/* Revisit: We should calculate this based on the actual port settings */
#define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
+/* The minium number of data FIFOs should be able to contain */
+#define ATMEL_MIN_FIFO_SIZE 8
+/*
+ * These two offsets are substracted from the RX FIFO size to define the RTS
+ * high and low thresholds
+ */
+#define ATMEL_RTS_HIGH_OFFSET 16
+#define ATMEL_RTS_LOW_OFFSET 20
+
#if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
struct mctrl_gpios *gpios;
int gpio_irq[UART_GPIO_MAX];
unsigned int tx_done_mask;
+ u32 fifo_size;
+ u32 rts_high;
+ u32 rts_low;
bool ms_irq_enabled;
bool is_usart; /* usart or uart */
struct timer_list uart_timer; /* uart timer */
__raw_writel(value, port->membase + reg);
}
+static inline u8 atmel_uart_readb(struct uart_port *port, u32 reg)
+{
+ return __raw_readb(port->membase + reg);
+}
+
+static inline void atmel_uart_writeb(struct uart_port *port, u32 reg, u8 value)
+{
+ __raw_writeb(value, port->membase + reg);
+}
+
#ifdef CONFIG_SERIAL_ATMEL_PDC
static bool atmel_use_pdc_rx(struct uart_port *port)
{
status = atmel_uart_readl(port, ATMEL_US_CSR);
while (status & ATMEL_US_RXRDY) {
- ch = atmel_uart_readl(port, ATMEL_US_RHR);
+ ch = atmel_uart_readb(port, ATMEL_US_RHR);
/*
* note that the error handling code is
if (port->x_char &&
(atmel_uart_readl(port, ATMEL_US_CSR) & atmel_port->tx_done_mask)) {
- atmel_uart_writel(port, ATMEL_US_THR, port->x_char);
+ atmel_uart_writeb(port, ATMEL_US_THR, port->x_char);
port->icount.tx++;
port->x_char = 0;
}
while (atmel_uart_readl(port, ATMEL_US_CSR) &
atmel_port->tx_done_mask) {
- atmel_uart_writel(port, ATMEL_US_THR, xmit->buf[xmit->tail]);
+ atmel_uart_writeb(port, ATMEL_US_THR, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_empty(xmit))
atmel_set_ops(port);
}
+ /*
+ * Enable FIFO when available
+ */
+ if (atmel_port->fifo_size) {
+ unsigned int txrdym = ATMEL_US_ONE_DATA;
+ unsigned int rxrdym = ATMEL_US_ONE_DATA;
+ unsigned int fmr;
+
+ atmel_uart_writel(port, ATMEL_US_CR,
+ ATMEL_US_FIFOEN |
+ ATMEL_US_RXFCLR |
+ ATMEL_US_TXFLCLR);
+
+ fmr = ATMEL_US_TXRDYM(txrdym) | ATMEL_US_RXRDYM(rxrdym);
+ if (atmel_port->rts_high &&
+ atmel_port->rts_low)
+ fmr |= ATMEL_US_FRTSC |
+ ATMEL_US_RXFTHRES(atmel_port->rts_high) |
+ ATMEL_US_RXFTHRES2(atmel_port->rts_low);
+
+ atmel_uart_writel(port, ATMEL_US_FMR, fmr);
+ }
+
/* Save current CSR for comparison in atmel_tasklet_func() */
atmel_port->irq_status_prev = atmel_get_lines_status(port);
atmel_port->irq_status = atmel_port->irq_status_prev;
while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_RXRDY))
cpu_relax();
- return atmel_uart_readl(port, ATMEL_US_RHR);
+ return atmel_uart_readb(port, ATMEL_US_RHR);
}
static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY))
cpu_relax();
- atmel_uart_writel(port, ATMEL_US_THR, ch);
+ atmel_uart_writeb(port, ATMEL_US_THR, ch);
}
#endif
{
while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY))
cpu_relax();
- atmel_uart_writel(port, ATMEL_US_THR, ch);
+ atmel_uart_writeb(port, ATMEL_US_THR, ch);
}
/*
return 0;
}
+static void atmel_serial_probe_fifos(struct atmel_uart_port *port,
+ struct platform_device *pdev)
+{
+ port->fifo_size = 0;
+ port->rts_low = 0;
+ port->rts_high = 0;
+
+ if (of_property_read_u32(pdev->dev.of_node,
+ "atmel,fifo-size",
+ &port->fifo_size))
+ return;
+
+ if (!port->fifo_size)
+ return;
+
+ if (port->fifo_size < ATMEL_MIN_FIFO_SIZE) {
+ port->fifo_size = 0;
+ dev_err(&pdev->dev, "Invalid FIFO size\n");
+ return;
+ }
+
+ /*
+ * 0 <= rts_low <= rts_high <= fifo_size
+ * Once their CTS line asserted by the remote peer, some x86 UARTs tend
+ * to flush their internal TX FIFO, commonly up to 16 data, before
+ * actually stopping to send new data. So we try to set the RTS High
+ * Threshold to a reasonably high value respecting this 16 data
+ * empirical rule when possible.
