From patchwork Wed Jun 8 11:23:10 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Govindraj.R" X-Patchwork-Id: 861252 X-Patchwork-Delegate: khilman@deeprootsystems.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p58I6rvB010696 for ; Wed, 8 Jun 2011 18:06:58 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753396Ab1FHLXt (ORCPT ); Wed, 8 Jun 2011 07:23:49 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:40248 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753302Ab1FHLXr (ORCPT ); Wed, 8 Jun 2011 07:23:47 -0400 Received: from dbdp20.itg.ti.com ([172.24.170.38]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id p58BNZxs023189 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 8 Jun 2011 06:23:37 -0500 Received: from dbde70.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id p58BNWY5012610; Wed, 8 Jun 2011 16:53:34 +0530 (IST) Received: from dbdp31.itg.ti.com (172.24.170.98) by DBDE70.ent.ti.com (172.24.170.148) with Microsoft SMTP Server id 8.3.106.1; Wed, 8 Jun 2011 16:53:34 +0530 Received: from localhost.localdomain (omapldc12.india.ti.com [172.24.136.100]) by dbdp31.itg.ti.com (8.13.8/8.13.8) with ESMTP id p58BNT7t028360; Wed, 8 Jun 2011 16:53:33 +0530 (IST) From: "Govindraj.R" To: , , CC: Tony Lindgren , Kevin Hilman , Jon Hunter , "Govindraj.R" Subject: [PATCH v3 08/12] Serial: OMAP2+: Make the RX_TIMEOUT for DMA configurable for each UART Date: Wed, 8 Jun 2011 16:53:10 +0530 Message-ID: <1307532194-13039-9-git-send-email-govindraj.raja@ti.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1307532194-13039-1-git-send-email-govindraj.raja@ti.com> References: <1307532194-13039-1-git-send-email-govindraj.raja@ti.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Wed, 08 Jun 2011 18:06:58 +0000 (UTC) From: Jon Hunter When using DMA there are two timeouts defined. The first timeout, rx_timeout, is really a polling rate in which software polls the DMA status to see if the DMA has finished. This is necessary for the RX side because we do not know how much data we will receive. The secound timeout, RX_TIMEOUT, is a timeout after which the DMA will be stopped if no more data is received. To make this clearer, rename rx_timeout as rx_poll_rate and rename the function serial_omap_rx_timeout() to serial_omap_rxdma_poll(). The OMAP-Serial driver defines an RX_TIMEOUT of 3 seconds that is used to indicate when the DMA for UART can be stopped if no more data is received. The value is a global definition that is applied to all instances of the UART. Each UART may be used for a different purpose and so the timeout required may differ. Make this value configurable for each UART so that this value can be optimised for power savings. Signed-off-by: Jon Hunter Signed-off-by: Govindraj.R Acked-by: Kevin Hilman --- arch/arm/mach-omap2/serial.c | 2 ++ arch/arm/plat-omap/include/plat/omap-serial.h | 6 ++++-- drivers/tty/serial/omap-serial.c | 15 ++++++++------- 3 files changed, 14 insertions(+), 9 deletions(-) diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c index f38296e..6ac078f 100644 --- a/arch/arm/mach-omap2/serial.c +++ b/arch/arm/mach-omap2/serial.c @@ -48,6 +48,7 @@ static struct omap_uart_port_info omap_serial_default_info[] = { { .dma_enabled = 0, .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE, + .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE, .