All of lore.kernel.org
 help / color / mirror / Atom feed
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Geert Uytterhoeven <geert+renesas@glider.be>,
	Magnus Damm <magnus.damm@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	linux-renesas-soc@vger.kernel.org, linux-serial@vger.kernel.org,
	Milan Stevanovic <milan.stevanovic@se.com>,
	Jimmy Lalande <jimmy.lalande@se.com>,
	Pascal Eberhard <pascal.eberhard@se.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Herve Codina <herve.codina@bootlin.com>,
	Clement Leger <clement.leger@bootlin.com>,
	Ilpo Jarvinen <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH v6 05/12] serial: 8250: dma: Allow driver operations before starting DMA transfers
Date: Thu, 21 Apr 2022 11:53:16 +0200	[thread overview]
Message-ID: <20220421095323.101811-6-miquel.raynal@bootlin.com> (raw)
In-Reply-To: <20220421095323.101811-1-miquel.raynal@bootlin.com>

One situation where this could be used is when configuring the UART
controller to be the DMA flow controller. This is a typical case where
the driver might need to program a few more registers before starting a
DMA transfer. Provide the necessary infrastructure to support this
case.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250.h     | 18 ++++++++++++++++++
 drivers/tty/serial/8250/8250_dma.c |  4 ++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 39ffeb37786f..5a4e05c0e552 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -17,6 +17,8 @@
 struct uart_8250_dma {
 	int (*tx_dma)(struct uart_8250_port *p);
 	int (*rx_dma)(struct uart_8250_port *p);
+	void (*prepare_tx_dma)(struct uart_8250_port *p);
+	void (*prepare_rx_dma)(struct uart_8250_port *p);
 
 	/* Filter function */
 	dma_filter_fn		fn;
@@ -302,6 +304,22 @@ extern int serial8250_rx_dma(struct uart_8250_port *);
 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
 extern int serial8250_request_dma(struct uart_8250_port *);
 extern void serial8250_release_dma(struct uart_8250_port *);
+
+static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma *dma = p->dma;
+
+	if (dma->prepare_tx_dma)
+		dma->prepare_tx_dma(p);
+}
+
+static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma *dma = p->dma;
+
+	if (dma->prepare_rx_dma)
+		dma->prepare_rx_dma(p);
+}
 #else
 static inline int serial8250_tx_dma(struct uart_8250_port *p)
 {
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index b3c3f7e5851a..1bdc8d6432fe 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -86,6 +86,8 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 
 	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
 
+	serial8250_do_prepare_tx_dma(p);
+
 	desc = dmaengine_prep_slave_single(dma->txchan,
 					   dma->tx_addr + xmit->tail,
 					   dma->tx_size, DMA_MEM_TO_DEV,
@@ -123,6 +125,8 @@ int serial8250_rx_dma(struct uart_8250_port *p)
 	if (dma->rx_running)
 		return 0;
 
+	serial8250_do_prepare_rx_dma(p);
+
 	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
 					   dma->rx_size, DMA_DEV_TO_MEM,
 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-- 
2.27.0


  parent reply	other threads:[~2022-04-21  9:53 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-21  9:53 [PATCH v6 00/12] serial: 8250: dw: RZN1 DMA support Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 01/12] serial: 8250: dw: Move definitions to the shared header Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 02/12] serial: 8250: dw: Create a generic platform data structure Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 03/12] serial: 8250: dw: Move the USR register to pdata Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 04/12] serial: 8250: dw: Allow to use a fallback CPR value if not synthesized Miquel Raynal
2022-04-21  9:53 ` Miquel Raynal [this message]
2022-04-21  9:53 ` [PATCH v6 06/12] serial: 8250: dw: Introduce an rx_timeout variable in the IRQ path Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 07/12] serial: 8250: dw: Move the IO accessors to 8250_dwlib.h Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 08/12] serial: 8250: dw: Add support for DMA flow controlling devices Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 09/12] serial: 8250: dw: Improve RZN1 support Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 10/12] ARM: dts: r9a06g032: Fill the UART DMA properties Miquel Raynal
2022-04-28  9:09   ` Geert Uytterhoeven
2022-05-03  8:36     ` Geert Uytterhoeven
2022-04-21  9:53 ` [PATCH v6 11/12] bestla: Enable DMA, UART3 and UART4 Miquel Raynal
2022-04-21 10:21   ` Miquel Raynal
2022-04-22 14:04     ` Greg Kroah-Hartman
2022-04-22 14:26       ` Geert Uytterhoeven
2022-04-22 15:52         ` Miquel Raynal
2022-04-21  9:53 ` [PATCH v6 12/12] bestla: Add support for RZN1 dmamux Miquel Raynal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220421095323.101811-6-miquel.raynal@bootlin.com \
    --to=miquel.raynal@bootlin.com \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=clement.leger@bootlin.com \
    --cc=geert+renesas@glider.be \
    --cc=gregkh@linuxfoundation.org \
    --cc=herve.codina@bootlin.com \
    --cc=ilpo.jarvinen@linux.intel.com \
    --cc=jimmy.lalande@se.com \
    --cc=jirislaby@kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=magnus.damm@gmail.com \
    --cc=milan.stevanovic@se.com \
    --cc=pascal.eberhard@se.com \
    --cc=thomas.petazzoni@bootlin.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.