From patchwork Mon Dec 2 19:40:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerhard Engleder X-Patchwork-Id: 846922 Received: from mx09lb.world4you.com (mx09lb.world4you.com [81.19.149.119]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BCC11632FE for ; Mon, 2 Dec 2024 19:54:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=81.19.149.119 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733169284; cv=none; b=MJS/uO+GJuklWnriV4gEc+WtOyphgK81vXJJJ0nODkqHcg3/Omi8hb3fR9VlBwlWpYusTRxYMkFgTXj2WHhWUD51RrX7tLYfcGx4cp3ILQYYoO4YhWc1Xh9eOeF2JNhL/WIXHaKMplLKBOgK15diNvfkqGDxmIcLzIufJRuLpR0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733169284; c=relaxed/simple; bh=YIxq/TSNUB75Ycju7QBiaDziLp8ePJF4INQtEYQdi+w=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=YjXUg2Ew3RYSqW/lUGgLmnYyqNqBLyIGCQ+38C8A626meohZ1HeWkHOyE4+xVPVo0B+lkK24mJ53GCWm/gHscZzZx7VphSfj2NHWMJpOgScyJyK4+eXb/LjYBrHTuOs/ZXbltCG99U8NaKssIKFfOWnXNSngoyM2u86FpFNNplc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=engleder-embedded.com; spf=pass smtp.mailfrom=engleder-embedded.com; dkim=pass (1024-bit key) header.d=engleder-embedded.com header.i=@engleder-embedded.com header.b=NdOdTqhu; arc=none smtp.client-ip=81.19.149.119 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=engleder-embedded.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=engleder-embedded.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=engleder-embedded.com header.i=@engleder-embedded.com header.b="NdOdTqhu" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=engleder-embedded.com; s=dkim11; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=IlACcdXV8CrVzrVLXDzruKEzZn5/jfzoXlw3Bo/u2Q8=; b=NdOdTqhu3DrGPnR0P92eSmQ1tQ UtYhcTzu4kyBf7dvQqNwcyR6k7tpAI4p/mXhB0MC0ila23Nz430agWbTOpoSbrZ0GwP58HsqDwt9M xg7pHM/dkU+9EYQr2EOCdW+JwDUroyBn+LA+Ro/+l1SfgAMtaU4bDgylDKISMFNJrC+0=; Received: from [88.117.62.55] (helo=hornet.engleder.at) by mx09lb.world4you.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tICHE-000000001yg-0Seo; Mon, 02 Dec 2024 20:40:12 +0100 From: Gerhard Engleder To: linux-spi@vger.kernel.org Cc: broonie@kernel.org, Gerhard Engleder , Gerhard Engleder Subject: [PATCH] spi: spi-kspi2: Add KEBA SPI controller support Date: Mon, 2 Dec 2024 20:40:03 +0100 Message-Id: <20241202194003.57679-1-gerhard@engleder-embedded.com> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-AV-Do-Run: Yes X-ACL-Warn: X-W4Y-Internal From: Gerhard Engleder The KEBA SPI controller is found in the system FPGA of KEBA PLC devices. It is used to connect the SPI flash chip of the FPGA and some SPI devices. It is a simple SPI controller with configurable speed. The hardware supports only single byte transfers. There are no FIFOs or interrupts. Signed-off-by: Gerhard Engleder --- drivers/spi/Kconfig | 12 ++ drivers/spi/Makefile | 1 + drivers/spi/spi-kspi2.c | 431 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 444 insertions(+) create mode 100644 drivers/spi/spi-kspi2.c diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index f51f9466e518..ea8a31032927 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -542,6 +542,18 @@ config SPI_JCORE This enables support for the SPI master controller in the J-Core synthesizable, open source SoC. +config SPI_KSPI2 + tristate "Support for KEBA SPI master type 2 hardware" + depends on HAS_IOMEM + depends on KEBA_CP500 || COMPILE_TEST + select AUXILIARY_BUS + help + This driver supports KEBA SPI master type 2 FPGA implementation, + as found on CP500 devices for example. + + This driver can also be built as a module. If so, the module + will be called spi-kspi2. + config SPI_LM70_LLP tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)" depends on PARPORT diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index aea5e54de195..9db7554c1864 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -74,6 +74,7 @@ obj-$(CONFIG_SPI_INTEL_PCI) += spi-intel-pci.o obj-$(CONFIG_SPI_INTEL_PLATFORM) += spi-intel-platform.o obj-$(CONFIG_SPI_LANTIQ_SSC) += spi-lantiq-ssc.o obj-$(CONFIG_SPI_JCORE) += spi-jcore.o +obj-$(CONFIG_SPI_KSPI2) += spi-kspi2.o obj-$(CONFIG_SPI_LJCA) += spi-ljca.o obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o obj-$(CONFIG_SPI_LOONGSON_CORE) += spi-loongson-core.o diff --git a/drivers/spi/spi-kspi2.c b/drivers/spi/spi-kspi2.c new file mode 100644 index 000000000000..ca73ec52ce63 --- /dev/null +++ b/drivers/spi/spi-kspi2.c @@ -0,0 +1,431 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) KEBA Industrial Automation Gmbh 2024 + * + * Driver for KEBA SPI host controller type 2 FPGA IP core + */ + +#include +#include +#include + +#define KSPI2 "kspi2" + +#define KSPI2_CLK_FREQ_REG 0x03 +#define KSPI2_CLK_FREQ_MASK 0x0f +#define KSPI2_CLK_FREQ_62_5M 0x0 +#define KSPI2_CLK_FREQ_33_3M 0x1 +#define KSPI2_CLK_FREQ_125M 0x2 +#define KSPI2_CLK_FREQ_50M 0x3 +#define KSPI2_CLK_FREQ_100M 0x4 + +#define KSPI2_CONTROL_REG 0x04 +#define KSPI2_CONTROL_CLK_DIV_MAX 0x0f +#define KSPI2_CONTROL_CLK_DIV_MASK 0x0f +#define KSPI2_CONTROL_CPHA 0x10 +#define KSPI2_CONTROL_CPOL 0x20 +#define KSPI2_CONTROL_CLK_MODE_MASK 0x30 +#define KSPI2_CONTROL_INIT KSPI2_CONTROL_CLK_DIV_MAX + +#define KSPI2_STATUS_REG 0x08 +#define KSPI2_STATUS_IN_USE 0x01 +#define KSPI2_STATUS_BUSY 0x02 + +#define KSPI2_DATA_REG 0x0c + +#define KSPI2_CS_NR_REG 0x10 +#define KSPI2_CS_NR_NONE 0xff + +#define KSPI2_MODE_BITS (SPI_CPHA | SPI_CPOL) +#define KSPI2_NUM_CS 255 + +#define KSPI2_SPEED_HZ_MIN(kspi) (kspi->base_speed_hz / 65536) +#define KSPI2_SPEED_HZ_MAX(kspi) (kspi->base_speed_hz / 2) + +/* timeout is 10 times the time to transfer one byte at slowest clock */ +#define KSPI2_XFER_TIMEOUT_US(kspi) (USEC_PER_SEC / \ + KSPI2_SPEED_HZ_MIN(kspi) * 8 * 10) + +#define KSPI2_INUSE_SLEEP_US (2 * USEC_PER_MSEC) +#define KSPI2_INUSE_TIMEOUT_US (10 * USEC_PER_SEC) + +struct kspi2 { + struct keba_spi_auxdev *auxdev; + void __iomem *base; + struct spi_controller *host; + + u32 base_speed_hz; /* SPI base clock frequency in HZ */ + u8 control_shadow; + + struct spi_device **device; + int device_size; +}; + +static int kspi2_inuse_lock(struct kspi2 *kspi) +{ + u8 sts; + int ret; + + /* + * The SPI controller has an IN_USE bit for locking