From patchwork Tue Oct 26 20:18:20 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cyril Chemparathy X-Patchwork-Id: 297482 Received: from bear.ext.ti.com (bear.ext.ti.com [192.94.94.41]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id oA2E0Q5i013845 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 2 Nov 2010 14:00:47 GMT Received: from dlep36.itg.ti.com ([157.170.170.91]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id oA2DwnSv008232 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 2 Nov 2010 08:58:49 -0500 Received: from linux.omap.com (localhost [127.0.0.1]) by dlep36.itg.ti.com (8.13.8/8.13.8) with ESMTP id oA2DwmuO018771; Tue, 2 Nov 2010 08:58:48 -0500 (CDT) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id A6A1880665; Tue, 2 Nov 2010 07:58:44 -0600 (CST) X-Original-To: davinci-linux-open-source@linux.davincidsp.com Delivered-To: davinci-linux-open-source@linux.davincidsp.com Received: from dlep35.itg.ti.com (dlep35.itg.ti.com [157.170.170.118]) by linux.omap.com (Postfix) with ESMTP id 444C380626 for ; Tue, 26 Oct 2010 15:18:42 -0500 (CDT) Received: from legion.dal.design.ti.com (localhost [127.0.0.1]) by dlep35.itg.ti.com (8.13.7/8.13.7) with ESMTP id o9QKIfja015242; Tue, 26 Oct 2010 15:18:41 -0500 (CDT) Received: from gtrgwdeb (gtrgwdeb.telogy.design.ti.com [158.218.102.24]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id o9QKIef11203; Tue, 26 Oct 2010 15:18:40 -0500 (CDT) Received: by gtrgwdeb (Postfix, from userid 39959) id D70AC1E2703; Tue, 26 Oct 2010 16:18:39 -0400 (EDT) From: Cyril Chemparathy To: davinci-linux-open-source@linux.davincidsp.com, spi-devel-general@lists.sourceforge.net, broonie@opensource.wolfsonmicro.com, lrg@slimlogic.co.uk, dbrownell@users.sourceforge.net, grant.likely@secretlab.ca, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, rpurdie@rpsys.net Subject: [PATCH v4 04/12] spi: add ti-ssp spi master driver Date: Tue, 26 Oct 2010 16:18:20 -0400 Message-Id: <1288124308-14999-5-git-send-email-cyril@ti.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1288124308-14999-1-git-send-email-cyril@ti.com> References: <1288124308-14999-1-git-send-email-cyril@ti.com> X-Mailman-Approved-At: Tue, 02 Nov 2010 07:57:07 -0600 X-BeenThere: davinci-linux-open-source@linux.davincidsp.com X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: davinci-linux-open-source-bounces@linux.davincidsp.com Errors-To: davinci-linux-open-source-bounces@linux.davincidsp.com X-Greylist: Sender succeeded STARTTLS authentication, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Tue, 02 Nov 2010 14:00:48 +0000 (UTC) diff --git a/arch/arm/mach-davinci/include/mach/ti_ssp.h b/arch/arm/mach-davinci/include/mach/ti_ssp.h index c98d0f2..bff8ef6 100644 --- a/arch/arm/mach-davinci/include/mach/ti_ssp.h +++ b/arch/arm/mach-davinci/include/mach/ti_ssp.h @@ -34,6 +34,11 @@ struct ti_ssp_data { struct ti_ssp_dev_data dev_data[2]; }; +struct ti_ssp_spi_data { + int num_cs; + void (*select)(int cs); +}; + /* * Sequencer port IO pin configuration bits. These do not correlate 1-1 with * the hardware. The iosel field in the port data combines iosel1 and iosel2, diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 7e631fa..37b10e3 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -314,6 +314,13 @@ config SPI_STMP3XXX help SPI driver for Freescale STMP37xx/378x SoC SSP interface +config SPI_TI_SSP + tristate "TI SSP Controller SPI Driver" + depends on TI_SSP + help + This selects an SPI master implementation using a TI sequencer + serial port. + config SPI_TXX9 tristate "Toshiba TXx9 SPI controller" depends on GENERIC_GPIO && CPU_TX49XX diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index e9cbd18..a427f3c 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -39,6 +39,7 @@ obj-$(CONFIG_SPI_PPC4xx) += spi_ppc4xx.o obj-$(CONFIG_SPI_S3C24XX_GPIO) += spi_s3c24xx_gpio.o obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx_hw.o obj-$(CONFIG_SPI_S3C64XX) += spi_s3c64xx.o +obj-$(CONFIG_SPI_TI_SSP) += spi_ti_ssp.o obj-$(CONFIG_SPI_TXX9) += spi_txx9.o obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o obj-$(CONFIG_SPI_XILINX_OF) += xilinx_spi_of.o diff --git a/drivers/spi/spi_ti_ssp.c b/drivers/spi/spi_ti_ssp.c new file mode 100644 index 0000000..3cb41c5 --- /dev/null +++ b/drivers/spi/spi_ti_ssp.c @@ -0,0 +1,396 @@ +/* + * Sequencer Serial Port (SSP) based SPI master driver + * + * Copyright (C) 2010 Texas Instruments Inc + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include + +#include + +#define MODE_BITS (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH) + +struct ti_ssp_spi { + const struct ti_ssp_spi_data *pdata; + struct spi_master *master; + struct device *dev; + spinlock_t lock; + struct list_head msg_queue; + struct completion complete; + int shutdown:1; + struct workqueue_struct *workqueue; + struct work_struct work; + u8 mode, bpw; + int cs_active; + u32 pc_en, pc_dis, pc_wr, pc_rd; +}; + +static u32 do_read_data(struct ti_ssp_spi *hw) +{ + u32 ret; + + ti_ssp_run(hw->dev, hw->pc_rd, 0, &ret); + return ret; +} + +static void do_write_data(struct ti_ssp_spi *hw, u32 data) +{ + ti_ssp_run(hw->dev, hw->pc_wr, data << (32 - hw->bpw), NULL); +} + +static int do_transfer(struct ti_ssp_spi *hw, struct spi_message *msg, + struct spi_transfer *t) +{ + int count; + + if (hw->bpw <= 8) { + u8 *rx = t->rx_buf; + const u8 *tx = t->tx_buf; + + for (count = 0; count < t->len; count += 1) { + if (t->tx_buf) + do_write_data(hw, *tx++); + if (t->rx_buf) + *rx++ = do_read_data(hw); + } + } else if (hw->bpw <= 16) { + u16 *rx = t->rx_buf; + const u16 *tx = t->tx_buf; + + for (count = 0; count < t->len; count += 2) { + if (t->tx_buf) + do_write_data(hw, *tx++); + if (t->rx_buf) + *rx++ = do_read_data(hw); + } + } else { + u32 *rx = t->rx_buf; + const u32 *tx = t->tx_buf; + + for (count = 0; count < t->len; count += 4) { + if (t->tx_buf) + do_write_data(hw, *tx++); + if (t->rx_buf) + *rx++ = do_read_data(hw); + } + } + + msg->actual_length += count; /* bytes transferred */ + + dev_dbg(&msg->spi->dev, "xfer %s%s, %d bytes, %d bpw, count %d%s\n", + t->tx_buf ? "tx" : "", t->rx_buf ? "rx" : "", t->len, + hw->bpw, count, (count < t->len) ? " (under)" : ""); + + return (count < t->len) ? -EIO : 0; /* left over data */ +} + +static void chip_select(struct ti_ssp_spi *hw, int cs_active) +{ + cs_active = !!cs_active; + if (cs_active == hw->cs_active) + return; + ti_ssp_run(hw->dev, cs_active ? hw->pc_en : hw->pc_dis, 0, NULL); + hw->cs_active = cs_active; +} + +#define __SHIFT_OUT(bits) (SSP_OPCODE_SHIFT | SSP_OUT_MODE | \ + cs_en | clk | SSP_COUNT((bits) * 2 - 1)) +#define __SHIFT_IN(bits) (SSP_OPCODE_SHIFT | SSP_IN_MODE | \ + cs_en | clk | SSP_COUNT((bits) * 2 - 1)) + +static int setup_xfer(struct ti_ssp_spi *hw, u8 bpw, u8 mode) +{ + int error, idx = 0; + u32 seqram[16]; + u32 cs_en, cs_dis, clk; + u32 topbits, botbits; + + mode &= MODE_BITS; + if (mode == hw->mode && bpw == hw->bpw) + return 0; + + cs_en = (mode & SPI_CS_HIGH) ? SSP_CS_HIGH : SSP_CS_LOW; + cs_dis = (mode & SPI_CS_HIGH) ? SSP_CS_LOW : SSP_CS_HIGH; + clk = (mode & SPI_CPOL) ? SSP_CLK_HIGH : SSP_CLK_LOW; + + /* Construct instructions */ + + /* Disable Chip Select */ + hw->pc_dis = idx; + seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_dis | clk; + seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_dis | clk; + + /* Enable Chip Select */ + hw->pc_en = idx; + seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_en | clk; + seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; + + /* Reads and writes need to be split for bpw > 16 */ + topbits = (bpw > 16) ? 16 : bpw; + botbits = bpw - topbits; + + /* Write */ + hw->pc_wr = idx; + seqram[idx++] = __SHIFT_OUT(topbits) | SSP_ADDR_REG; + if (botbits) + seqram[idx++] = __SHIFT_OUT(botbits) | SSP_DATA_REG; + seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; + + /* Read */ + hw->pc_rd = idx; + if (botbits) + seqram[idx++] = __SHIFT_IN(botbits) | SSP_ADDR_REG; + seqram[idx++] = __SHIFT_IN(topbits) | SSP_DATA_REG; + seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; + + error = ti_ssp_load(hw->dev, 0, seqram, idx); + if (error < 0) + return error; + + error = ti_ssp_set_mode(hw->dev, ((mode & SPI_CPHA) ? + 0 : SSP_EARLY_DIN)); + if (error < 0) + return error; + + hw->bpw = bpw; + hw->mode = mode; + + return error; +} + +static void ti_ssp_spi_work(struct work_struct *work) +{ + struct ti_ssp_spi *hw = container_of(work, struct ti_ssp_spi, work); + + spin_lock(&hw->lock); + + while (!list_empty(&hw->msg_queue)) { + struct spi_message *m; + struct spi_device *spi; + struct spi_transfer *t = NULL; + int status = 0; + + m = container_of(hw->msg_queue.next, struct spi_message, + queue); + + list_del_init(&m->queue); + + spin_unlock(&hw->lock); + + spi = m->spi; + + if (hw->pdata->select) + hw->pdata->select(spi->chip_select); + + list_for_each_entry(t, &m->transfers, transfer_list) { + int bpw = spi->bits_per_word; + int xfer_status; + + if (t->bits_per_word) + bpw = t->bits_per_word; + + if (setup_xfer(hw, bpw, spi->mode) < 0) + break; + + chip_select(hw, 1); + + xfer_status = do_transfer(hw, m, t); + if (xfer_status < 0) + status = xfer_status; + + if (t->delay_usecs) + udelay(t->delay_usecs); + + if (t->cs_change) + chip_select(hw, 0); + } + + chip_select(hw, 0); + m->status = status; + m->complete(m->context); + + spin_lock(&hw->lock); + } + + if (hw->shutdown) + complete(&hw->complete); + + spin_unlock(&hw->lock); +} + +static int ti_ssp_spi_setup(struct spi_device *spi) +{ + if (spi->bits_per_word > 32) + return -EINVAL; + + return 0; +} + +static int ti_ssp_spi_transfer(struct spi_device *spi, struct spi_message *m) +{ + struct ti_ssp_spi *hw; + struct spi_transfer *t; + int error = 0; + + m->actual_length = 0; + m->status = -EINPROGRESS; + + hw = spi_master_get_devdata(spi->master); + + if (list_empty(&m->transfers) || !m->complete) + return -EINVAL; + + list_for_each_entry(t, &m->transfers, transfer_list) { + if (t->len && !