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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/tty/serial/max310x.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/tty/serial/max310x.c')
-rw-r--r--drivers/tty/serial/max310x.c1702
1 files changed, 1702 insertions, 0 deletions
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
new file mode 100644
index 000000000..db3204d2a
--- /dev/null
+++ b/drivers/tty/serial/max310x.c
@@ -0,0 +1,1702 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Maxim (Dallas) MAX3107/8/9, MAX14830 serial driver
+ *
+ * Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * Based on max3100.c, by Christian Pellegrin <chripell@evolware.org>
+ * Based on max3110.c, by Feng Tang <feng.tang@intel.com>
+ * Based on max3107.c, by Aavamobile
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/spi/spi.h>
+#include <linux/uaccess.h>
+
+#define MAX310X_NAME "max310x"
+#define MAX310X_MAJOR 204
+#define MAX310X_MINOR 209
+#define MAX310X_UART_NRMAX 16
+
+/* MAX310X register definitions */
+#define MAX310X_RHR_REG (0x00) /* RX FIFO */
+#define MAX310X_THR_REG (0x00) /* TX FIFO */
+#define MAX310X_IRQEN_REG (0x01) /* IRQ enable */
+#define MAX310X_IRQSTS_REG (0x02) /* IRQ status */
+#define MAX310X_LSR_IRQEN_REG (0x03) /* LSR IRQ enable */
+#define MAX310X_LSR_IRQSTS_REG (0x04) /* LSR IRQ status */
+#define MAX310X_REG_05 (0x05)
+#define MAX310X_SPCHR_IRQEN_REG MAX310X_REG_05 /* Special char IRQ en */
+#define MAX310X_SPCHR_IRQSTS_REG (0x06) /* Special char IRQ status */
+#define MAX310X_STS_IRQEN_REG (0x07) /* Status IRQ enable */
+#define MAX310X_STS_IRQSTS_REG (0x08) /* Status IRQ status */
+#define MAX310X_MODE1_REG (0x09) /* MODE1 */
+#define MAX310X_MODE2_REG (0x0a) /* MODE2 */
+#define MAX310X_LCR_REG (0x0b) /* LCR */
+#define MAX310X_RXTO_REG (0x0c) /* RX timeout */
+#define MAX310X_HDPIXDELAY_REG (0x0d) /* Auto transceiver delays */
+#define MAX310X_IRDA_REG (0x0e) /* IRDA settings */
+#define MAX310X_FLOWLVL_REG (0x0f) /* Flow control levels */
+#define MAX310X_FIFOTRIGLVL_REG (0x10) /* FIFO IRQ trigger levels */
+#define MAX310X_TXFIFOLVL_REG (0x11) /* TX FIFO level */
+#define MAX310X_RXFIFOLVL_REG (0x12) /* RX FIFO level */
+#define MAX310X_FLOWCTRL_REG (0x13) /* Flow control */
+#define MAX310X_XON1_REG (0x14) /* XON1 character */
+#define MAX310X_XON2_REG (0x15) /* XON2 character */
+#define MAX310X_XOFF1_REG (0x16) /* XOFF1 character */
+#define MAX310X_XOFF2_REG (0x17) /* XOFF2 character */
+#define MAX310X_GPIOCFG_REG (0x18) /* GPIO config */
+#define MAX310X_GPIODATA_REG (0x19) /* GPIO data */
+#define MAX310X_PLLCFG_REG (0x1a) /* PLL config */
+#define MAX310X_BRGCFG_REG (0x1b) /* Baud rate generator conf */
+#define MAX310X_BRGDIVLSB_REG (0x1c) /* Baud rate divisor LSB */
+#define MAX310X_BRGDIVMSB_REG (0x1d) /* Baud rate divisor MSB */
+#define MAX310X_CLKSRC_REG (0x1e) /* Clock source */
+#define MAX310X_REG_1F (0x1f)
+
+#define MAX310X_REVID_REG MAX310X_REG_1F /* Revision ID */
+
+#define MAX310X_GLOBALIRQ_REG MAX310X_REG_1F /* Global IRQ (RO) */
+#define MAX310X_GLOBALCMD_REG MAX310X_REG_1F /* Global Command (WO) */
+
+/* Extended registers */
