From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932827AbdBHA65 (ORCPT ); Tue, 7 Feb 2017 19:58:57 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:32854 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932122AbdBHA6t (ORCPT ); Tue, 7 Feb 2017 19:58:49 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 611A5609FD Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=cov@codeaurora.org From: Christopher Covington To: Jonathan Corbet , Marc Zyngier , Catalin Marinas , Will Deacon , linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Rutland , linux-kernel@vger.kernel.org, shankerd@codeaurora.org, timur@codeaurora.org, Russell King , Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org Cc: Mark Langsdorf , Mark Salter , Jon Masters , Neil Leeder , Christopher Covington Subject: [PATCH 2/2] tty: pl011: Work around QDF2400 E44 for earlycon Date: Tue, 7 Feb 2017 19:57:36 -0500 Message-Id: <20170208005736.18724-2-cov@codeaurora.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170208005736.18724-1-cov@codeaurora.org> References: <20170208005736.18724-1-cov@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The previous change worked around QDF2432v1 and QDF2400v1 SoC erratum 44 for the full-fledged console, when UART AMBA Port (UAP) data is available. Additionally provide a workaround the earlycon case, again checking TXFE == 0 instead of BUSY == 1. As earlycon is operating before UAP data is available, the implementation is different than in the preceding patch. Signed-off-by: Christopher Covington --- drivers/tty/serial/amba-pl011.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 41e51901d6ef..f25e7c994f8e 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2411,6 +2411,29 @@ static bool qdf2400_e44(void) { cpu_var_model == MIDR_QCOM_FALKOR_V1); } +#ifdef CONFIG_QCOM_QDF2400_ERRATUM_44 +static void qdf2400_e44_putc(struct uart_port *port, int c) +{ + while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF) + cpu_relax(); + if (port->iotype == UPIO_MEM32) + writel(c, port->membase + UART01x_DR); + else + writeb(c, port->membase + UART01x_DR); + while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE)) + cpu_relax(); +} + +static void qdf2400_e44_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, qdf2400_e44_putc); +} +#else +#define qdf2400_e44_early_write pl011_early_write +#endif + static void pl011_putc(struct uart_port *port, int c) { while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF) @@ -2436,7 +2459,10 @@ static int __init pl011_early_console_setup(struct earlycon_device *device, if (!device->port.membase) return -ENODEV; - device->con->write = pl011_early_write; + if (qdf2400_e44()) + device->con->write = qdf2400_e44_early_write; + else + device->con->write = pl011_early_write; return 0; } OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup); -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.