access to the + * controller. This enables the use of the SPI controller by other none + * Linux processors. + * + * If the SPI controller is free, then the first read returns + * IN_USE == 0. After that the SPI controller is locked and further + * reads of IN_USE return 1. + * + * The SPI controller is unlocked by writing 1 into IN_USE. + * + * The IN_USE bit acts as a hardware semaphore for the SPI controller. + * Poll for semaphore, but sleep while polling to free the CPU. + */ + ret = readb_poll_timeout(kspi->base + KSPI2_STATUS_REG, + sts, (sts & KSPI2_STATUS_IN_USE) == 0, + KSPI2_INUSE_SLEEP_US, KSPI2_INUSE_TIMEOUT_US); + if (ret != 0) + dev_warn(&kspi->auxdev->auxdev.dev, "%s err!\n", __func__); + + return ret; +} + +static void kspi2_inuse_unlock(struct kspi2 *kspi) +{ + /* unlock the controller by writing 1 into IN_USE */ + iowrite8(KSPI2_STATUS_IN_USE, kspi->base + KSPI2_STATUS_REG); +} + +static int kspi2_prepare_hardware(struct spi_controller *host) +{ + struct kspi2 *kspi = spi_controller_get_devdata(host); + + /* lock hardware semaphore before actual use of controller */ + return kspi2_inuse_lock(kspi); +} + +static int kspi2_unprepare_hardware(struct spi_controller *host) +{ + struct kspi2 *kspi = spi_controller_get_devdata(host); + + /* unlock hardware semaphore after actual use of controller */ + kspi2_inuse_unlock(kspi); + + return 0; +} + +static u8 kspi2_calc_minimal_divider(struct kspi2 *kspi, u32 max_speed_hz) +{ + u8 div; + + /* + * Divider values 2, 4, 8, 16, ..., 65536 are possible. They are coded + * as 0, 1, 2, 3, ..., 15 in the CONTROL_CLK_DIV bit. + */ + for (div = 0; div < KSPI2_CONTROL_CLK_DIV_MAX; div++) { + if ((kspi->base_speed_hz >> (div + 1)) <= max_speed_hz) + return div; + } + + /* return divider for slowest clock if loop fails to find one */ + return KSPI2_CONTROL_CLK_DIV_MAX; +} + +static void kspi2_write_control_reg(struct kspi2 *kspi, u8 val, u8 mask) +{ + /* write control register only when necessary to improve performance */ + if (val != (kspi->control_shadow & mask)) { + kspi->control_shadow = (kspi->control_shadow & ~mask) | val; + iowrite8(kspi->control_shadow, kspi->base + KSPI2_CONTROL_REG); + } +} + +static int kspi2_txrx_byte(struct kspi2 *kspi, u8 tx, u8 *rx) +{ + u8 sts; + int ret; + + /* start transfer by writing TX byte */ + iowrite8(tx, kspi->base + KSPI2_DATA_REG); + + /* wait till finished (BUSY == 0) */ + ret = readb_poll_timeout(kspi->base + KSPI2_STATUS_REG, + sts, (sts & KSPI2_STATUS_BUSY) == 0, + 0, KSPI2_XFER_TIMEOUT_US(kspi)); + if (ret != 0) + return ret; + + /* read RX byte */ + if (rx) + *rx = ioread8(kspi->base + KSPI2_DATA_REG); + + return 0; +} + +static int kspi2_process_transfer(struct kspi2 *kspi, struct spi_transfer *t) +{ + u8 tx = 0; + u8 rx; + int i; + int ret; + + for (i = 0; i < t->len; i++) { + if (t->tx_buf) + tx = ((const u8 *)t->tx_buf)[i]; + + ret = kspi2_txrx_byte(kspi, tx, &rx); + if (ret) + return ret; + + if (t->rx_buf) + ((u8 *)t->rx_buf)[i] = rx; + } + + return 0; +} + +static int kspi2_setup_transfer(struct kspi2 *kspi, + struct spi_device *spi, + struct spi_transfer *t) +{ + u32 max_speed_hz = spi->max_speed_hz; + u8 clk_div; + + /* + * spi_device (spi) has default parameters. Some of these can be + * overwritten by parameters in spi_transfer (t). + */ + if (t->bits_per_word && ((t->bits_per_word % 8) != 0)) { + dev_err(&spi->dev, "Word width %d not supported!