+#define MAX310X_SPI_REVID_EXTREG MAX310X_REG_05 /* Revision ID */
+#define MAX310X_I2C_REVID_EXTREG (0x25) /* Revision ID */
+
+/* IRQ register bits */
+#define MAX310X_IRQ_LSR_BIT (1 << 0) /* LSR interrupt */
+#define MAX310X_IRQ_SPCHR_BIT (1 << 1) /* Special char interrupt */
+#define MAX310X_IRQ_STS_BIT (1 << 2) /* Status interrupt */
+#define MAX310X_IRQ_RXFIFO_BIT (1 << 3) /* RX FIFO interrupt */
+#define MAX310X_IRQ_TXFIFO_BIT (1 << 4) /* TX FIFO interrupt */
+#define MAX310X_IRQ_TXEMPTY_BIT (1 << 5) /* TX FIFO empty interrupt */
+#define MAX310X_IRQ_RXEMPTY_BIT (1 << 6) /* RX FIFO empty interrupt */
+#define MAX310X_IRQ_CTS_BIT (1 << 7) /* CTS interrupt */
+
+/* LSR register bits */
+#define MAX310X_LSR_RXTO_BIT (1 << 0) /* RX timeout */
+#define MAX310X_LSR_RXOVR_BIT (1 << 1) /* RX overrun */
+#define MAX310X_LSR_RXPAR_BIT (1 << 2) /* RX parity error */
+#define MAX310X_LSR_FRERR_BIT (1 << 3) /* Frame error */
+#define MAX310X_LSR_RXBRK_BIT (1 << 4) /* RX break */
+#define MAX310X_LSR_RXNOISE_BIT (1 << 5) /* RX noise */
+#define MAX310X_LSR_CTS_BIT (1 << 7) /* CTS pin state */
+
+/* Special character register bits */
+#define MAX310X_SPCHR_XON1_BIT (1 << 0) /* XON1 character */
+#define MAX310X_SPCHR_XON2_BIT (1 << 1) /* XON2 character */
+#define MAX310X_SPCHR_XOFF1_BIT (1 << 2) /* XOFF1 character */
+#define MAX310X_SPCHR_XOFF2_BIT (1 << 3) /* XOFF2 character */
+#define MAX310X_SPCHR_BREAK_BIT (1 << 4) /* RX break */
+#define MAX310X_SPCHR_MULTIDROP_BIT (1 << 5) /* 9-bit multidrop addr char */
+
+/* Status register bits */
+#define MAX310X_STS_GPIO0_BIT (1 << 0) /* GPIO 0 interrupt */
+#define MAX310X_STS_GPIO1_BIT (1 << 1) /* GPIO 1 interrupt */
+#define MAX310X_STS_GPIO2_BIT (1 << 2) /* GPIO 2 interrupt */
+#define MAX310X_STS_GPIO3_BIT (1 << 3) /* GPIO 3 interrupt */
+#define MAX310X_STS_CLKREADY_BIT (1 << 5) /* Clock ready */
+#define MAX310X_STS_SLEEP_BIT (1 << 6) /* Sleep interrupt */
+
+/* MODE1 register bits */
+#define MAX310X_MODE1_RXDIS_BIT (1 << 0) /* RX disable */
+#define MAX310X_MODE1_TXDIS_BIT (1 << 1) /* TX disable */
+#define MAX310X_MODE1_TXHIZ_BIT (1 << 2) /* TX pin three-state */
+#define MAX310X_MODE1_RTSHIZ_BIT (1 << 3) /* RTS pin three-state */
+#define MAX310X_MODE1_TRNSCVCTRL_BIT (1 << 4) /* Transceiver ctrl enable */
+#define MAX310X_MODE1_FORCESLEEP_BIT (1 << 5) /* Force sleep mode */
+#define MAX310X_MODE1_AUTOSLEEP_BIT (1 << 6) /* Auto sleep enable */
+#define MAX310X_MODE1_IRQSEL_BIT (1 << 7) /* IRQ pin enable */
+
+/* MODE2 register bits */
+#define MAX310X_MODE2_RST_BIT (1 << 0) /* Chip reset */
+#define MAX310X_MODE2_FIFORST_BIT (1 << 1) /* FIFO reset */
+#define MAX310X_MODE2_RXTRIGINV_BIT (1 << 2) /* RX FIFO INT invert */
+#define MAX310X_MODE2_RXEMPTINV_BIT (1 << 3) /* RX FIFO empty INT invert */
+#define MAX310X_MODE2_SPCHR_BIT (1 << 4) /* Special chr detect enable */
+#define MAX310X_MODE2_LOOPBACK_BIT (1 << 5) /* Internal loopback enable */
+#define MAX310X_MODE2_MULTIDROP_BIT (1 << 6) /* 9-bit multidrop enable */
+#define MAX310X_MODE2_ECHOSUPR_BIT (1 << 7) /* ECHO suppression enable */
+
+/* LCR register bits */
+#define MAX310X_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
