 1; @@ -119,6 +138,34 @@ static int dw8250_probe_of(struct uart_port *p) return 0; } +static void dw8250_setup_port(struct uart_8250_port *up) +{ + struct uart_port *p = &up->port; + u32 reg = readl(p->membase + DW_UART_UCV); + + /* + * If the Component Version Register returns zero, we know that + * ADDITIONAL_FEATURES are not enabled. No need to go any further. + */ + if (!reg) + return; + + dev_dbg_ratelimited(p->dev, "Designware UART version %c.%c%c\n", + (reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff); + + reg = readl(p->membase + DW_UART_CPR); + if (!reg) + return; + + /* Select the type based on fifo */ + if (reg & DW_UART_CPR_FIFO_MODE) { + p->type = PORT_16550A; + p->flags |= UPF_FIXED_TYPE; + p->fifosize = DW_UART_CPR_FIFO_SIZE(reg); + up->tx_loadsz = p->fifosize; + } +} + static int dw8250_probe(struct platform_device *pdev) { struct uart_8250_port uart = {}; @@ -156,6 +203,8 @@ static int dw8250_probe(struct platform_device *pdev) return -ENODEV; } + dw8250_setup_port(&uart); + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; |