\n", + t->bits_per_word); + + return -EINVAL; + } + + if (t->speed_hz && (t->speed_hz < max_speed_hz)) + max_speed_hz = t->speed_hz; + + clk_div = kspi2_calc_minimal_divider(kspi, max_speed_hz); + kspi2_write_control_reg(kspi, clk_div, KSPI2_CONTROL_CLK_DIV_MASK); + + return 0; +} + +static int kspi2_transfer_one(struct spi_controller *host, + struct spi_device *spi, + struct spi_transfer *t) +{ + struct kspi2 *kspi = spi_controller_get_devdata(host); + int ret; + + ret = kspi2_setup_transfer(kspi, spi, t); + if (ret != 0) + return ret; + + if (t->len) { + ret = kspi2_process_transfer(kspi, t); + if (ret != 0) + return ret; + } + + return 0; +} + +static void kspi2_set_cs(struct spi_device *spi, bool enable) +{ + struct spi_controller *host = spi->controller; + struct kspi2 *kspi = spi_controller_get_devdata(host); + + /* controller is using active low chip select signals by design */ + if (!enable) + iowrite8(spi_get_chipselect(spi, 0), kspi->base + KSPI2_CS_NR_REG); + else + iowrite8(KSPI2_CS_NR_NONE, kspi->base + KSPI2_CS_NR_REG); +} + +static int kspi2_prepare_message(struct spi_controller *host, + struct spi_message *msg) +{ + struct kspi2 *kspi = spi_controller_get_devdata(host); + struct spi_device *spi = msg->spi; + u8 mode = 0; + + /* setup SPI clock phase and polarity */ + if (spi->mode & SPI_CPHA) + mode |= KSPI2_CONTROL_CPHA; + if (spi->mode & SPI_CPOL) + mode |= KSPI2_CONTROL_CPOL; + kspi2_write_control_reg(kspi, mode, KSPI2_CONTROL_CLK_MODE_MASK); + + return 0; +} + +static int kspi2_setup(struct spi_device *spi) +{ + struct kspi2 *kspi = spi_controller_get_devdata(spi->controller); + + /* + * Check only parameters. Actual setup is done in kspi2_prepare_message + * and directly before the SPI transfer starts. + */ + + if (spi->mode & ~KSPI2_MODE_BITS) { + dev_err(&spi->dev, "Mode %d not supported!\n", spi->mode); + + return -EINVAL; + } + + if ((spi->bits_per_word % 8) != 0) { + dev_err(&spi->dev, "Word width %d not supported!\n", + spi->bits_per_word); + + return -EINVAL; + } + + if ((spi->max_speed_hz == 0) || + (spi->max_speed_hz > KSPI2_SPEED_HZ_MAX(kspi))) + spi->max_speed_hz = KSPI2_SPEED_HZ_MAX(kspi); + + if (spi->max_speed_hz < KSPI2_SPEED_HZ_MIN(kspi)) { + dev_err(&spi->dev, "Requested speed of %d Hz is too low!\n", + spi->max_speed_hz); + + return -EINVAL; + } + + return 0; +} + +static void kspi2_unregister_devices(struct kspi2 *kspi) +{ + int i; + + for (i = 0; i < kspi->device_size; i++) { + struct spi_device *device = kspi->device[i]; + + if (device) + spi_unregister_device(device); + } +} + +static int kspi2_register_devices(struct kspi2 *kspi) +{ + struct spi_board_info *info = kspi->auxdev->info; + int i; + + /* register all known SPI devices */ + for (i = 0; i < kspi->auxdev->info_size; i++) { + struct