From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA58BC433F5 for ; Wed, 5 Oct 2022 10:49:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229608AbiJEKrY (ORCPT ); Wed, 5 Oct 2022 06:47:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229505AbiJEKrV (ORCPT ); Wed, 5 Oct 2022 06:47:21 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C109926492; Wed, 5 Oct 2022 03:47:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664966838; x=1696502838; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=Qvdvm6/Yzu7ojmkolJcq8JM8ELA489o7JaJRUu4mY5U=; b=IuoI0hTa7ArWrespAaoLf+8W3nQQa2Mrlwf2E3ditrFWFx4AysDHUJaC 8EmFCUAUJ/Fpfyo4kwpzzY9OS7wttI48w/JBpM26a8sePDJhlY8bATrcb jvFw11O/xA7ux3Vz63CPJu+PhEvx4IJHhhU76Gs/mMpWz4uWxeYA1xw0S XUf76pHoF7IDHI9dU1eiDi/0TC5CE3R+tvDsK8sj+WLhoc2+T48mqdMaK KXq5peKU9Pzc6OUos9DeqWnPMK7PQkd5aGfQmWlFCa56v4OpkntpfGOlj 08MC3kHmA554FeV0f06r2NERv01uz0Sjev+Ud50dO6mBBcWBylpNNx9p4 w==; X-IronPort-AV: E=McAfee;i="6500,9779,10490"; a="329543795" X-IronPort-AV: E=Sophos;i="5.95,159,1661842800"; d="scan'208";a="329543795" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2022 03:47:18 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10490"; a="869361684" X-IronPort-AV: E=Sophos;i="5.95,159,1661842800"; d="scan'208";a="869361684" Received: from refaase-mobl1.ger.corp.intel.com ([10.252.39.164]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2022 03:47:11 -0700 Date: Wed, 5 Oct 2022 13:47:08 +0300 (EEST) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: Matthew Gerlach cc: hao.wu@intel.com, yilun.xu@intel.com, russell.h.weight@intel.com, basheer.ahmed.muddebihal@intel.com, trix@redhat.com, mdf@kernel.org, linux-fpga@vger.kernel.org, linux-doc@vger.kernel.org, LKML , tianfei.zhang@intel.com, corbet@lwn.net, Greg Kroah-Hartman , linux-serial , Jiri Slaby , geert+renesas@glider.be, Andy Shevchenko , niklas.soderlund+renesas@ragnatech.se, macro@orcam.me.uk, johan@kernel.org, Lukas Wunner , kernel test robot Subject: Re: [PATCH v3 4/4] tty: serial: 8250: add DFL bus driver for Altera 16550. In-Reply-To: <20221004143718.1076710-5-matthew.gerlach@linux.intel.com> Message-ID: References: <20221004143718.1076710-1-matthew.gerlach@linux.intel.com> <20221004143718.1076710-5-matthew.gerlach@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On Tue, 4 Oct 2022, matthew.gerlach@linux.intel.com wrote: > From: Matthew Gerlach > > Add a Device Feature List (DFL) bus driver for the Altera > 16550 implementation of UART. > > Signed-off-by: Matthew Gerlach > Reported-by: kernel test robot > --- > v3: use passed in location of registers > use cleaned up functions for parsing parameters > > v2: clean up error messages > alphabetize header files > fix 'missing prototype' error by making function static > tried to sort Makefile and Kconfig better > --- > drivers/tty/serial/8250/8250_dfl.c | 177 +++++++++++++++++++++++++++++ > drivers/tty/serial/8250/Kconfig | 9 ++ > drivers/tty/serial/8250/Makefile | 1 + > 3 files changed, 187 insertions(+) > create mode 100644 drivers/tty/serial/8250/8250_dfl.c > > diff --git a/drivers/tty/serial/8250/8250_dfl.c b/drivers/tty/serial/8250/8250_dfl.c > new file mode 100644 > index 000000000000..110ad3a73459 > --- /dev/null > +++ b/drivers/tty/serial/8250/8250_dfl.c > @@ -0,0 +1,177 @@ > +static int dfl_uart_get_params(struct device *dev, void __iomem *dfh_base, resource_size_t max, > + struct