+#define MAX310X_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
+ *
+ * Word length bits table:
+ * 00 -> 5 bit words
+ * 01 -> 6 bit words
+ * 10 -> 7 bit words
+ * 11 -> 8 bit words
+ */
+#define MAX310X_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
+ *
+ * STOP length bit table:
+ * 0 -> 1 stop bit
+ * 1 -> 1-1.5 stop bits if
+ * word length is 5,
+ * 2 stop bits otherwise
+ */
+#define MAX310X_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
+#define MAX310X_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
+#define MAX310X_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
+#define MAX310X_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
+#define MAX310X_LCR_RTS_BIT (1 << 7) /* RTS pin control */
+
+/* IRDA register bits */
+#define MAX310X_IRDA_IRDAEN_BIT (1 << 0) /* IRDA mode enable */
+#define MAX310X_IRDA_SIR_BIT (1 << 1) /* SIR mode enable */
+
+/* Flow control trigger level register masks */
+#define MAX310X_FLOWLVL_HALT_MASK (0x000f) /* Flow control halt level */
+#define MAX310X_FLOWLVL_RES_MASK (0x00f0) /* Flow control resume level */
+#define MAX310X_FLOWLVL_HALT(words) ((words / 8) & 0x0f)
+#define MAX310X_FLOWLVL_RES(words) (((words / 8) & 0x0f) << 4)
+
+/* FIFO interrupt trigger level register masks */
+#define MAX310X_FIFOTRIGLVL_TX_MASK (0x0f) /* TX FIFO trigger level */
+#define MAX310X_FIFOTRIGLVL_RX_MASK (0xf0) /* RX FIFO trigger level */
+#define MAX310X_FIFOTRIGLVL_TX(words) ((words / 8) & 0x0f)
+#define MAX310X_FIFOTRIGLVL_RX(words) (((words / 8) & 0x0f) << 4)
+
+/* Flow control register bits */
+#define MAX310X_FLOWCTRL_AUTORTS_BIT (1 << 0) /* Auto RTS flow ctrl enable */
+#define MAX310X_FLOWCTRL_AUTOCTS_BIT (1 << 1) /* Auto CTS flow ctrl enable */
+#define MAX310X_FLOWCTRL_GPIADDR_BIT (1 << 2) /* Enables that GPIO inputs
+ * are used in conjunction with
+ * XOFF2 for definition of
+ * special character */
+#define MAX310X_FLOWCTRL_SWFLOWEN_BIT (1 << 3) /* Auto SW flow ctrl enable */
+#define MAX310X_FLOWCTRL_SWFLOW0_BIT (1 << 4) /* SWFLOW bit 0 */
+#define MAX310X_FLOWCTRL_SWFLOW1_BIT (1 << 5) /* SWFLOW bit 1
+ *
+ * SWFLOW bits 1 & 0 table:
+ * 00 -> no transmitter flow
+ * control
+ * 01 -> receiver compares
+ * XON2 and XOFF2
+ * and controls
+ * transmitter
+ * 10 -> receiver compares
+ * XON1 and XOFF1
+ * and controls
+ * transmitter
+ * 11 -> receiver compares
+ * XON1, XON2, XOFF1 and
+ * XOFF2 and controls
+ * transmitter
+ */
+#define MAX310X_FLOWCTRL_SWFLOW2_BIT (1 << 6) /* SWFLOW bit 2 */
+#define MAX310X_FLOWCTRL_SWFLOW3_BIT (1 << 7) /* SWFLOW bit 3
+ *
+ * SWFLOW bits 3 & 2 table:
+ * 00 -> no received flow
+ * control
+ * 01 -> transmitter generates
+ * XON2 and XOFF2
+ * 10 -> transmitter generates
+ * XON1 and XOFF1
+ * 11 -> transmitter generates
+ * XON1, XON2, XOFF1 and
+ * XOFF2
+ */
+
+/* PLL configuration register masks */
+#define MAX310X_PLLCFG_PREDIV_MASK (0x3f) /* PLL predivision value */
+#define MAX310X_PLLCFG_PLLFACTOR_MASK (0xc0) /* PLL multiplication factor */
+
+/* Baud rate generator configuration register bits */
+#define MAX310X_BRGCFG_2XMODE_BIT (1 << 4) /* Double baud rate */
+#define MAX310X_BRGCFG_4XMODE_BIT (1 << 5) /* Quadruple baud rate */
