Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754106AbcLNUA7 (ORCPT ); Wed, 14 Dec 2016 15:00:59 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:34846 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbcLNUA6 (ORCPT ); Wed, 14 Dec 2016 15:00:58 -0500 Subject: Re: [PATCH v3 2/2] FPGA: Add TS-7300 FPGA manager To: Moritz Fischer References: <20161214023553.9377-1-f.fainelli@gmail.com> <20161214023553.9377-3-f.fainelli@gmail.com> Cc: Linux Kernel Mailing List , linux-arm-kernel , Alan Tull , Russell King , rmallon@gmail.com, H Hartley Sweeten , linux-fpga@vger.kernel.org From: Florian Fainelli Message-ID: Date: Wed, 14 Dec 2016 10:55:20 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6366 Lines: 163 On 12/13/2016 10:07 PM, Moritz Fischer wrote: > Hi Florian, > > On Tue, Dec 13, 2016 at 6:35 PM, Florian Fainelli wrote: >> Add support for loading bitstreams on the Altera Cyclone II FPGA >> populated on the TS-7300 board. This is done through the configuration >> and data registers offered through a memory interface between the EP93xx >> SoC and the FPGA via an intermediate CPLD device. >> >> The EP93xx SoC on the TS-7300 does not have direct means of configuring >> the on-board FPGA other than by using the special memory mapped >> interface to the CPLD. No other entity on the system can control the >> FPGA bitstream. >> >> Signed-off-by: Florian Fainelli >> --- >> drivers/fpga/Kconfig | 7 ++ >> drivers/fpga/Makefile | 1 + >> drivers/fpga/ts73xx-fpga.c | 163 +++++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 171 insertions(+) >> create mode 100644 drivers/fpga/ts73xx-fpga.c >> >> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig >> index ce861a2853a4..d9cbef60db80 100644 >> --- a/drivers/fpga/Kconfig >> +++ b/drivers/fpga/Kconfig >> @@ -33,6 +33,13 @@ config FPGA_MGR_SOCFPGA_A10 >> help >> FPGA manager driver support for Altera Arria10 SoCFPGA. >> >> +config FPGA_MGR_TS73XX >> + tristate "Technologic Systems TS-73xx SBC FPGA Manager" >> + depends on ARCH_EP93XX && MACH_TS72XX >> + help >> + FPGA manager driver support for the Altera Cyclone II FPGA >> + present on the TS-73xx SBC boards. >> + >> config FPGA_MGR_ZYNQ_FPGA >> tristate "Xilinx Zynq FPGA" >> depends on ARCH_ZYNQ || COMPILE_TEST >> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile >> index 8df07bcf42a6..a1160169e6d9 100644 >> --- a/drivers/fpga/Makefile >> +++ b/drivers/fpga/Makefile >> @@ -8,6 +8,7 @@ obj-$(CONFIG_FPGA) += fpga-mgr.o >> # FPGA Manager Drivers >> obj-$(CONFIG_FPGA_MGR_SOCFPGA) += socfpga.o >> obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10) += socfpga-a10.o >> +obj-$(CONFIG_FPGA_MGR_TS73XX) += ts73xx-fpga.o >> obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA) += zynq-fpga.o >> >> # FPGA Bridge Drivers >> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c >> new file mode 100644 >> index 000000000000..38d78d8c6b1e >> --- /dev/null >> +++ b/drivers/fpga/ts73xx-fpga.c >> @@ -0,0 +1,163 @@ >> +/* >> + * Technologic Systems TS-73xx SBC FPGA loader >> + * >> + * Copyright (C) 2016 Florian Fainelli >> + * >> + * FPGA Manager Driver for the on-board Altera Cyclone II FPGA found on >> + * TS-7300, heavily based on load_fpga.c in their vendor tree. >> + * >> + * 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; version 2 of the License. >> + * >> + * 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. >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#define TS73XX_FPGA_DATA_REG 0 >> +#define TS73XX_FPGA_CONFIG_REG 1 >> + >> +#define TS73XX_FPGA_WRITE_DONE 0x1 >> +#define TS73XX_FPGA_WRITE_DONE_TIMEOUT 1000 /* us */ >> +#define TS73XX_FPGA_RESET 0x2 >> +#define TS73XX_FPGA_RESET_LOW_DELAY 30 /* us */ >> +#define TS73XX_FPGA_RESET_HIGH_DELAY 80 /* us */ >> +#define TS73XX_FPGA_LOAD_OK 0x4 >> +#define TS73XX_FPGA_CONFIG_LOAD 0x8 >> + >> +struct ts73xx_fpga_priv { >> + void __iomem *io_base; >> + struct device *dev; >> +}; >> + >> +static enum fpga_mgr_states ts73xx_fpga_state(struct fpga_manager *mgr) >> +{ >> + return FPGA_MGR_STATE_UNKNOWN; >> +} >> + >> +static int ts73xx_fpga_write_init(struct fpga_manager *mgr, >> + struct fpga_image_info *info, >> + const char *buf, size_t count) >> +{ >> + struct ts73xx_fpga_priv *priv = mgr->priv; >> + >> + /* Reset the FPGA */ >> + writeb(0, priv->io_base + TS73XX_FPGA_CONFIG_REG); >> + udelay(TS73XX_FPGA_RESET_LOW_DELAY); >> + writeb(TS73XX_FPGA_RESET, priv->io_base + TS73XX_FPGA_CONFIG_REG); >> + udelay(TS73XX_FPGA_RESET_HIGH_DELAY); >> + >> + return 0; >> +} >> + >> +static int ts73xx_fpga_write(struct fpga_manager *mgr, const char *buf, >> + size_t count) >> +{ >> + struct ts73xx_fpga_priv *priv = mgr->priv; >> + size_t i = 0; >> + int ret; >> + u8 reg; >> + >> + while (count--) { >> + ret = readb_poll_timeout(priv->io_base + TS73XX_FPGA_CONFIG_REG, >> + reg, !(reg & TS73XX_FPGA_WRITE_DONE), >> + 1, TS73XX_FPGA_WRITE_DONE_TIMEOUT); >> + if (ret < 0) >> + return ret; >> + >> + writeb(buf[i], priv->io_base + TS73XX_FPGA_DATA_REG); >> + i++; >> + } >> + > > >> + usleep_range(1000, 2000); >> + reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG); >> + reg |= TS73XX_FPGA_CONFIG_LOAD; >> + writeb(reg, priv->io_base + TS73XX_FPGA_CONFIG_REG); >> + usleep_range(1000, 2000); > > > > Just to clarify is this block what triggers the actual write? I'm asking because > I'm wondering if in the current implementation the ts73xx_fpga_write() function > can be called multiple times in your implementation before you finally get to > the write complete callback. My understanding is that, yes, this triggers the final write. You are right that ts73xx_fpga_write() can be called multiple times. It sounds like what my write_complete function does right now is just return that we successfully completed the bistream write, but this snippet that you are quoting should actually be moved into write_complete. Does that sound reasonable? -- Florian