From nobody Fri Dec 19 14:38:28 2025 Received: from relmlie5.idc.renesas.com (relmlor1.renesas.com [210.160.252.171]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C92302FD684; Wed, 5 Nov 2025 09:15:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.160.252.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762334146; cv=none; b=tgSxmPfvagED3gpgRJqkS4OIN5iDb2NXCmZ3PxXmS6zrI63tSC+3SW6zI0jXkZaAIp+KGnXAJ7fXNnTwUb2RcD4jyFVIFXBTa7vUBq5VeQ6qZm9k8fboiVEPA0MZ24BucaFoe3TH6t2jHx9ElMa3aveiMMi8Cyu76io0F0L9yI8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762334146; c=relaxed/simple; bh=UganWNkeKrLky13PVsdX6fI+hy19J24abS6vT+14ZUs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ei1fGRKUtQjx3yYgY/pAFL8K4y0b549WmZjMBLzBX9SNewZIHOY/F8a/2AvMQS6sUMtsJVAGBiFwk5Abuh59wt/ii5VrwDdYQSUs413IZdgKSB9qDy8oqvhvOF+r1c7WaTg5eZR7odXyb9NU8g+MuzKRzmkz6B98/ePjJPQpDWU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=renesas.com; spf=pass smtp.mailfrom=renesas.com; arc=none smtp.client-ip=210.160.252.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=renesas.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=renesas.com X-CSE-ConnectionGUID: DV18dhccRW+MJLJKzh6QHw== X-CSE-MsgGUID: 7CV0Q5bgTrCZk1+AzVhZ2w== Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie5.idc.renesas.com with ESMTP; 05 Nov 2025 18:15:44 +0900 Received: from demon-pc.localdomain (unknown [10.226.92.38]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id A3DF141763FB; Wed, 5 Nov 2025 18:15:39 +0900 (JST) From: Cosmin Tanislav To: Cc: Fabrizio Castro , Mark Brown , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Geert Uytterhoeven , Magnus Damm , Michael Turquette , Stephen Boyd , Philipp Zabel , linux-spi@vger.kernel.org, linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, Cosmin Tanislav Subject: [PATCH 10/14] spi: rzv2h-rspi: add support for loopback mode Date: Wed, 5 Nov 2025 11:13:54 +0200 Message-ID: <20251105091401.1462985-11-cosmin-gabriel.tanislav.xa@renesas.com> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251105091401.1462985-1-cosmin-gabriel.tanislav.xa@renesas.com> References: <20251105091401.1462985-1-cosmin-gabriel.tanislav.xa@renesas.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add support for loopback mode for debugging purposes, allowing us to test the SPI controller at the maximum SPI transfer clock without being limited by external wiring. Signed-off-by: Cosmin Tanislav --- drivers/spi/spi-rzv2h-rspi.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-rzv2h-rspi.c b/drivers/spi/spi-rzv2h-rspi.c index be45269e8853..da110efba971 100644 --- a/drivers/spi/spi-rzv2h-rspi.c +++ b/drivers/spi/spi-rzv2h-rspi.c @@ -24,6 +24,7 @@ /* Registers */ #define RSPI_SPDR 0x00 #define RSPI_SPCR 0x08 +#define RSPI_SPPCR 0x0e #define RSPI_SSLP 0x10 #define RSPI_SPBR 0x11 #define RSPI_SPSCR 0x13 @@ -40,6 +41,9 @@ #define RSPI_SPCR_SCKASE BIT(12) #define RSPI_SPCR_SPE BIT(0) =20 +/* Register SPPCR */ +#define RSPI_SPPCR_SPLP2 BIT(1) + /* Register SPBR */ #define RSPI_SPBR_SPR_MIN 0 #define RSPI_SPBR_SPR_PCLK_MIN 1 @@ -345,6 +349,7 @@ static int rzv2h_rspi_prepare_message(struct spi_contro= ller *ctlr, u8 bits_per_word; u32 conf32; u16 conf16; + u8 conf8; =20 /* Make sure SPCR.SPE is 0 before amending the configuration */ rzv2h_rspi_spe_disable(rspi); @@ -389,6 +394,10 @@ static int rzv2h_rspi_prepare_message(struct spi_contr= oller *ctlr, /* Use SPCMD0 only */ writeb(0x0, rspi->base + RSPI_SPSCR); =20 + /* Setup loopback */ + conf8 =3D FIELD_PREP(RSPI_SPPCR_SPLP2, !!(spi->mode & SPI_LOOP)); + writeb(conf8, rspi->base + RSPI_SPPCR); + /* Setup mode */ conf32 =3D FIELD_PREP(RSPI_SPCMD_CPOL, !!(spi->mode & SPI_CPOL)); conf32 |=3D FIELD_PREP(RSPI_SPCMD_CPHA, !!(spi->mode & SPI_CPHA)); @@ -490,7 +499,7 @@ static int rzv2h_rspi_probe(struct platform_device *pde= v) } =20 controller->mode_bits =3D SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | - SPI_LSB_FIRST; + SPI_LSB_FIRST | SPI_LOOP; controller->bits_per_word_mask =3D SPI_BPW_RANGE_MASK(4, 32); controller->prepare_message =3D rzv2h_rspi_prepare_message; controller->unprepare_message =3D rzv2h_rspi_unprepare_message; --=20 2.51.2