+
+/* Clock source register bits */
+#define MAX310X_CLKSRC_CRYST_BIT (1 << 1) /* Crystal osc enable */
+#define MAX310X_CLKSRC_PLL_BIT (1 << 2) /* PLL enable */
+#define MAX310X_CLKSRC_PLLBYP_BIT (1 << 3) /* PLL bypass */
+#define MAX310X_CLKSRC_EXTCLK_BIT (1 << 4) /* External clock enable */
+#define MAX310X_CLKSRC_CLK2RTS_BIT (1 << 7) /* Baud clk to RTS pin */
+
+/* Global commands */
+#define MAX310X_EXTREG_ENBL (0xce)
+#define MAX310X_EXTREG_DSBL (0xcd)
+
+/* Misc definitions */
+#define MAX310X_FIFO_SIZE (128)
+#define MAX310x_REV_MASK (0xf8)
+#define MAX310X_WRITE_BIT 0x80
+
+/* MAX3107 specific */
+#define MAX3107_REV_ID (0xa0)
+
+/* MAX3109 specific */
+#define MAX3109_REV_ID (0xc0)
+
+/* MAX14830 specific */
+#define MAX14830_BRGCFG_CLKDIS_BIT (1 << 6) /* Clock Disable */
+#define MAX14830_REV_ID (0xb0)
+
+struct max310x_if_cfg {
+ int (*extended_reg_enable)(struct device *dev, bool enable);
+
+ unsigned int rev_id_reg;
+};
+
+struct max310x_devtype {
+ struct {
+ unsigned short min;
+ unsigned short max;
+ } slave_addr;
+ char name[9];
+ int nr;
+ u8 mode1;
+ int (*detect)(struct device *);
+ void (*power)(struct uart_port *, int);
+};
+
+struct max310x_one {
+ struct uart_port port;
+ struct work_struct tx_work;
+ struct work_struct md_work;
+ struct work_struct rs_work;
+ struct regmap *regmap;
+
+ u8 rx_buf[MAX310X_FIFO_SIZE];
+};
+#define to_max310x_port(_port) \
+ container_of(_port, struct max310x_one, port)
+
+struct max310x_port {
+ const struct max310x_devtype *devtype;
+ const struct max310x_if_cfg *if_cfg;
+ struct regmap *regmap;
+ struct clk *clk;
+#ifdef CONFIG_GPIOLIB
+ struct gpio_chip gpio;
+#endif
+ struct max310x_one p[];
+};
+
+static struct uart_driver max310x_uart = {
+ .owner = THIS_MODULE,
+ .driver_name = MAX310X_NAME,
+ .dev_name = "ttyMAX",
+ .major = MAX310X_MAJOR,
+ .minor = MAX310X_MINOR,
+ .nr = MAX310X_UART_NRMAX,
+};
+
+static DECLARE_BITMAP(max310x_lines, MAX310X_UART_NRMAX);
+
+static u8 max310x_port_read(struct uart_port *port, u8 reg)
+{
+ struct max310x_one *one = to_max310x_port(port);
+ unsigned int val = 0;
+
+ regmap_read(one->regmap, reg, &val);
+
+ return val;
+}
+
+static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
+{
+ struct max310x_one *one = to_max310x_port(port);
+
+ regmap_write(one->regmap, reg, val);
+}
+
+static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
+{
+ struct max310x_one *one = to_max310x_port(port);
+
+ regmap_update_bits(one->regmap, reg, mask, val);
+}
+
+static int max3107_detect(struct device *dev)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+ unsigned int val = 0;
+ int ret;
+
+ ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
+ if (ret)
+ return ret;
+
+ if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) {
+ dev_err(dev,
+ "%s ID 0x%02x does not match\n", s->devtype->name, val);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int max3108_detect(struct device *dev)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+ unsigned int val = 0;
+ int ret;
+
+ /* MAX3108 have not REV ID register, we just check default value
+ * from clocksource register to make sure everything works.
