From patchwork Mon Apr 22 12:37:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Konstantin Pugin X-Patchwork-Id: 792255 Received: from forward501c.mail.yandex.net (forward501c.mail.yandex.net [178.154.239.209]) (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 C202C14A61A; Mon, 22 Apr 2024 12:45:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.209 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713789932; cv=none; b=HO3MUfMX1jsAPfH5UXOJlnms2SPxKEKT7odKgor1CjF3f3jq953jIq4ycGlVsgJau10Cj/QAWZ6RRUx3L/O5hs/MDBNJCoot1UY1vYJwJ1HDafbqe14JYqSBphBaq0OQsJjcpuqCAgcc+5UCGnyDrz+Z0CYHohQlbGzYsxGAsuw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713789932; c=relaxed/simple; bh=r3USCwhaeDAaO8vM5iT17mfuUPZhjlL7CZ8LW7Vc22w=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Lybcwe5KYdDquqJwuQ08gpM97A4odBzbx77W+bg8ABRWoeFBI5pibeBoKjseo9BWYyCNa3agRE/MHAVPfPQsro+N0DmdgP7m1jy1OMOrkBF404XuOl3BXMhHl5qv6HIKaW+lPS1Z8CGz8jDzqOq086rFqepqyJUluGiOYcDKxQs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ya.ru; spf=pass smtp.mailfrom=ya.ru; dkim=pass (1024-bit key) header.d=ya.ru header.i=@ya.ru header.b=C7PQjSGS; arc=none smtp.client-ip=178.154.239.209 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ya.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ya.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ya.ru header.i=@ya.ru header.b="C7PQjSGS" Received: from mail-nwsmtp-smtp-production-main-81.myt.yp-c.yandex.net (mail-nwsmtp-smtp-production-main-81.myt.yp-c.yandex.net [IPv6:2a02:6b8:c12:3729:0:640:85f7:0]) by forward501c.mail.yandex.net (Yandex) with ESMTPS id 17CED6107C; Mon, 22 Apr 2024 15:38:36 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-81.myt.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id 6cIEH34oJ8c0-D5tiB4cm; Mon, 22 Apr 2024 15:38:34 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ya.ru; s=mail; t=1713789514; bh=/bzELXHdxbBKlA4ePuJg/gLgwkqBTSnkJ1/BpBYlKJ4=; h=Message-Id:Date:In-Reply-To:Cc:Subject:References:To:From; b=C7PQjSGSQ6qWN20DwnMHlR+RJYtjFHk6v2ZZ4S92PPncD2qw81vKrBpTOF4pfyYbD HQBHyShOfZiXbAaLEvEmMegOK/U3XsmTQyIbJrkm+Q4/ZNr16OSdzMjh901AqeTIYP /4JMeuzcY0lp0t5MelNjkeLoGDsMayI37lIJdB8I= Authentication-Results: mail-nwsmtp-smtp-production-main-81.myt.yp-c.yandex.net; dkim=pass header.i=@ya.ru From: Konstantin Pugin To: Cc: krzk@kernel.org, conor@kernel.org, lkp@intel.com, vz@mleia.com, robh@kernel.org, jcmvbkbc@gmail.com, nicolas.ferre@microchip.com, manikanta.guntupalli@amd.com, corbet@lwn.net, ychuang3@nuvoton.com, u.kleine-koenig@pengutronix.de, Maarten.Brock@sttls.nl, Konstantin Pugin , Greg Kroah-Hartman , Jiri Slaby , Andy Shevchenko , Jernej Skrabec , Hugo Villeneuve , Anup Patel , Lech Perczak , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH v6 3/3] serial: sc16is7xx: add support for EXAR XR20M1172 UART Date: Mon, 22 Apr 2024 15:37:57 +0300 Message-Id: <20240422123801.2695129-4-rilian.la.te@ya.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240422123801.2695129-1-rilian.la.te@ya.ru> References: <20240422123801.2695129-1-rilian.la.te@ya.ru> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Konstantin Pugin XR20M1172 register set is mostly compatible with SC16IS762, but it has a support for additional division rates of UART with special DLD register. So, add handling this register by appropriate devicetree bindings. Signed-off-by: Konstantin Pugin --- drivers/tty/serial/Kconfig | 3 +- drivers/tty/serial/sc16is7xx.c | 61 ++++++++++++++++++++++++++++-- drivers/tty/serial/sc16is7xx_i2c.c | 1 + drivers/tty/serial/sc16is7xx_spi.c | 1 + 4 files changed, 61 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 4fdd7857ef4d..9d0438cfe147 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1029,7 +1029,7 @@ config SERIAL_SC16IS7XX_CORE select SERIAL_SC16IS7XX_SPI if SPI_MASTER select SERIAL_SC16IS7XX_I2C if I2C help - Core driver for NXP SC16IS7xx UARTs. + Core driver for NXP SC16IS7xx and compatible UARTs. Supported ICs are: SC16IS740 @@ -1038,6 +1038,7 @@ config SERIAL_SC16IS7XX_CORE SC16IS752 SC16IS760 SC16IS762 + XR20M1172 (Exar) The driver supports both I2C and SPI interfaces. diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index dfcc804f558f..504a6b9ca3ba 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -10,6 +10,7 @@ #undef DEFAULT_SYMBOL_NAMESPACE #define DEFAULT_SYMBOL_NAMESPACE SERIAL_NXP_SC16IS7XX +#include #include #include #include @@ -68,6 +69,7 @@ /* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */ #define SC16IS7XX_DLL_REG (0x00) /* Divisor Latch Low */ #define SC16IS7XX_DLH_REG (0x01) /* Divisor Latch High */ +#define XR20M117X_DLD_REG (0x02) /* Divisor Fractional Register */ /* Enhanced Register set: Only if (LCR == 0xBF) */ #define SC16IS7XX_EFR_REG (0x02) /* Enhanced Features */ @@ -221,6 +223,20 @@ #define SC16IS7XX_TCR_RX_HALT(words) ((((words) / 4) & 0x0f) << 0) #define SC16IS7XX_TCR_RX_RESUME(words) ((((words) / 4) & 0x0f) << 4) +/* + * Divisor Fractional Register