uart_8250_port *uart) > +{ > + u64 v, fifo_len, reg_width; > + int off; > + > + if (!dfhv1_has_params(dfh_base)) { > + dev_err(dev, "missing required DFH parameters\n"); > + return -EINVAL; > + } > + > + off = dfhv1_find_param(dfh_base, max, DFHv1_PARAM_ID_CLK_FRQ); > + if (off < 0) { > + dev_err(dev, "missing CLK_FRQ param\n"); > + return -EINVAL; > + } > + > + uart->port.uartclk = readq(dfh_base + off); > + dev_dbg(dev, "UART_CLK_ID %u Hz\n", uart->port.uartclk); > + > + off = dfhv1_find_param(dfh_base, max, DFHv1_PARAM_ID_FIFO_LEN); > + if (off < 0) { > + dev_err(dev, "missing FIFO_LEN param\n"); > + return -EINVAL; > + } > + > + fifo_len = readq(dfh_base + off); > + dev_dbg(dev, "UART_FIFO_ID fifo_len %llu\n", fifo_len); > + > + switch (fifo_len) { > + case 32: > + uart->port.type = PORT_ALTR_16550_F32; > + break; > + > + case 64: > + uart->port.type = PORT_ALTR_16550_F64; > + break; > + > + case 128: > + uart->port.type = PORT_ALTR_16550_F128; > + break; > + > + default: > + dev_err(dev, "bad fifo_len %llu\n", fifo_len); I'd tell user "unsupported" rather than "bad". > + return -EINVAL; > + } > + > + off = dfhv1_find_param(dfh_base, max, DFHv1_PARAM_ID_REG_LAYOUT); > + if (off < 0) { > + dev_err(dev, "missing REG_LAYOUT param\n"); > + return -EINVAL; > + } > + > + v = readq(dfh_base + off); > + uart->port.regshift = FIELD_GET(DFHv1_PARAM_ID_REG_SHIFT, v); > + reg_width = FIELD_GET(DFHv1_PARAM_ID_REG_WIDTH, v); > + > + dev_dbg(dev, "UART_LAYOUT_ID width %lld shift %d\n", > + FIELD_GET(DFHv1_PARAM_ID_REG_WIDTH, v), (int)uart->port.regshift); Why not use reg_width directly? > + switch (reg_width) { > + case 4: > + uart->port.iotype = UPIO_MEM32; > + break; > + > + case 2: > + uart->port.iotype = UPIO_MEM16; > + break; > + > + default: > + dev_err(dev, "invalid reg_width %lld\n", reg_width); unsupported ? > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int dfl_uart_probe(struct dfl_device *dfl_dev) > +{ > + struct device *dev = &dfl_dev->dev; > + struct uart_8250_port uart; > + struct dfl_uart *dfluart; > + resource_size_t res_size; > + void __iomem *dfh_base; > + int ret; > + > + memset(&uart, 0, sizeof(uart)); > + uart.port.flags = UPF_IOREMAP; > + uart.port.mapbase = dfl_dev->csr_res.start; > + uart.port.mapsize = resource_size(&dfl_dev->csr_res); > + > + dfluart = devm_kzalloc(dev, sizeof(*dfluart), GFP_KERNEL); > + if (!dfluart) > + return -ENOMEM; > + > + dfh_base = devm_ioremap_resource(dev, &dfl_dev->mmio_res); > + if (IS_ERR(dfh_base)) > + return PTR_ERR(dfh_base); > + > + res_size = resource_size(&dfl_dev->mmio_res); > + > + ret = dfl_uart_get_params(dev, dfh_base, res_size, &uart); > + > + devm_iounmap(dev, dfh_base); > + devm_release_mem_region(dev, dfl_dev->mmio_res.start, res_size); > + > + if (ret < 0) > + return dev_err_probe(dev, ret, "failed uart feature walk\n"); > + > + dev_dbg(dev, "nr_irqs %d %p\n", dfl_dev->num_irqs, dfl_dev->irqs); > + > + if (dfl_dev->num_irqs == 1) > + uart.port.irq = dfl_dev->irqs[0]; > + > + /* register the port */ This comment is pretty useless. Just drop it. > + dfluart->line = serial8250_register_8250_port(&uart); > + if (dfluart->line < 0) > + return dev_err_probe(dev, dfluart->line, "unable to register 8250 port.\n"); > + > + dev_info(dev, "serial8250_register_8250_port %d\n", dfluart->line); This you want to drop too. It seems a debug thing rather than info level stuff. -- i.