(t->rx_buf || t->tx_buf)) { + dev_err(&spi->dev, "invalid xfer, no buffer\n"); + return -EINVAL; + } + + if (t->len && t->rx_buf && t->tx_buf) { + dev_err(&spi->dev, "invalid xfer, full duplex\n"); + return -EINVAL; + } + + if (t->bits_per_word > 32) { + dev_err(&spi->dev, "invalid xfer width %d\n", + t->bits_per_word); + return -EINVAL; + } + } + + spin_lock(&hw->lock); + if (hw->shutdown) { + error = -ESHUTDOWN; + goto error_unlock; + } + list_add_tail(&m->queue, &hw->msg_queue); + queue_work(hw->workqueue, &hw->work); +error_unlock: + spin_unlock(&hw->lock); + return error; +} + +static int __devinit ti_ssp_spi_probe(struct platform_device *pdev) +{ + const struct ti_ssp_spi_data *pdata; + struct ti_ssp_spi *hw; + struct spi_master *master; + struct device *dev = &pdev->dev; + int error = 0; + + pdata = dev->platform_data; + if (!pdata) { + dev_err(dev, "platform data not found\n"); + return -EINVAL; + } + + master = spi_alloc_master(dev, sizeof(struct ti_ssp_spi)); + if (!master) { + dev_err(dev, "cannot allocate SPI master\n"); + return -ENOMEM; + } + + hw = spi_master_get_devdata(master); + platform_set_drvdata(pdev, hw); + + hw->master = master; + hw->dev = dev; + hw->pdata = pdata; + + spin_lock_init(&hw->lock); + init_completion(&hw->complete); + INIT_LIST_HEAD(&hw->msg_queue); + INIT_WORK(&hw->work, ti_ssp_spi_work); + + hw->workqueue = create_singlethread_workqueue(dev_name(dev)); + if (!hw->workqueue) { + error = -ENOMEM; + dev_err(dev, "work queue creation failed\n"); + goto error_wq; + } + + master->bus_num = pdev->id; + master->num_chipselect = hw->pdata->num_cs; + master->mode_bits = MODE_BITS; + master->flags = SPI_MASTER_HALF_DUPLEX; + master->setup = ti_ssp_spi_setup; + master->transfer = ti_ssp_spi_transfer; + + error = spi_register_master(master); + if (error) { + dev_err(dev, "master registration failed\n"); + goto error_reg; + } + + return 0; + +error_reg: + destroy_workqueue(hw->workqueue); +error_wq: + spi_master_put(master); + return error; +} + +static int __devexit ti_ssp_spi_remove(struct platform_device *pdev) +{ + struct ti_ssp_spi *hw = platform_get_drvdata(pdev); + int error; + + hw->shutdown = 1; + while (!list_empty(&hw->msg_queue)) { + error = wait_for_completion_interruptible(&hw->complete); + if (error < 0) { + hw->shutdown = 0; + return error; + } + } + destroy_workqueue(hw->workqueue); + spi_unregister_master(hw->master); + + return 0; +} + +static struct platform_driver ti_ssp_spi_driver = { + .probe = ti_ssp_spi_probe, + .remove = __devexit_p(ti_ssp_spi_remove), + .driver = { + .name = "ti-ssp-spi", + .owner = THIS_MODULE, + }, +}; + +static int __init ti_ssp_spi_init(void) +{ + return platform_driver_register(&ti_ssp_spi_driver); +} +subsys_initcall(ti_ssp_spi_init); + +static void __exit ti_ssp_spi_exit(void) +{ + platform_driver_unregister(&ti_ssp_spi_driver); +} +module_exit(ti_ssp_spi_exit); + +MODULE_DESCRIPTION("SSP SPI Master"); +MODULE_AUTHOR("Cyril Chemparathy"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:spi_ti_ssp");