From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EA9E72D903A; Mon, 5 May 2025 22:51:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746485510; cv=none; b=DL/yQf7DfzCd/AZZm5METNCnMu4bB4h9FAqvoJQvM1na4LwZOOXPOpSOGdeBzDDC2hP3dgML+92v8U19KfIPHXswMlQxlb7/TCXx2QBHaHnpf/kQ9rXyWj3VTzO3Rhmbz/uscKVlto3sYFJ2AFt/T+5mlU8g0fE04BzKuKiWdxc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746485510; c=relaxed/simple; bh=L6D9xzoCd0UnYBZlHB7c9sOjUCs838NdruQURRT1GHc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aP50wV3PRgtkDpZBAzAZW9530CuHBqTrAnpKfHYIwxirFmTaeWLaBqGDNiCz91AW/VvmqOfyGYteXP7aTpzYo6rA66j9GUEZ81sgnPIiZgzV3Nm/h0bWxK5BftGhEraMbELtvQ2GhmWHTZvT7Tbwshe/xy0UPt5DjolftwhBthU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KpK+a+V7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KpK+a+V7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F950C4CEE4; Mon, 5 May 2025 22:51:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746485509; bh=L6D9xzoCd0UnYBZlHB7c9sOjUCs838NdruQURRT1GHc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KpK+a+V75Q6xPXb/cPRRVQZcPXzIrccHXceFTod+JAqqE2R/dwE3SMxYKgwrL/lTj MR9tyscBNCeLUfcizVhYyxAhNEYONSvjnpdXefwFsHYZTqatYg7EXtqgI14fgt2K5N RFQYHctQBrqBbt8tJsftsQZgGo7R4S+WadSNrVxNs6CA/x0JPmlKge0WxecFZ1xV95 vkP0coutb+R2iKJikI96R7WnOArObbmbE+vSrwJjAV8GGS7CzlMgZanvQBgl+OZ5Qp iichhs88WEC5cnGytbkhMxwuqVkCo/KLE/iLDq2jORUpsvd60lkcHJ3qKkAeMJFiYW 8AVUbUM2YTB1g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Claudiu Beznea , Geert Uytterhoeven , Greg Kroah-Hartman , Sasha Levin , jirislaby@kernel.org, p.zabel@pengutronix.de, wsa+renesas@sang-engineering.com, prabhakar.mahadev-lad.rj@bp.renesas.com, namcao@linutronix.de, linux-serial@vger.kernel.org Subject: [PATCH AUTOSEL 6.12 352/486] serial: sh-sci: Update the suspend/resume support Date: Mon, 5 May 2025 18:37:08 -0400 Message-Id: <20250505223922.2682012-352-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505223922.2682012-1-sashal@kernel.org> References: <20250505223922.2682012-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.26 Content-Transfer-Encoding: 8bit From: Claudiu Beznea [ Upstream commit 22a6984c5b5df8eab864d7f3e8b94d5a554d31ab ] The Renesas RZ/G3S supports a power saving mode where power to most of the SoC components is turned off. When returning from this power saving mode, SoC components need to be re-configured. The SCIFs on the Renesas RZ/G3S need to be re-configured as well when returning from this power saving mode. The sh-sci code already configures the SCIF clocks, power domain and registers by calling uart_resume_port() in sci_resume(). On suspend path the SCIF UART ports are suspended accordingly (by calling uart_suspend_port() in sci_suspend()). The only missing setting is the reset signal. For this assert/de-assert the reset signal on driver suspend/resume. In case the no_console_suspend is specified by the user, the registers need to be saved on suspend path and restore on resume path. To do this the sci_console_save()/sci_console_restore() functions were added. There is no need to cache/restore the status or FIFO registers. Only the control registers. The registers that will be saved/restored on suspend/resume are specified by the struct sci_suspend_regs data structure. Signed-off-by: Claudiu