From patchwork Thu Mar 4 21:38:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 393758 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C25FC43332 for ; Thu, 4 Mar 2021 21:43:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E72CA64F80 for ; Thu, 4 Mar 2021 21:43:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240830AbhCDVnD (ORCPT ); Thu, 4 Mar 2021 16:43:03 -0500 Received: from marcansoft.com ([212.63.210.85]:34802 "EHLO mail.marcansoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240788AbhCDVnA (ORCPT ); Thu, 4 Mar 2021 16:43:00 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id 5B5B84270F; Thu, 4 Mar 2021 21:42:11 +0000 (UTC) From: Hector Martin To: linux-arm-kernel@lists.infradead.org Cc: Hector Martin , Marc Zyngier , Rob Herring , Arnd Bergmann , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , Mark Rutland , Andy Shevchenko , Greg Kroah-Hartman , Jonathan Corbet , Catalin Marinas , Christoph Hellwig , "David S. Miller" , devicetree@vger.kernel.org, linux-serial@vger.kernel.org, linux-doc@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFT PATCH v3 24/27] tty: serial: samsung_tty: Add support for Apple UARTs Date: Fri, 5 Mar 2021 06:38:59 +0900 Message-Id: <20210304213902.83903-25-marcan@marcan.st> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210304213902.83903-1-marcan@marcan.st> References: <20210304213902.83903-1-marcan@marcan.st> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Apple SoCs are a distant descendant of Samsung designs and use yet another variant of their UART style, with different interrupt handling. In particular, this variant has the following differences with existing ones: * It includes a built-in interrupt controller with different registers, using only a single platform IRQ * Internal interrupt sources are treated as edge-triggered, even though the IRQ output is level-triggered. This chiefly affects the TX IRQ path: the driver can no longer rely on the TX buffer empty IRQ immediately firing after TX is enabled, but instead must prime the FIFO with data directly. Signed-off-by: Hector Martin Reviewed-by: Krzysztof Kozlowski Tested-by: Krzysztof Kozlowski --- drivers/tty/serial/Kconfig | 2 +- drivers/tty/serial/samsung_tty.c | 238 +++++++++++++++++++++++++++++-- include/linux/serial_s3c.h | 16 +++ 3 files changed, 247 insertions(+), 9 deletions(-) diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 0c4cd4a348f4..3ba31ea20d8a 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -236,7 +236,7 @@ config SERIAL_CLPS711X_CONSOLE config SERIAL_SAMSUNG tristate "Samsung SoC serial support" - depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST + depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_APPLE || COMPILE_TEST select SERIAL_CORE help Support for the on-chip UARTs on the Samsung S3C24XX series CPUs, diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 26cb05992e9f..5ef37c4538ce 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -59,6 +59,7 @@ enum s3c24xx_port_type { TYPE_S3C24XX, TYPE_S3C6400, + TYPE_APPLE_S5L, }; struct s3c24xx_uart_info { @@ -151,6 +152,8 @@ struct s3c24xx_uart_port { #endif }; +static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport); + /* conversion functions */ #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev) @@ -290,6 +293,9 @@ static void s3c24xx_serial_stop_tx(struct uart_port *port) case TYPE_S3C6400: s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM); break; + case TYPE_APPLE_S5L: + s3c24xx_clear_bit(port, APPLE_S5L_UCON_TXTHRESH_ENA, S3C2410_UCON); + break; default: disable_irq_nosync(ourport->tx_irq); break; @@ -358,6 +364,9 @@ static void enable_tx_dma(struct s3c24xx_uart_port *ourport) case TYPE_S3C6400: s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM); break; + case TYPE_APPLE_S5L: + WARN_ON(1); // No DMA + break; default: disable_irq_nosync(ourport->tx_irq); break; @@ -396,12 +405,23 @@ static void enable_tx_pio(struct s3c24xx_uart_port *ourport) s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM); break; + case TYPE_APPLE_S5L: + ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK; + wr_regl(port, S3C2410_UCON, ucon); + break; default: enable_irq(ourport->tx_irq); break; } ourport->tx_mode = S3C24XX_TX_PIO; + + /* + * The Apple version only has edge triggered TX IRQs, so we need + * to kick off the process by sending some characters here. + */ + if (ourport->info->type == TYPE_APPLE_S5L) + s3c24xx_serial_tx_chars(ourport); } static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport) @@ -527,6 +547,10 @@ static void s3c24xx_serial_stop_rx(struct uart_port *port) s3c24xx_set_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM); break; + case TYPE_APPLE_S5L: + s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON); + s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON); + break; default: disable_irq_nosync(ourport->rx_irq); break; @@ -664,14 +688,18 @@ static void enable_rx_pio(struct s3c24xx_uart_port *ourport) /* set Rx mode to DMA mode */ ucon = rd_regl(port, S3C2410_UCON); - ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK | - S3C64XX_UCON_EMPTYINT_EN | - S3C64XX_UCON_DMASUS_EN | - S3C64XX_UCON_TIMEOUT_EN | - S3C64XX_UCON_RXMODE_MASK); - ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT | - S3C64XX_UCON_TIMEOUT_EN | - S3C64XX_UCON_RXMODE_CPU; + ucon &= ~S3C64XX_UCON_RXMODE_MASK; + ucon |= S3C64XX_UCON_RXMODE_CPU; + + /* Apple types use these bits for IRQ masks */ + if (ourport->info->type != TYPE_APPLE_S5L) { + ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK | + S3C64XX_UCON_EMPTYINT_EN | + S3C64XX_UCON_DMASUS_EN | + S3C64XX_UCON_TIMEOUT_EN); + ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT | + S3C64XX_UCON_TIMEOUT_EN; + } wr_regl(port, S3C2410_UCON, ucon); ourport->rx_mode = S3C24XX_RX_PIO; @@ -935,6 +963,27 @@ static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id) return ret; } +/* interrupt handler for Apple SoC's.*/ +static irqreturn_t apple_serial_handle_irq(int irq, void *id) +{ + struct s3c24xx_uart_port *ourport = id; + struct uart_port *port = &ourport->port; + unsigned int pend = rd_regl(port, S3C2410_UTRSTAT); + irqreturn_t ret = IRQ_NONE; + + if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) { + wr_regl(port, S3C2410_UTRSTAT, + APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO); + ret = s3c24xx_serial_rx_irq(irq, id); + } + if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) { + wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH); + ret = s3c24xx_serial_tx_irq(irq, id); + } + + return ret; +} + static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port) { struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port); @@ -1154,6 +1203,32 @@ static void s3c64xx_serial_shutdown(struct uart_port *port) ourport->tx_in_progress = 0; } +static void apple_s5l_serial_shutdown(struct uart_port *port) +{ + struct s3c24xx_uart_port *ourport = to_ourport(port); + + unsigned int ucon; + + ucon = rd_regl(port, S3C2410_UCON); + ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK | + APPLE_S5L_UCON_RXTHRESH_ENA_MSK | + APPLE_S5L_UCON_RXTO_ENA_MSK); + wr_regl(port, S3C2410_UCON, ucon); + + wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS); + + free_irq(port->irq, ourport); + + ourport->tx_enabled = 0; + ourport->tx_mode = 0; + ourport->rx_enabled = 0; + + if (ourport->dma) + s3c24xx_serial_release_dma(ourport); + + ourport->tx_in_progress = 0; +} + static int s3c24xx_serial_startup(struct uart_port *port) { struct s3c24xx_uart_port *ourport = to_ourport(port); @@ -1241,6 +1316,45 @@ static int s3c64xx_serial_startup(struct uart_port *port) return ret; } +static int apple_s5l_serial_startup(struct uart_port *port) +{ + struct s3c24xx_uart_port *ourport = to_ourport(port); + unsigned long flags; + unsigned int ufcon; + int ret; + + wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS); + + ret = request_irq(port->irq, apple_serial_handle_irq, 0, + s3c24xx_serial_portname(port), ourport); + if (ret) { + dev_err(port->dev, "cannot get irq %d\n", port->irq); + return ret; + } + + /* For compatibility with s3c24xx Soc's */ + ourport->rx_enabled = 1; + ourport->tx_enabled = 0; + + spin_lock_irqsave(&port->lock, flags); + + ufcon = rd_regl(port, S3C2410_UFCON); + ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8; + if (!uart_console(port)) + ufcon |= S3C2410_UFCON_RESETTX; + wr_regl(port, S3C2410_UFCON, ufcon); + + enable_rx_pio(ourport); + + spin_unlock_irqrestore(&port->lock, flags); + + /* Enable Rx Interrupt */ + s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON); + s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON); + + return ret; +} + /* power power management control */ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, @@ -1568,6 +1682,8 @@ static const char *s3c24xx_serial_type(struct uart_port *port) return "S3C24XX"; case TYPE_S3C6400: return "S3C6400/10"; + case TYPE_APPLE_S5L: + return "APPLE S5L"; default: return NULL; } @@ -1659,6 +1775,27 @@ static const struct uart_ops s3c64xx_serial_ops = { #endif }; +static const struct uart_ops apple_s5l_serial_ops = { + .pm = s3c24xx_serial_pm, + .tx_empty = s3c24xx_serial_tx_empty, + .get_mctrl = s3c24xx_serial_get_mctrl, + .set_mctrl = s3c24xx_serial_set_mctrl, + .stop_tx = s3c24xx_serial_stop_tx, + .start_tx = s3c24xx_serial_start_tx, + .stop_rx = s3c24xx_serial_stop_rx, + .break_ctl = s3c24xx_serial_break_ctl, + .startup = apple_s5l_serial_startup, + .shutdown = apple_s5l_serial_shutdown, + .set_termios = s3c24xx_serial_set_termios, + .type = s3c24xx_serial_type, + .config_port = s3c24xx_serial_config_port, + .verify_port = s3c24xx_serial_verify_port, +#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL) + .poll_get_char = s3c24xx_serial_get_poll_char, + .poll_put_char = s3c24xx_serial_put_poll_char, +#endif +}; + static struct uart_driver s3c24xx_uart_drv = { .owner = THIS_MODULE, .driver_name = "s3c2410_serial", @@ -1975,6 +2112,18 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport, wr_regl(port, S3C64XX_UINTP, 0xf); wr_regl(port, S3C64XX_UINTSP, 0xf); break; + case TYPE_APPLE_S5L: { + unsigned int ucon; + + ucon = rd_regl(port, S3C2410_UCON); + ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK | + APPLE_S5L_UCON_RXTHRESH_ENA_MSK | + APPLE_S5L_UCON_RXTO_ENA_MSK); + wr_regl(port, S3C2410_UCON, ucon); + + wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS); + break; + } default: break; } @@ -2054,6 +2203,9 @@ static int s3c24xx_serial_probe(struct platform_device *pdev) case TYPE_S3C6400: ourport->port.ops = &s3c64xx_serial_ops; break; + case TYPE_APPLE_S5L: + ourport->port.ops = &apple_s5l_serial_ops; + break; } if (np) { @@ -2196,6 +2348,43 @@ static int s3c24xx_serial_resume_noirq(struct device *dev) clk_disable_unprepare(ourport->clk); break; } + case TYPE_APPLE_S5L: { + unsigned int ucon; + int ret; + + ret = clk_prepare_enable(ourport->clk); + if (ret) { + dev_err(dev, "clk_enable clk failed: %d\n", ret); + return ret; + } + if (!IS_ERR(ourport->baudclk)) { + ret = clk_prepare_enable(ourport->baudclk); + if (ret) { + dev_err(dev, "clk_enable baudclk failed: %d\n", ret); + clk_disable_unprepare(ourport->clk); + return ret; + } + } + + ucon = rd_regl(port, S3C2410_UCON); + + ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK | + APPLE_S5L_UCON_RXTHRESH_ENA_MSK | + APPLE_S5L_UCON_RXTO_ENA_MSK); + + if (ourport->tx_enabled) + ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK; + if (ourport->rx_enabled) + ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK | + APPLE_S5L_UCON_RXTO_ENA_MSK; + + wr_regl(port, S3C2410_UCON, ucon); + + if (!IS_ERR(ourport->baudclk)) + clk_disable_unprepare(ourport->baudclk); + clk_disable_unprepare(ourport->clk); + break; + } default: break; } @@ -2605,6 +2794,34 @@ static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = { #define EXYNOS5433_SERIAL_DRV_DATA (kernel_ulong_t)NULL #endif +#ifdef CONFIG_ARCH_APPLE +static struct s3c24xx_serial_drv_data s5l_serial_drv_data = { + .info = &(struct s3c24xx_uart_info) { + .name = "Apple S5L UART", + .type = TYPE_APPLE_S5L, + .port_type = PORT_8250, + .fifosize = 16, + .rx_fifomask = S3C2410_UFSTAT_RXMASK, + .rx_fifoshift = S3C2410_UFSTAT_RXSHIFT, + .rx_fifofull = S3C2410_UFSTAT_RXFULL, + .tx_fifofull = S3C2410_UFSTAT_TXFULL, + .tx_fifomask = S3C2410_UFSTAT_TXMASK, + .tx_fifoshift = S3C2410_UFSTAT_TXSHIFT, + .def_clk_sel = S3C2410_UCON_CLKSEL0, + .num_clks = 1, + .clksel_mask = 0, + .clksel_shift = 0, + }, + .def_cfg = &(struct s3c2410_uartcfg) { + .ucon = APPLE_S5L_UCON_DEFAULT, + .ufcon = S3C2410_UFCON_DEFAULT, + }, +}; +#define S5L_SERIAL_DRV_DATA ((kernel_ulong_t)&s5l_serial_drv_data) +#else +#define S5L_SERIAL_DRV_DATA ((kernel_ulong_t)NULL) +#endif + static const struct platform_device_id s3c24xx_serial_driver_ids[] = { { .name = "s3c2410-uart", @@ -2627,6 +2844,9 @@ static const struct platform_device_id s3c24xx_serial_driver_ids[] = { }, { .name = "exynos5433-uart", .driver_data = EXYNOS5433_SERIAL_DRV_DATA, + }, { + .name = "s5l-uart", + .driver_data = S5L_SERIAL_DRV_DATA, }, { }, }; @@ -2648,6 +2868,8 @@ static const struct of_device_id s3c24xx_uart_dt_match[] = { .data = (void *)EXYNOS4210_SERIAL_DRV_DATA }, { .compatible = "samsung,exynos5433-uart", .data = (void *)EXYNOS5433_SERIAL_DRV_DATA }, + { .compatible = "apple,s5l-uart", + .data = (void *)S5L_SERIAL_DRV_DATA }, {}, }; MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match); diff --git a/include/linux/serial_s3c.h b/include/linux/serial_s3c.h index ca2c5393dc6b..f6c3323fc4c5 100644 --- a/include/linux/serial_s3c.h +++ b/include/linux/serial_s3c.h @@ -246,6 +246,22 @@ S5PV210_UFCON_TXTRIG4 | \ S5PV210_UFCON_RXTRIG4) +#define APPLE_S5L_UCON_RXTO_ENA 9 +#define APPLE_S5L_UCON_RXTHRESH_ENA 12 +#define APPLE_S5L_UCON_TXTHRESH_ENA 13 +#define APPLE_S5L_UCON_RXTO_ENA_MSK (1 << APPLE_S5L_UCON_RXTO_ENA) +#define APPLE_S5L_UCON_RXTHRESH_ENA_MSK (1 << APPLE_S5L_UCON_RXTHRESH_ENA) +#define APPLE_S5L_UCON_TXTHRESH_ENA_MSK (1 << APPLE_S5L_UCON_TXTHRESH_ENA) + +#define APPLE_S5L_UCON_DEFAULT (S3C2410_UCON_TXIRQMODE | \ + S3C2410_UCON_RXIRQMODE | \ + S3C2410_UCON_RXFIFO_TOI) + +#define APPLE_S5L_UTRSTAT_RXTHRESH (1<<4) +#define APPLE_S5L_UTRSTAT_TXTHRESH (1<<5) +#define APPLE_S5L_UTRSTAT_RXTO (1<<9) +#define APPLE_S5L_UTRSTAT_ALL_FLAGS (0x3f0) + #ifndef __ASSEMBLY__ #include