spi_device *device = spi_new_device(kspi->host, &info[i]); + + if (!device) { + kspi2_unregister_devices(kspi); + + return -ENODEV; + } + kspi->device[i] = device; + } + + return 0; +} + +static void kspi2_init(struct kspi2 *kspi) +{ + iowrite8(KSPI2_CONTROL_INIT, kspi->base + KSPI2_CONTROL_REG); + kspi->control_shadow = KSPI2_CONTROL_INIT; + + iowrite8(KSPI2_CS_NR_NONE, kspi->base + KSPI2_CS_NR_REG); +} + +static int kspi2_probe(struct auxiliary_device *auxdev, + const struct auxiliary_device_id *id) +{ + struct device *dev = &auxdev->dev; + struct spi_controller *host; + struct kspi2 *kspi; + u8 clk_reg; + int ret; + + host = devm_spi_alloc_host(dev, sizeof(struct kspi2)); + if (!host) + return -ENOMEM; + kspi = spi_controller_get_devdata(host); + kspi->auxdev = container_of(auxdev, struct keba_spi_auxdev, auxdev); + kspi->host = host; + kspi->device = devm_kcalloc(dev, kspi->auxdev->info_size, + sizeof(*kspi->device), GFP_KERNEL); + if (!kspi->device) + return -ENOMEM; + kspi->device_size = kspi->auxdev->info_size; + auxiliary_set_drvdata(auxdev, kspi); + + kspi->base = devm_ioremap_resource(dev, &kspi->auxdev->io); + if (IS_ERR(kspi->base)) + return PTR_ERR(kspi->base); + + /* read the SPI base clock frequency */ + clk_reg = ioread8(kspi->base + KSPI2_CLK_FREQ_REG); + switch (clk_reg & KSPI2_CLK_FREQ_MASK) { + case KSPI2_CLK_FREQ_62_5M: + kspi->base_speed_hz = 62500000; break; + case KSPI2_CLK_FREQ_33_3M: + kspi->base_speed_hz = 33333333; break; + case KSPI2_CLK_FREQ_125M: + kspi->base_speed_hz = 125000000; break; + case KSPI2_CLK_FREQ_50M: + kspi->base_speed_hz = 50000000; break; + case KSPI2_CLK_FREQ_100M: + kspi->base_speed_hz = 100000000; break; + default: + dev_err(dev, "Undefined SPI base clock frequency!\n"); + return -ENODEV; + } + + kspi2_init(kspi); + + host->bus_num = -1; + host->num_chipselect = KSPI2_NUM_CS; + host->mode_bits = KSPI2_MODE_BITS; + host->setup = kspi2_setup; + host->prepare_transfer_hardware = kspi2_prepare_hardware; + host->unprepare_transfer_hardware = kspi2_unprepare_hardware; + host->prepare_message = kspi2_prepare_message; + host->set_cs = kspi2_set_cs; + host->transfer_one = kspi2_transfer_one; + ret = devm_spi_register_controller(dev, host); + if (ret) { + dev_err(dev, "Failed to register host (%d)!\n", ret); + return ret; + } + + ret = kspi2_register_devices(kspi); + if (ret) { + dev_err(dev, "Failed to register devices (%d)!\n", ret); + return ret; + } + + return 0; +} + +static void kspi2_remove(struct auxiliary_device *auxdev) +{ + struct kspi2 *kspi = auxiliary_get_drvdata(auxdev); + + kspi2_unregister_devices(kspi); +} + +static const struct auxiliary_device_id kspi2_devtype_aux[] = { + { .name = "keba.spi" }, + { }, +}; +MODULE_DEVICE_TABLE(auxiliary, kspi2_devtype_aux); + +static struct auxiliary_driver kspi2_driver_aux = { + .name = KSPI2, + .id_table = kspi2_devtype_aux, + .probe = kspi2_probe, + .remove = kspi2_remove, +}; +module_auxiliary_driver(kspi2_driver_aux); + +MODULE_AUTHOR("Gerhard Engleder "); +MODULE_DESCRIPTION("KEBA SPI host controller driver"); +MODULE_LICENSE("GPL");