Beznea Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20250207113313.545432-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/sh-sci.c | 71 +++++++++++++++++++++++++++++++++++-- 1 file changed, 69 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 80efe3b0ed0c3..779074b1c2be4 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -104,6 +104,15 @@ struct plat_sci_reg { u8 offset, size; }; +struct sci_suspend_regs { + u16 scsmr; + u16 scscr; + u16 scfcr; + u16 scsptr; + u8 scbrr; + u8 semr; +}; + struct sci_port_params { const struct plat_sci_reg regs[SCIx_NR_REGS]; unsigned int fifosize; @@ -134,6 +143,8 @@ struct sci_port { struct dma_chan *chan_tx; struct dma_chan *chan_rx; + struct reset_control *rstc; + #ifdef CONFIG_SERIAL_SH_SCI_DMA struct dma_chan *chan_tx_saved; struct dma_chan *chan_rx_saved; @@ -153,6 +164,7 @@ struct sci_port { int rx_trigger; struct timer_list rx_fifo_timer; int rx_fifo_timeout; + struct sci_suspend_regs suspend_regs; u16 hscif_tot; bool has_rtscts; @@ -3384,6 +3396,7 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev, } sp = &sci_ports[id]; + sp->rstc = rstc; *dev_id = id; p->type = SCI_OF_TYPE(data); @@ -3532,13 +3545,57 @@ static int sci_probe(struct platform_device *dev) return 0; } +static void sci_console_save(struct sci_port *s) +{ + struct sci_suspend_regs *regs = &s->suspend_regs; + struct uart_port *port = &s->port; + + if (sci_getreg(port, SCSMR)->size) + regs->scsmr = sci_serial_in(port, SCSMR); + if (sci_getreg(port, SCSCR)->size) + regs->scscr = sci_serial_in(port, SCSCR); + if (sci_getreg(port, SCFCR)->size) + regs->scfcr = sci_serial_in(port, SCFCR); + if (sci_getreg(port, SCSPTR)->size) + regs->scsptr = sci_serial_in(port, SCSPTR); + if (sci_getreg(port, SCBRR)->size) + regs->scbrr = sci_serial_in(port, SCBRR); + if (sci_getreg(port, SEMR)->size) + regs->semr = sci_serial_in(port, SEMR); +} + +static void sci_console_restore(struct sci_port *s) +{ + struct sci_suspend_regs *regs = &s->suspend_regs; + struct uart_port *port = &s->port; + + if (sci_getreg(port, SCSMR)->size) + sci_serial_out(port, SCSMR, regs->scsmr); + if (sci_getreg(port, SCSCR)->size) + sci_serial_out(port, SCSCR, regs->scscr); + if (sci_getreg(port, SCFCR)->size) + sci_serial_out(port, SCFCR, regs->scfcr); + if (sci_getreg(port, SCSPTR)->size) + sci_serial_out(port, SCSPTR, regs->scsptr); + if (sci_getreg(port, SCBRR)->size) + sci_serial_out(port, SCBRR, regs->scbrr); + if (sci_getreg(port, SEMR)->size) + sci_serial_out(port, SEMR, regs->semr); +} + static __maybe_unused int sci_suspend(struct device *dev) { struct sci_port *sport = dev_get_drvdata(dev); - if (sport) + if (sport) { uart_suspend_port(&sci_uart_driver, &sport->port); + if (!console_suspend_enabled && uart_console(&sport->port)) + sci_console_save(sport); + else + return reset_control_assert(sport->rstc); + } + return 0; } @@ -3546,8 +3603,18 @@ static __maybe_unused int sci_resume(struct device *dev) { struct sci_port *sport = dev_get_drvdata(dev); - if (sport) + if (sport) { + if (!console_suspend_enabled && uart_console(&sport->port)) { + sci_console_restore(sport); + } else { + int ret = reset_control_deassert(sport->rstc); + + if (ret) + return ret; + } + uart_resume_port(&sci_uart_driver, &sport->port); + } return 0; } -- 2.39.5