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Wed, 05 Jun 2024 21:23:28 +0000 Received: from smtpav06.dal12v.mail.ibm.com (smtpav06.dal12v.mail.ibm.com [10.241.53.105]) by smtprelay04.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 455LNOR459900160 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 5 Jun 2024 21:23:27 GMT Received: from smtpav06.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BEB8158055; Wed, 5 Jun 2024 21:23:24 +0000 (GMT) Received: from smtpav06.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8134658069; Wed, 5 Jun 2024 21:23:24 +0000 (GMT) Received: from slate16.aus.stglabs.ibm.com (unknown [9.61.121.242]) by smtpav06.dal12v.mail.ibm.com (Postfix) with ESMTP; Wed, 5 Jun 2024 21:23:24 +0000 (GMT) From: Eddie James To: linux-fsi@lists.ozlabs.org Cc: eajames@linux.ibm.com, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org, broonie@kernel.org, andi.shyti@kernel.org, joel@jms.id.au, alistair@popple.id.au, jk@ozlabs.org, andrew@codeconstruct.com.au, linux-aspeed@lists.ozlabs.org, ninad@linux.ibm.com, lakshmiy@us.ibm.com Subject: [PATCH v4 38/40] spi: fsi: Calculate clock divider from local bus frequency Date: Wed, 5 Jun 2024 16:23:10 -0500 Message-Id: <20240605212312.349188-39-eajames@linux.ibm.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240605212312.349188-1-eajames@linux.ibm.com> References: <20240605212312.349188-1-eajames@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: pXJf5SWkcjqXjY5lUhHcF8kD5LZGfCph X-Proofpoint-GUID: pXJf5SWkcjqXjY5lUhHcF8kD5LZGfCph X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-06-05_02,2024-06-05_02,2024-05-17_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 phishscore=0 adultscore=0 priorityscore=1501 lowpriorityscore=0 bulkscore=0 clxscore=1015 impostorscore=0 malwarescore=0 spamscore=0 mlxlogscore=856 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2406050160 Use the new FSI device local bus clock to calculate the proper SPI clock divider. Signed-off-by: Eddie James Acked-by: Mark Brown --- drivers/spi/spi-fsi.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index fc9e33be1e0e7..e762690f1a390 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -40,6 +40,7 @@ #define SPI_FSI_CLOCK_CFG_SCK_RECV_DEL GENMASK_ULL(51, 44) #define SPI_FSI_CLOCK_CFG_SCK_NO_DEL BIT_ULL(51) #define SPI_FSI_CLOCK_CFG_SCK_DIV GENMASK_ULL(63, 52) +#define SPI_FSI_CLOCK_CFG_SCK_DIV_MIN 0x4 #define SPI_FSI_MMAP 0x4 #define SPI_FSI_DATA_TX 0x5 #define SPI_FSI_DATA_RX 0x6 @@ -70,6 +71,7 @@ struct fsi2spi { struct fsi_device *fsi; /* FSI2SPI CFAM engine device */ struct mutex lock; /* lock access to the device */ + u32 lbus_freq; }; struct fsi_spi { @@ -359,7 +361,7 @@ static int fsi_spi_transfer_data(struct fsi_spi *ctx, return 0; } -static int fsi_spi_transfer_init(struct fsi_spi *ctx) +static int fsi_spi_transfer_init(struct fsi_spi *ctx, u32 clock_div) { int loops = 0; int rc; @@ -370,7 +372,7 @@ static int fsi_spi_transfer_init(struct fsi_spi *ctx) u64 status = 0ULL; u64 wanted_clock_cfg = SPI_FSI_CLOCK_CFG_ECC_DISABLE | SPI_FSI_CLOCK_CFG_SCK_NO_DEL | - FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 19); + FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, clock_div); end = jiffies + msecs_to_jiffies(SPI_FSI_TIMEOUT_MS); do { @@ -421,6 +423,24 @@ static int fsi_spi_transfer_init(struct fsi_spi *ctx) return rc; } +static u32 fsi_spi_calculate_clock_div(struct fsi2spi *bridge, struct spi_device *dev, + struct spi_transfer *transfer) +{ + u32 div = 19; + + if (bridge->lbus_freq) { + u32 desired_speed_hz = transfer->speed_hz ?: dev->max_speed_hz; + + div = DIV_ROUND_UP(bridge->lbus_freq, desired_speed_hz); + if (div < SPI_FSI_CLOCK_CFG_SCK_DIV_MIN) + div = SPI_FSI_CLOCK_CFG_SCK_DIV_MIN; + + transfer->effective_speed_hz = bridge->lbus_freq / div; + } + + return div; +} + static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, struct spi_message *mesg) { @@ -429,6 +449,7 @@ static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, unsigned int len; struct spi_transfer *transfer; struct fsi_spi *ctx = spi_controller_get_devdata(ctlr); + u32 div; rc = fsi_spi_check_mux(ctx->bridge->fsi, ctx->dev); if (rc) @@ -446,7 +467,8 @@ static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, dev_dbg(ctx->dev, "Start tx of %d bytes.\n", transfer->len); - rc = fsi_spi_transfer_init(ctx); + div = fsi_spi_calculate_clock_div(ctx->bridge, mesg->spi, transfer); + rc = fsi_spi_transfer_init(ctx, div); if (rc < 0) goto error; @@ -533,6 +555,7 @@ static int fsi_spi_probe(struct device *dev) bridge->fsi = fsi; mutex_init(&bridge->lock); + bridge->lbus_freq = fsi_device_local_bus_frequency(fsi); for_each_available_child_of_node(dev->of_node, np) { u32 base; @@ -550,6 +573,10 @@ static int fsi_spi_probe(struct device *dev) ctlr->dev.of_node = np; ctlr->num_chipselect = of_get_available_child_count(np) ?: 1; + if (bridge->lbus_freq) { + ctlr->min_speed_hz = DIV_ROUND_UP(bridge->lbus_freq, 0xfff); + ctlr->max_speed_hz = bridge->lbus_freq / SPI_FSI_CLOCK_CFG_SCK_DIV_MIN; + } ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX; ctlr->max_transfer_size = fsi_spi_max_transfer_size; ctlr->transfer_one_message = fsi_spi_transfer_one_message;