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From:   Nikita Yushchenko <nikita.yoush@cogentembedded.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Lee Jones <lee.jones@linaro.org>
Cc:     linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
        Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Subject: [PATCH v2] staging: most: dim2: force fcnt=3 on Renesas GEN3
Date:   Mon, 27 Sep 2021 18:58:05 +0300
Message-Id: <20210927155804.27877-1-nikita.yoush@cogentembedded.com>
In-Reply-To: <YVHoXyULqXsWktMN@kroah.com>
References: <YVHoXyULqXsWktMN@kroah.com>
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Per Renesas datasheet, MLBC0 register's fcnt field in the embedded
dim2 module must be never set to value different from 3.

Enforce that, via an optional field in struct dim2_platform_data.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
---
Changes from v1:
- set dev_fcnt via if statement, not conditional expression

 drivers/staging/most/dim2/dim2.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index 093ef9a2b291..9300040ec84c 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -108,6 +108,7 @@ struct dim2_hdm {
 struct dim2_platform_data {
 	int (*enable)(struct platform_device *pdev);
 	void (*disable)(struct platform_device *pdev);
+	u8 fcnt;
 };
 
 #define iface_to_hdm(iface) container_of(iface, struct dim2_hdm, most_iface)
@@ -731,7 +732,7 @@ static int dim2_probe(struct platform_device *pdev)
 	struct dim2_hdm *dev;
 	struct resource *res;
 	int ret, i;
-	u8 hal_ret;
+	u8 dev_fcnt, hal_ret;
 	int irq;
 
 	enum { MLB_INT_IDX, AHB0_INT_IDX };
@@ -770,8 +771,14 @@ static int dim2_probe(struct platform_device *pdev)
 
 	dev->disable_platform = pdata ? pdata->disable : NULL;
 
-	dev_info(&pdev->dev, "sync: num of frames per sub-buffer: %u\n", fcnt);
-	hal_ret = dim_startup(dev->io_base, dev->clk_speed, fcnt);
+	if (pdata && pdata->fcnt)
+		dev_fcnt = pdata->fcnt;
+	else
+		dev_fcnt = fcnt;
+
+	dev_info(&pdev->dev, "sync: num of frames per sub-buffer: %u\n",
+		 dev_fcnt);
+	hal_ret = dim_startup(dev->io_base, dev->clk_speed, dev_fcnt);
 	if (hal_ret != DIM_NO_ERROR) {
 		dev_err(&pdev->dev, "dim_startup failed: %d\n", hal_ret);
 		ret = -ENODEV;
@@ -1047,9 +1054,19 @@ static void rcar_m3_disable(struct platform_device *pdev)
 enum dim2_platforms { FSL_MX6, RCAR_H2, RCAR_M3 };
 
 static struct dim2_platform_data plat_data[] = {
-	[FSL_MX6] = { .enable = fsl_mx6_enable, .disable = fsl_mx6_disable },
-	[RCAR_H2] = { .enable = rcar_h2_enable, .disable = rcar_h2_disable },
-	[RCAR_M3] = { .enable = rcar_m3_enable, .disable = rcar_m3_disable },
+	[FSL_MX6] = {
+		.enable = fsl_mx6_enable,
+		.disable = fsl_mx6_disable,
+	},
+	[RCAR_H2] = {
+		.enable = rcar_h2_enable,
+		.disable = rcar_h2_disable,
+	},
+	[RCAR_M3] = {
+		.enable = rcar_m3_enable,
+		.disable = rcar_m3_disable,
+		.fcnt = 3,
+	},
 };
 
 static const struct of_device_id dim2_of_match[] = {
-- 
2.30.2