bits (EXAR extension). + * EXAR hardware is mostly compatible with SC16IS7XX, but supports additional feature: + * 4x and 8x divisor, instead of default 16x. It has a special register to program it. + * Bits 0 to 3 is fractional divisor, it used to set value of last 16 bits of + * uartclk * (16 / divisor) / baud, in case of default it will be uartclk / baud. + * Bits 4 and 5 used as switches, and should not be set to 1 simultaneously. + */ + +#define XR20M117X_DLD_16X 0 +#define XR20M117X_DLD_DIV_MASK GENMASK(3, 0) +#define XR20M117X_DLD_8X BIT(4) +#define XR20M117X_DLD_4X BIT(5) + /* * TLR register bits * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the @@ -523,6 +539,13 @@ const struct sc16is7xx_devtype sc16is762_devtype = { }; EXPORT_SYMBOL_GPL(sc16is762_devtype); +static const struct sc16is7xx_devtype xr20m1172_devtype = { + .name = "XR20M1172", + .nr_gpio = 8, + .nr_uart = 2, +}; +EXPORT_SYMBOL_GPL(sc16is762_devtype); + static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg) { switch (reg) { @@ -555,18 +578,43 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) return reg == SC16IS7XX_RHR_REG; } +static bool sc16is7xx_has_dld(struct device *dev) +{ + struct sc16is7xx_port *s = dev_get_drvdata(dev); + + if (s->devtype == &xr20m1172_devtype) + return true; + return false; +} + static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); - u8 lcr; + unsigned long clk = port->uartclk, div, div16; + bool has_dld = sc16is7xx_has_dld(port->dev); + u8 dld_mode = XR20M117X_DLD_16X; u8 prescaler = 0; - unsigned long clk = port->uartclk, div = clk / 16 / baud; + u8 divisor = 16; + u8 lcr; + + if (has_dld && DIV_ROUND_CLOSEST(clk, baud) < 16) + divisor = rounddown_pow_of_two(DIV_ROUND_CLOSEST(clk, baud)); + + div16 = (clk * 16) / divisor / baud; + div = div16 / 16; if (div >= BIT(16)) { prescaler = SC16IS7XX_MCR_CLKSEL_BIT; div /= 4; } + /* Count additional divisor for EXAR devices */ + if (divisor == 8) + dld_mode = XR20M117X_DLD_8X; + if (divisor == 4) + dld_mode = XR20M117X_DLD_4X; + dld_mode |= FIELD_PREP(XR20M117X_DLD_DIV_MASK, div16); + /* Enable enhanced features */ sc16is7xx_efr_lock(port); sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, @@ -587,12 +635,14 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) regcache_cache_bypass(one->regmap, true); sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256); sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256); + if (has_dld) + sc16is7xx_port_write(port, XR20M117X_DLD_REG, dld_mode); regcache_cache_bypass(one->regmap, false); /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); - return DIV_ROUND_CLOSEST(clk / 16, div); + return DIV_ROUND_CLOSEST(clk / divisor, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen, @@ -1002,6 +1052,8 @@ static void sc16is7xx_set_termios(struct uart_port *port, const struct ktermios *old) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); + bool has_dld = sc16is7xx_has_dld(port->dev); + u8 divisor = has_dld ? 4 : 16 unsigned int lcr, flow = 0; int baud; unsigned long flags; @@ -1084,7 +1136,7 @@ static void sc16is7xx_set_termios(struct uart_port *port, /* Get baud rate generator configuration */ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 16 / 4 / 0xffff, - port->uartclk / 16); + port->uartclk / divisor); /* Setup baudrate generator */ baud = sc16is7xx_set_baud(port, baud); @@ -1684,6 +1736,7 @@ void sc16is7xx_remove(struct device *dev) EXPORT_SYMBOL_GPL(sc16is7xx_remove); const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = { + { .compatible = "exar,xr20m1172", .data = &xr20m1172_devtype, }, { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, }, { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, }, { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, }, diff --git a/drivers/tty/serial/sc16is7xx_i2c.c b/drivers/tty/serial/sc16is7xx_i2c.c index 3ed47c306d85..839de902821b 100644 --- a/drivers/tty/serial/sc16is7xx_i2c.c +++ b/drivers/tty/serial/sc16is7xx_i2c.c @@ -46,6 +46,7 @@ static const struct i2c_device_id sc16is7xx_i2c_id_table[] = { { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, }, { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, }, { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, }, + { "xr20m1172", (kernel_ulong_t)&xr20m1172_devtype, }, { } }; MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table); diff --git a/drivers/tty/serial/sc16is7xx_spi.c b/drivers/tty/serial/sc16is7xx_spi.c index 73df36f8a7fd..2b278282dbd0 100644 --- a/drivers/tty/serial/sc16is7xx_spi.c +++ b/drivers/tty/serial/sc16is7xx_spi.c @@ -69,6 +69,7 @@ static const struct spi_device_id sc16is7xx_spi_id_table[] = { { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, }, { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, }, { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, }, + { "xr20m1172", (kernel_ulong_t)&xr20m1172_devtype, }, { } }; MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);