+ */
+ port->rts_high = max_t(int, port->fifo_size >> 1,
+ port->fifo_size - ATMEL_RTS_HIGH_OFFSET);
+ port->rts_low = max_t(int, port->fifo_size >> 2,
+ port->fifo_size - ATMEL_RTS_LOW_OFFSET);
+
+ dev_info(&pdev->dev, "Using FIFO (%u data)\n",
+ port->fifo_size);
+ dev_dbg(&pdev->dev, "RTS High Threshold : %2u data\n",
+ port->rts_high);
+ dev_dbg(&pdev->dev, "RTS Low Threshold : %2u data\n",
+ port->rts_low);
+}
+
static int atmel_serial_probe(struct platform_device *pdev)
{
struct atmel_uart_port *port;
port = &atmel_ports[ret];
port->backup_imr = 0;
port->uart.line = ret;
+ atmel_serial_probe_fifos(port, pdev);
spin_lock_init(&port->lock_suspended);
#define ATMEL_US_DTRDIS BIT(17) /* Data Terminal Ready Disable */
#define ATMEL_US_RTSEN BIT(18) /* Request To Send Enable */
#define ATMEL_US_RTSDIS BIT(19) /* Request To Send Disable */
+#define ATMEL_US_TXFCLR BIT(24) /* Transmit FIFO Clear */
+#define ATMEL_US_RXFCLR BIT(25) /* Receive FIFO Clear */
+#define ATMEL_US_TXFLCLR BIT(26) /* Transmit FIFO Lock Clear */
+#define ATMEL_US_FIFOEN BIT(30) /* FIFO enable */
+#define ATMEL_US_FIFODIS BIT(31) /* FIFO disable */
#define ATMEL_US_MR 0x04 /* Mode Register */
#define ATMEL_US_USMODE GENMASK(3, 0) /* Mode of the USART */
#define ATMEL_US_NER 0x44 /* Number of Errors Register */
#define ATMEL_US_IF 0x4c /* IrDA Filter Register */
+#define ATMEL_US_CMPR 0x90 /* Comparaison Register */
+#define ATMEL_US_FMR 0xa0 /* FIFO Mode Register */
+#define ATMEL_US_TXRDYM(data) (((data) & 0x3) << 0) /* TX Ready Mode */
+#define ATMEL_US_RXRDYM(data) (((data) & 0x3) << 4) /* RX Ready Mode */
+#define ATMEL_US_ONE_DATA 0x0
+#define ATMEL_US_TWO_DATA 0x1
+#define ATMEL_US_FOUR_DATA 0x2
+#define ATMEL_US_FRTSC BIT(7) /* FIFO RTS pin Control */
+#define ATMEL_US_TXFTHRES(thr) (((thr) & 0x3f) << 8) /* TX FIFO Threshold */
+#define ATMEL_US_RXFTHRES(thr) (((thr) & 0x3f) << 16) /* RX FIFO Threshold */
+#define ATMEL_US_RXFTHRES2(thr) (((thr) & 0x3f) << 24) /* RX FIFO Threshold2 */
+
+#define ATMEL_US_FLR 0xa4 /* FIFO Level Register */
+#define ATMEL_US_TXFL(reg) (((reg) >> 0) & 0x3f) /* TX FIFO Level */
+#define ATMEL_US_RXFL(reg) (((reg) >> 16) & 0x3f) /* RX FIFO Level */
+
+#define ATMEL_US_FIER 0xa8 /* FIFO Interrupt Enable Register */
+#define ATMEL_US_FIDR 0xac /* FIFO Interrupt Disable Register */
+#define ATMEL_US_FIMR 0xb0 /* FIFO Interrupt Mask Register */
+#define ATMEL_US_FESR 0xb4 /* FIFO Event Status Register */
+#define ATMEL_US_TXFEF BIT(0) /* Transmit FIFO Empty Flag */
+#define ATMEL_US_TXFFF BIT(1) /* Transmit FIFO Full Flag */
+#define ATMEL_US_TXFTHF BIT(2) /* Transmit FIFO Threshold Flag */
+#define ATMEL_US_RXFEF BIT(3) /* Receive FIFO Empty Flag */
+#define ATMEL_US_RXFFF BIT(4) /* Receive FIFO Full Flag */
+#define ATMEL_US_RXFTHF BIT(5) /* Receive FIFO Threshold Flag */
+#define ATMEL_US_TXFPTEF BIT(6) /* Transmit FIFO Pointer Error Flag */
+#define ATMEL_US_RXFPTEF BIT(7) /* Receive FIFO Pointer Error Flag */
+#define ATMEL_US_TXFLOCK BIT(8) /* Transmit FIFO Lock (FESR only) */
+#define ATMEL_US_RXFTHF2 BIT(9) /* Receive FIFO Threshold Flag 2 */
+
#define ATMEL_US_NAME 0xf0 /* Ip Name */
#define ATMEL_US_VERSION 0xfc /* Ip Version */
projects / deliverable / linux.git / commitdiff
