From a3ae0fc34f58e7163b7724feb3d77aa4603f0dc3 Mon Sep 17 00:00:00 2001 From: Jamie Iles Date: Wed, 1 Dec 2010 23:39:36 +0000 Subject: 8250: add a UPIO_DWAPB32 for 32 bit accesses Some platforms contain a Synopsys DesignWare APB UART that is attached to a 32-bit APB bus where sub-word accesses are not allowed. Add a new IO type (UPIO_DWAPB32) that performs 32 bit acccesses to the UART. v2: - don't test for 32 bit in the output fast path, provide a separate dwabp32_serial_out() function. Refactor dwabp_serial_out() so that we can reuse the LCR saving code. v3: - rebased on top of "8250: use container_of() instead of casting" Signed-off-by: Jamie Iles Signed-off-by: Greg Kroah-Hartman --- drivers/serial/8250.c | 51 +++++++++++++++++++++++++++++++++----------- drivers/serial/serial_core.c | 2 ++ 2 files changed, 41 insertions(+), 12 deletions(-) (limited to 'drivers/serial') diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 0b4ce47d987..9839199c1d1 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -454,22 +454,40 @@ static void tsi_serial_out(struct uart_port *p, int offset, int value) writeb(value, p->membase + offset); } +/* Save the LCR value so it can be re-written when a Busy Detect IRQ occurs. */ +static inline void dwapb_save_out_value(struct uart_port *p, int offset, + int value) +{ + struct uart_8250_port *up = + container_of(p, struct uart_8250_port, port); + + if (offset == UART_LCR) + up->lcr = value; +} + +/* Read the IER to ensure any interrupt is cleared before returning from ISR. */ +static inline void dwapb_check_clear_ier(struct uart_port *p, int offset) +{ + if (offset == UART_TX || offset == UART_IER) + p->serial_in(p, UART_IER); +} + static void dwapb_serial_out(struct uart_port *p, int offset, int value) { int save_offset = offset; offset = map_8250_out_reg(p, offset) << p->regshift; - /* Save the LCR value so it can be re-written when a - * Busy Detect interrupt occurs. */ - if (save_offset == UART_LCR) { - struct uart_8250_port *up = - container_of(p, struct uart_8250_port, port); - up->lcr = value; - } + dwapb_save_out_value(p, save_offset, value); writeb(value, p->membase + offset); - /* Read the IER to ensure any interrupt is cleared before - * returning from ISR. */ - if (save_offset == UART_TX || save_offset == UART_IER) - value = p->serial_in(p, UART_IER); + dwapb_check_clear_ier(p, save_offset); +} + +static void dwapb32_serial_out(struct uart_port *p, int offset, int value) +{ + int save_offset = offset; + offset = map_8250_out_reg(p, offset) << p->regshift; + dwapb_save_out_value(p, save_offset, value); + writel(value, p->membase + offset); + dwapb_check_clear_ier(p, save_offset); } static unsigned int io_serial_in(struct uart_port *p, int offset) @@ -520,6 +538,11 @@ static void set_io_from_upio(struct uart_port *p) p->serial_out = dwapb_serial_out; break; + case UPIO_DWAPB32: + p->serial_in = mem32_serial_in; + p->serial_out = dwapb32_serial_out; + break; + default: p->serial_in = io_serial_in; p->serial_out = io_serial_out; @@ -538,6 +561,7 @@ serial_out_sync(struct uart_8250_port *up, int offset, int value) case UPIO_MEM32: case UPIO_AU: case UPIO_DWAPB: + case UPIO_DWAPB32: p->serial_out(p, offset, value); p->serial_in(p, UART_LCR); /* safe, no side-effects */ break; @@ -1587,7 +1611,8 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id) handled = 1; end = NULL; - } else if (up->port.iotype == UPIO_DWAPB && + } else if ((up->port.iotype == UPIO_DWAPB || + up->port.iotype == UPIO_DWAPB32) && (iir & UART_IIR_BUSY) == UART_IIR_BUSY) { /* The DesignWare APB UART has an Busy Detect (0x07) * interrupt meaning an LCR write attempt occured while the @@ -2492,6 +2517,7 @@ static int serial8250_request_std_resource(struct uart_8250_port *up) case UPIO_MEM32: case UPIO_MEM: case UPIO_DWAPB: + case UPIO_DWAPB32: if (!up->port.mapbase) break; @@ -2529,6 +2555,7 @@ static void serial8250_release_std_resource(struct uart_8250_port *up) case UPIO_MEM32: case UPIO_MEM: case UPIO_DWAPB: + case UPIO_DWAPB32: if (!up->port.mapbase) break; diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index c4ea14670d4..2835e29298e 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -2135,6 +2135,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port) case UPIO_AU: case UPIO_TSI: case UPIO_DWAPB: + case UPIO_DWAPB32: snprintf(address, sizeof(address), "MMIO 0x%llx", (unsigned long long)port->mapbase); break; @@ -2555,6 +2556,7 @@ int uart_match_port(struct uart_port *port1, struct uart_port *port2) case UPIO_AU: case UPIO_TSI: case UPIO_DWAPB: + case UPIO_DWAPB32: return (port1->mapbase == port2->mapbase); } return 0; -- cgit v1.2.3-70-g09d2