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From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Vinod Koul <vkoul@kernel.org>, Viresh Kumar <vireshk@kernel.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Dan Williams <dan.j.williams@intel.com>
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>,
	Serge Semin <fancer.lancer@gmail.com>,
	Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
	Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
	Peter Ujfalusi <peter.ujfalusi@ti.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Rob Herring <robh+dt@kernel.org>, <dmaengine@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v8 03/10] dmaengine: Introduce min burst length capability
Date: Thu, 23 Jul 2020 03:58:41 +0300
Message-ID: <20200723005848.31907-4-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20200723005848.31907-1-Sergey.Semin@baikalelectronics.ru>

Some hardware aside from default 0/1 may have greater minimum burst
transactions length constraints. Here we introduce the DMA device
and slave capability, which if required can be initialized by the DMA
engine driver with the device-specific value.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

---

Changelog v3:
- This is a new patch created as a result of the discussion with Vinud and
  Andy in the framework of DW DMA burst and LLP capabilities.
---
 drivers/dma/dmaengine.c   | 1 +
 include/linux/dmaengine.h | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 2b06a7a8629d..2f1a7c0c5446 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -592,6 +592,7 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
 	caps->src_addr_widths = device->src_addr_widths;
 	caps->dst_addr_widths = device->dst_addr_widths;
 	caps->directions = device->directions;
+	caps->min_burst = device->min_burst;
 	caps->max_burst = device->max_burst;
 	caps->residue_granularity = device->residue_granularity;
 	caps->descriptor_reuse = device->descriptor_reuse;
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 6283917edd90..669833c15dfc 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -465,6 +465,7 @@ enum dma_residue_granularity {
  *	Since the enum dma_transfer_direction is not defined as bit flag for
  *	each type, the dma controller should set BIT(<TYPE>) and same
  *	should be checked by controller as well
+ * @min_burst: min burst capability per-transfer
  * @max_burst: max burst capability per-transfer
  * @cmd_pause: true, if pause is supported (i.e. for reading residue or
  *	       for resume later)
@@ -478,6 +479,7 @@ struct dma_slave_caps {
 	u32 src_addr_widths;
 	u32 dst_addr_widths;
 	u32 directions;
+	u32 min_burst;
 	u32 max_burst;
 	bool cmd_pause;
 	bool cmd_resume;
@@ -769,6 +771,7 @@ struct dma_filter {
  *	Since the enum dma_transfer_direction is not defined as bit flag for
  *	each type, the dma controller should set BIT(<TYPE>) and same
  *	should be checked by controller as well
+ * @min_burst: min burst capability per-transfer
  * @max_burst: max burst capability per-transfer
  * @residue_granularity: granularity of the transfer residue reported
  *	by tx_status
@@ -839,6 +842,7 @@ struct dma_device {
 	u32 src_addr_widths;
 	u32 dst_addr_widths;
 	u32 directions;
+	u32 min_burst;
 	u32 max_burst;
 	bool descriptor_reuse;
 	enum dma_residue_granularity residue_granularity;
-- 
2.26.2


  parent reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-23  0:58 [PATCH v8 00/10] dmaengine: dw: Take Baikal-T1 SoC DW DMAC peculiarities into account Serge Semin
2020-07-23  0:58 ` [PATCH v8 01/10] dt-bindings: dma: dw: Convert DW DMAC to DT binding Serge Semin
2020-07-23  0:58 ` [PATCH v8 02/10] dt-bindings: dma: dw: Add max burst transaction length property Serge Semin
2020-07-23  0:58 ` Serge Semin [this message]
2020-07-23  0:58 ` [PATCH v8 04/10] dmaengine: Introduce max SG burst capability Serge Semin
2020-07-23  0:58 ` [PATCH v8 05/10] dmaengine: Introduce DMA-device device_caps callback Serge Semin
2020-07-23  0:58 ` [PATCH v8 06/10] dmaengine: dw: Take HC_LLP flag into account for noLLP auto-config Serge Semin
2020-07-23  0:58 ` [PATCH v8 07/10] dmaengine: dw: Set DMA device max segment size parameter Serge Semin
2020-07-23  0:58 ` [PATCH v8 08/10] dmaengine: dw: Initialize min and max burst DMA device capability Serge Semin
2020-07-23  0:58 ` [PATCH v8 09/10] dmaengine: dw: Introduce max burst length hw config Serge Semin
2020-07-23  0:58 ` [PATCH v8 10/10] dmaengine: dw: Initialize max_sg_burst capability Serge Semin
2020-07-27  9:01 ` [PATCH v8 00/10] dmaengine: dw: Take Baikal-T1 SoC DW DMAC peculiarities into account Vinod Koul
2020-07-27 20:55   ` Serge Semin

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