diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_dw.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 68 |
1 files changed, 39 insertions, 29 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index bb6aca07ab56..a604b42e4458 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -9,26 +9,27 @@ * LCR is written whilst busy. If it is, then a busy detect interrupt is * raised, the LCR needs to be rewritten and the uart status register read. */ +#include <linux/acpi.h> +#include <linux/clk.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/io.h> #include <linux/mod_devicetable.h> #include <linux/module.h> -#include <linux/serial_8250.h> -#include <linux/serial_reg.h> +#include <linux/notifier.h> #include <linux/of.h> #include <linux/platform_device.h> +#include <linux/pm_runtime.h> #include <linux/property.h> -#include <linux/workqueue.h> -#include <linux/notifier.h> -#include <linux/slab.h> -#include <linux/acpi.h> -#include <linux/clk.h> #include <linux/reset.h> -#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/workqueue.h> #include <asm/byteorder.h> +#include <linux/serial_8250.h> +#include <linux/serial_reg.h> + #include "8250_dwlib.h" /* Offsets for the DesignWare specific registers */ @@ -82,8 +83,21 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value) static void dw8250_force_idle(struct uart_port *p) { struct uart_8250_port *up = up_to_u8250p(p); + unsigned int lsr; serial8250_clear_and_reinit_fifos(up); + + /* + * With PSLVERR_RESP_EN parameter set to 1, the device generates an + * error response when an attempt to read an empty RBR with FIFO + * enabled. + */ + if (up->fcr & UART_FCR_ENABLE_FIFO) { + lsr = p->serial_in(p, UART_LSR); + if (!(lsr & UART_LSR_DR)) + return; + } + (void)p->serial_in(p, UART_RX); } @@ -122,12 +136,15 @@ static void dw8250_check_lcr(struct uart_port *p, int value) /* Returns once the transmitter is empty or we run out of retries */ static void dw8250_tx_wait_empty(struct uart_port *p) { + struct uart_8250_port *up = up_to_u8250p(p); unsigned int tries = 20000; unsigned int delay_threshold = tries - 1000; unsigned int lsr; while (tries--) { lsr = readb (p->membase + (UART_LSR << p->regshift)); + up->lsr_saved_flags |= lsr & up->lsr_save_mask; + if (lsr & UART_LSR_TEMT) break; @@ -140,29 +157,23 @@ static void dw8250_tx_wait_empty(struct uart_port *p) } } -static void dw8250_serial_out38x(struct uart_port *p, int offset, int value) +static void dw8250_serial_out(struct uart_port *p, int offset, int value) { struct dw8250_data *d = to_dw8250_data(p->private_data); - /* Allow the TX to drain before we reconfigure */ - if (offset == UART_LCR) - dw8250_tx_wait_empty(p); - writeb(value, p->membase + (offset << p->regshift)); if (offset == UART_LCR && !d->uart_16550_compatible) dw8250_check_lcr(p, value); } - -static void dw8250_serial_out(struct uart_port *p, int offset, int value) +static void dw8250_serial_out38x(struct uart_port *p, int offset, int value) { - struct dw8250_data *d = to_dw8250_data(p->private_data); - - writeb(value, p->membase + (offset << p->regshift)); + /* Allow the TX to drain before we reconfigure */ + if (offset == UART_LCR) + dw8250_tx_wait_empty(p); - if (offset == UART_LCR && !d->uart_16550_compatible) - dw8250_check_lcr(p, value); + dw8250_serial_out(p, offset, value); } static unsigned int dw8250_serial_in(struct uart_port *p, int offset) @@ -253,7 +264,7 @@ static int dw8250_handle_irq(struct uart_port *p) */ if (!up->dma && rx_timeout) { spin_lock_irqsave(&p->lock, flags); - status = p->serial_in(p, UART_LSR); + status = serial_lsr_in(up); if (!(status & (UART_LSR_DR | UART_LSR_BI))) (void) p->serial_in(p, UART_RX); @@ -263,7 +274,10 @@ static int dw8250_handle_irq(struct uart_port *p) /* Manually stop the Rx DMA transfer when acting as flow controller */ if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) { - status = p->serial_in(p, UART_LSR); + spin_lock_irqsave(&p->lock, flags); + status = serial_lsr_in(up); + spin_unlock_irqrestore(&p->lock, flags); + if (status & (UART_LSR_DR | UART_LSR_BI)) { dw8250_writel_ext(p, RZN1_UART_RDMACR, 0); dw8250_writel_ext(p, DW_UART_DMASA, 1); @@ -688,7 +702,6 @@ static int dw8250_remove(struct platform_device *pdev) return 0; } -#ifdef CONFIG_PM_SLEEP static int dw8250_suspend(struct device *dev) { struct dw8250_data *data = dev_get_drvdata(dev); @@ -706,9 +719,7 @@ static int dw8250_resume(struct device *dev) return 0; } -#endif /* CONFIG_PM_SLEEP */ -#ifdef CONFIG_PM static int dw8250_runtime_suspend(struct device *dev) { struct dw8250_data *data = dev_get_drvdata(dev); @@ -730,11 +741,10 @@ static int dw8250_runtime_resume(struct device *dev) return 0; } -#endif static const struct dev_pm_ops dw8250_pm_ops = { - SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume) - SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL) + SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume) + RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL) }; static const struct dw8250_platform_data dw8250_dw_apb = { @@ -792,7 +802,7 @@ MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match); static struct platform_driver dw8250_platform_driver = { .driver = { .name = "dw-apb-uart", - .pm = &dw8250_pm_ops, + .pm = pm_ptr(&dw8250_pm_ops), .of_match_table = dw8250_of_match, .acpi_match_table = dw8250_acpi_match, }, |