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 35940C636D4 for ; Fri, 10 Feb 2023 15:52:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232371AbjBJPwY (ORCPT ); Fri, 10 Feb 2023 10:52:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231954AbjBJPwX (ORCPT ); Fri, 10 Feb 2023 10:52:23 -0500 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB67C4B749; Fri, 10 Feb 2023 07:52:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676044342; x=1707580342; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=qUpgAiH+JCVRIJKren1kim03Bn8BaV6Vy8ou499xSOc=; b=QmXyHh7ka/PsizH71W+NacxwD1euGyqw/cXAlX+DoopjdzRdhGv/rRPp 92wv13ilfiA64JllA1GqI5yt9Ox4r/Dob5CUIyY/ek7pWzzR1IT4iU6yI tF/YmHX5SShfNF+IFiZyyv/fVo/WSI3FIakVQgnTWkuKDtiv59v3H08Si gKT90gwe885+rc/ROF6UFzDumAcvCA7sCuHA2oGZW1F0Wjr+YrVbpjBFV 77hm5xL0MPdr6xZgnhawhfXZ0JeeijwG7ylOIIhdFUfsSR9tR7lvQCIZg NqPu8or1e2Iz5AuLtd34JDUaKFl/Gwn6iyhNs2uaQsFLzS+QJzvut06hX Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10617"; a="329077800" X-IronPort-AV: E=Sophos;i="5.97,287,1669104000"; d="scan'208";a="329077800" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2023 07:52:22 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10617"; a="668094427" X-IronPort-AV: E=Sophos;i="5.97,287,1669104000"; d="scan'208";a="668094427" Received: from tnemeth-mobl1.ger.corp.intel.com ([10.251.213.60]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2023 07:52:19 -0800 Date: Fri, 10 Feb 2023 17:52:17 +0200 (EET) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: Biju Das cc: Greg Kroah-Hartman , Jiri Slaby , linux-serial , Geert Uytterhoeven , Fabrizio Castro , linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH v2 3/3] serial: 8250_em: Add serial_out() to struct serial8250_em_hw_info In-Reply-To: <20230210154140.338352-4-biju.das.jz@bp.renesas.com> Message-ID: <954bb490-b516-6624-5bb9-e82434fc95f0@linux.intel.com> References: <20230210154140.338352-1-biju.das.jz@bp.renesas.com> <20230210154140.338352-4-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Fri, 10 Feb 2023, Biju Das wrote: > As per HW manual section 40.6.1, we need to perform FIFO reset + SW > reset before updating the below registers. > > FCR[7:5], FCR[3:0], LCR[7][5:0], MCR[6:4], DLL[7:0], DLM[7:0] and > HCR0[6:5][3:2]. > > This patch adds serial_out() to struct serial8250_em_hw_info to > handle this difference between emma mobile and rz/v2m. > > DLL/DLM register can be updated only by setting LCR[7]. So the > updation of LCR[7] will perform reset for DLL/DLM register changes. > > Signed-off-by: Biju Das > --- > v1->v2: > * Added serial_out to struct serial8250_em_hw_info Thanks, this looks much better. One additional comment below. > --- > drivers/tty/serial/8250/8250_em.c | 59 ++++++++++++++++++++++++++++++- > 1 file changed, 58 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c > index 628a6846bfdc..1816362a3a3a 100644 > --- a/drivers/tty/serial/8250/8250_em.c > +++ b/drivers/tty/serial/8250/8250_em.c > @@ -19,10 +19,14 @@ > > #define UART_DLL_EM 9 > #define UART_DLM_EM 10 > +#define UART_HCR0 11 > + > +#define UART_HCR0_SW_RESET BIT(7) /* SW Reset */ > > struct serial8250_em_hw_info { > unsigned int type; > upf_t flags; > + void (*serial_out)(struct uart_port *p, int off, int value); > }; > > struct serial8250_em_priv { > @@ -31,6 +35,40 @@ struct serial8250_em_priv { > const struct serial8250_em_hw_info *info; > }; > > +static void serial8250_rzv2m_reg_update(struct uart_port *p, int off, int value) > +{ > + unsigned int ier, fcr, lcr, mcr, hcr0; > + > + ier = readl(p->membase + (UART_IER << 2)); > + hcr0 = readl(p->membase + (UART_HCR0 << 2)); > + fcr = readl(p->membase + ((UART_FCR + 1) << 2)); > + lcr = readl(p->membase + ((UART_LCR + 1) << 2)); > + mcr = readl(p->membase + ((UART_MCR + 1) << 2)); > + > + writel(fcr | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, > + p->membase + ((UART_FCR + 1) << 2)); > + writel(hcr0 | UART_HCR0_SW_RESET, p->membase + (UART_HCR0 << 2)); > + writel(hcr0 & ~UART_HCR0_SW_RESET, p->membase + (UART_HCR0 << 2)); > + > + switch (off) { > + case UART_FCR: > + fcr = value; > + break; > + case UART_LCR: > + lcr = value; > + break; > + case UART_MCR: > + mcr = value; > + break; > + } > + > + writel(ier, p->membase + (UART_IER << 2)); > + writel(fcr, p->membase + ((UART_FCR + 1) << 2)); > + writel(mcr, p->membase + ((UART_MCR + 1) << 2)); > + writel(lcr, p->membase + ((UART_LCR + 1) << 2)); > + writel(hcr0, p->membase + (UART_HCR0 << 2)); Perhaps it would make sense to instead of using readl/writel() directly to call serial8250_em_serial_in/out() so all the offset trickery wouldn't need to be duplicated inside this function? -- i. > +} > + > static void serial8250_em_serial_out(struct uart_port *p, int offset, int value) > { > switch (offset) { > @@ -52,6 +90,23 @@ static void serial8250_em_serial_out(struct uart_port *p, int offset, int value) > } > } > > +static void serial8250_em_rzv2m_serial_out(struct uart_port *p, int offset, int value) > +{ > + switch (offset) { > + case UART_TX: > + case UART_SCR: > + case UART_IER: > + case UART_DLL_EM: > + case UART_DLM_EM: > + serial8250_em_serial_out(p, offset, value); > + break; > + case UART_FCR: > + case UART_LCR: > + case UART_MCR: > + serial8250_rzv2m_reg_update(p, offset, value); > + } > +} > + > static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset) > { > switch (offset) { > @@ -119,7 +174,7 @@ static int serial8250_em_probe(struct platform_device *pdev) > > up.port.iotype = UPIO_MEM32; > up.port.serial_in = serial8250_em_serial_in; > - up.port.serial_out = serial8250_em_serial_out; > + up.port.serial_out = priv->info->serial_out; > up.dl_read = serial8250_em_serial_dl_read; > up.dl_write = serial8250_em_serial_dl_write; > > @@ -144,11 +199,13 @@ static int serial8250_em_remove(struct platform_device *pdev) > static const struct serial8250_em_hw_info emma_mobile_uart_hw_info = { > .type = PORT_UNKNOWN, > .flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP, > + .serial_out = serial8250_em_serial_out, > }; > > static const struct serial8250_em_hw_info rzv2m_uart_hw_info = { > .type = PORT_16750, > .flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP | UPF_FIXED_TYPE, > + .serial_out = serial8250_em_rzv2m_serial_out, > }; > > static const struct of_device_id serial8250_em_dt_ids[] = { >