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT, .auto_sus_timeout = DEFAULT_AUTOSUSPEND_DELAY, }, @@ -370,6 +371,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata, pdata->enable_wakeup = omap_uart_wakeup_enable; pdata->dma_enabled = info->dma_enabled; pdata->dma_rx_buf_size = info->dma_rx_buf_size; + pdata->dma_rx_poll_rate = info->dma_rx_poll_rate; pdata->dma_rx_timeout = info->dma_rx_timeout; pdata->auto_sus_timeout = info->auto_sus_timeout; if (bdata->id == omap_uart_con_id) diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h index 4e2dcdc..c5f4dd9 100644 --- a/arch/arm/plat-omap/include/plat/omap-serial.h +++ b/arch/arm/plat-omap/include/plat/omap-serial.h @@ -51,8 +51,8 @@ #define OMAP_UART_DMA_CH_FREE -1 -#define RX_TIMEOUT (3 * HZ) /* RX DMA timeout (jiffies) */ -#define DEFAULT_RXDMA_TIMEOUT 1 /* RX DMA polling rate (us) */ +#define DEFAULT_RXDMA_TIMEOUT (3 * HZ) /* RX DMA timeout (jiffies) */ +#define DEFAULT_RXDMA_POLLRATE 1 /* RX DMA polling rate (us) */ #define DEFAULT_RXDMA_BUFSIZE 4096 /* RX DMA buffer size */ #define DEFAULT_AUTOSUSPEND_DELAY (30 * HZ) /* Runtime autosuspend (msecs) */ @@ -71,6 +71,7 @@ struct omap_uart_port_info { unsigned int console_uart; unsigned int dma_rx_buf_size;/* DMA Rx Buffer Size */ unsigned int dma_rx_timeout; /* DMA RX timeout */ + unsigned int dma_rx_poll_rate; /* DMA RX timeout */ unsigned int auto_sus_timeout; /* Auto_suspend timeout */ void (*enable_wakeup)(struct platform_device *, bool); @@ -101,6 +102,7 @@ struct uart_omap_dma { /* timer to poll activity on rx dma */ struct timer_list rx_timer; unsigned int rx_buf_size; + unsigned int rx_poll_rate; unsigned int rx_timeout; }; diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index dc2743a..307b7c6 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -48,7 +48,7 @@ static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS]; /* Forward declaration of functions */ static void uart_tx_dma_callback(int lch, u16 ch_status, void *data); -static void serial_omap_rx_timeout(unsigned long uart_no); +static void serial_omap_rxdma_poll(unsigned long uart_no); static int serial_omap_start_rxdma(struct uart_omap_port *up); static void omap_uart_mdr1_errataset(struct uart_omap_port *up, u8 mdr1); @@ -543,7 +543,7 @@ static int serial_omap_startup(struct uart_port *port) (dma_addr_t *)&(up->uart_dma.tx_buf_dma_phys), 0); init_timer(&(up->uart_dma.rx_timer)); - up->uart_dma.rx_timer.function = serial_omap_rx_timeout; + up->uart_dma.rx_timer.function = serial_omap_rxdma_poll; up->uart_dma.rx_timer.data = up->pdev->id; /* Currently the buffer size is 4KB. Can increase it */ up->uart_dma.rx_buf = dma_alloc_coherent(NULL, @@ -1175,7 +1175,7 @@ static int serial_omap_resume(struct device *dev) return 0; } -static void serial_omap_rx_timeout(unsigned long uart_no) +static void serial_omap_rxdma_poll(unsigned long uart_no) { struct uart_omap_port *up = ui[uart_no]; unsigned int curr_dma_pos, curr_transmitted_size; @@ -1185,9 +1185,9 @@ static void serial_omap_rx_timeout(unsigned long uart_no) if ((curr_dma_pos == up->uart_dma.prev_rx_dma_pos) || (curr_dma_pos == 0)) { if (jiffies_to_msecs(jiffies - up->port_activity) < - RX_TIMEOUT) { + up->uart_dma.rx_timeout) { mod_timer(&up->uart_dma.rx_timer, jiffies + - usecs_to_jiffies(up->uart_dma.rx_timeout)); + usecs_to_jiffies(up->uart_dma.rx_poll_rate)); } else { serial_omap_stop_rxdma(up); up->ier |= (UART_IER_RDI | UART_IER_RLSI); @@ -1217,7 +1217,7 @@ static void serial_omap_rx_timeout(unsigned long uart_no) } } else { mod_timer(&up->uart_dma.rx_timer, jiffies + - usecs_to_jiffies(up->uart_dma.rx_timeout)); + usecs_to_jiffies(up->uart_dma.rx_poll_rate)); } up->port_activity = jiffies; } @@ -1259,7 +1259,7 @@ static int serial_omap_start_rxdma(struct uart_omap_port *up) /* FIXME: Cache maintenance needed here? */ omap_start_dma(up->uart_dma.rx_dma_channel); mod_timer(&up->uart_dma.rx_timer, jiffies + - usecs_to_jiffies(up->uart_dma.rx_timeout)); + usecs_to_jiffies(up->uart_dma.rx_poll_rate)); up->uart_dma.rx_dma_used = true; return ret; } @@ -1399,6 +1399,7 @@ static int serial_omap_probe(struct platform_device *pdev) up->use_dma = 1; up->uart_dma.rx_buf_size = omap_up_info->dma_rx_buf_size; up->uart_dma.rx_timeout = omap_up_info->dma_rx_timeout; + up->uart_dma.rx_poll_rate = omap_up_info->dma_rx_poll_rate; spin_lock_init(&(up->uart_dma.tx_lock)); spin_lock_init(&(up->uart_dma.rx_lock)); up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;