diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_omap.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_omap.c | 48 |
1 files changed, 42 insertions, 6 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 562087df7d33..23e0decde33e 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -27,6 +27,7 @@ #include <linux/pm_qos.h> #include <linux/pm_wakeirq.h> #include <linux/dma-mapping.h> +#include <linux/sys_soc.h> #include "8250.h" @@ -41,6 +42,7 @@ */ #define UART_ERRATA_CLOCK_DISABLE (1 << 3) #define UART_HAS_EFR2 BIT(4) +#define UART_HAS_RHR_IT_DIS BIT(5) #define OMAP_UART_FCR_RX_TRIG 6 #define OMAP_UART_FCR_TX_TRIG 4 @@ -94,6 +96,10 @@ #define OMAP_UART_REV_52 0x0502 #define OMAP_UART_REV_63 0x0603 +/* Interrupt Enable Register 2 */ +#define UART_OMAP_IER2 0x1B +#define UART_OMAP_IER2_RHR_IT_DIS BIT(2) + /* Enhanced features register 2 */ #define UART_OMAP_EFR2 0x23 #define UART_OMAP_EFR2_TIMEOUT_BEHAVE BIT(6) @@ -184,11 +190,6 @@ static void omap_8250_mdr1_errataset(struct uart_8250_port *up, struct omap8250_priv *priv) { u8 timeout = 255; - u8 old_mdr1; - - old_mdr1 = serial_in(up, UART_OMAP_MDR1); - if (old_mdr1 == priv->mdr1) - return; serial_out(up, UART_OMAP_MDR1, priv->mdr1); udelay(2); @@ -533,6 +534,11 @@ static void omap_8250_pm(struct uart_port *port, unsigned int state, static void omap_serial_fill_features_erratas(struct uart_8250_port *up, struct omap8250_priv *priv) { + const struct soc_device_attribute k3_soc_devices[] = { + { .family = "AM65X", }, + { .family = "J721E", .revision = "SR1.0" }, + { /* sentinel */ } + }; u32 mvr, scheme; u16 revision, major, minor; @@ -580,6 +586,14 @@ static void omap_serial_fill_features_erratas(struct uart_8250_port *up, default: break; } + + /* + * AM65x SR1.0, AM65x SR2.0 and J721e SR1.0 don't + * don't have RHR_IT_DIS bit in IER2 register. So drop to flag + * to enable errata workaround. + */ + if (soc_device_match(k3_soc_devices)) + priv->habit &= ~UART_HAS_RHR_IT_DIS; } static void omap8250_uart_qos_work(struct work_struct *work) @@ -761,17 +775,27 @@ static void __dma_rx_do_complete(struct uart_8250_port *p) { struct uart_8250_dma *dma = p->dma; struct tty_port *tty_port = &p->port.state->port; + struct omap8250_priv *priv = p->port.private_data; struct dma_chan *rxchan = dma->rxchan; dma_cookie_t cookie; struct dma_tx_state state; int count; int ret; + u32 reg; if (!dma->rx_running) goto out; cookie = dma->rx_cookie; dma->rx_running = 0; + + /* Re-enable RX FIFO interrupt now that transfer is complete */ + if (priv->habit & UART_HAS_RHR_IT_DIS) { + reg = serial_in(p, UART_OMAP_IER2); + reg &= ~UART_OMAP_IER2_RHR_IT_DIS; + serial_out(p, UART_OMAP_IER2, UART_OMAP_IER2_RHR_IT_DIS); + } + dmaengine_tx_status(rxchan, cookie, &state); count = dma->rx_size - state.residue + state.in_flight_bytes; @@ -867,6 +891,7 @@ static int omap_8250_rx_dma(struct uart_8250_port *p) int err = 0; struct dma_async_tx_descriptor *desc; unsigned long flags; + u32 reg; if (priv->rx_dma_broken) return -EINVAL; @@ -902,6 +927,17 @@ static int omap_8250_rx_dma(struct uart_8250_port *p) dma->rx_cookie = dmaengine_submit(desc); + /* + * Disable RX FIFO interrupt while RX DMA is enabled, else + * spurious interrupt may be raised when data is in the RX FIFO + * but is yet to be drained by DMA. + */ + if (priv->habit & UART_HAS_RHR_IT_DIS) { + reg = serial_in(p, UART_OMAP_IER2); + reg |= UART_OMAP_IER2_RHR_IT_DIS; + serial_out(p, UART_OMAP_IER2, UART_OMAP_IER2_RHR_IT_DIS); + } + dma_async_issue_pending(dma->rxchan); out: spin_unlock_irqrestore(&priv->rx_dma_lock, flags); @@ -1182,7 +1218,7 @@ static struct omap8250_dma_params am33xx_dma = { static struct omap8250_platdata am654_platdata = { .dma_params = &am654_dma, - .habit = UART_HAS_EFR2, + .habit = UART_HAS_EFR2 | UART_HAS_RHR_IT_DIS, }; static struct omap8250_platdata am33xx_platdata = { |