+ */
+ ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
+ if (ret)
+ return ret;
+
+ if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) {
+ dev_err(dev, "%s not present\n", s->devtype->name);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int max3109_detect(struct device *dev)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+ unsigned int val = 0;
+ int ret;
+
+ ret = s->if_cfg->extended_reg_enable(dev, true);
+ if (ret)
+ return ret;
+
+ regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
+ s->if_cfg->extended_reg_enable(dev, false);
+ if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
+ dev_err(dev,
+ "%s ID 0x%02x does not match\n", s->devtype->name, val);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static void max310x_power(struct uart_port *port, int on)
+{
+ max310x_port_update(port, MAX310X_MODE1_REG,
+ MAX310X_MODE1_FORCESLEEP_BIT,
+ on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
+ if (on)
+ msleep(50);
+}
+
+static int max14830_detect(struct device *dev)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+ unsigned int val = 0;
+ int ret;
+
+ ret = s->if_cfg->extended_reg_enable(dev, true);
+ if (ret)
+ return ret;
+
+ regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
+ s->if_cfg->extended_reg_enable(dev, false);
+ if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
+ dev_err(dev,
+ "%s ID 0x%02x does not match\n", s->devtype->name, val);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static void max14830_power(struct uart_port *port, int on)
+{
+ max310x_port_update(port, MAX310X_BRGCFG_REG,
+ MAX14830_BRGCFG_CLKDIS_BIT,
+ on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
+ if (on)
+ msleep(50);
+}
+
+static const struct max310x_devtype max3107_devtype = {
+ .name = "MAX3107",
+ .nr = 1,
+ .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT | MAX310X_MODE1_IRQSEL_BIT,
+ .detect = max3107_detect,
+ .power = max310x_power,
+ .slave_addr = {
+ .min = 0x2c,
+ .max = 0x2f,
+ },
+};
+
+static const struct max310x_devtype max3108_devtype = {
+ .name = "MAX3108",
+ .nr = 1,
+ .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
+ .detect = max3108_detect,
+ .power = max310x_power,
+ .slave_addr = {
+ .min = 0x60,
+ .max = 0x6f,
+ },
+};
+
+static const struct max310x_devtype max3109_devtype = {
+ .name = "MAX3109",
+ .nr = 2,
+ .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT,
+ .detect = max3109_detect,
+ .power = max310x_power,
+ .slave_addr = {
+ .min = 0x60,
+ .max = 0x6f,
+ },
+};
+
+static const struct max310x_devtype max14830_devtype = {
+ .name = "MAX14830",
+ .nr = 4,
+ .mode1 = MAX310X_MODE1_IRQSEL_BIT,
+ .detect = max14830_detect,
+ .power = max14830_power,
+ .slave_addr = {
+ .min = 0x60,
+ .max = 0x6f,
+ },
+};
+
+static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case MAX310X_IRQSTS_REG:
+ case MAX310X_LSR_IRQSTS_REG:
+ case MAX310X_SPCHR_IRQSTS_REG:
+ case MAX310X_STS_IRQSTS_REG:
+ case MAX310X_TXFIFOLVL_REG:
+ case MAX310X_RXFIFOLVL_REG:
+ return false;
+ default:
+ break;
+ }
+
+ return true;
+}
+
+static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case MAX310X_RHR_REG:
+ case MAX310X_IRQSTS_REG:
+ case MAX310X_LSR_IRQSTS_REG:
+ case MAX310X_SPCHR_IRQSTS_REG:
+ case MAX310X_STS_IRQSTS_REG:
+ case MAX310X_TXFIFOLVL_REG:
+ case MAX310X_RXFIFOLVL_REG:
+ case MAX310X_GPIODATA_REG:
+ case MAX310X_BRGDIVLSB_REG:
+ case MAX310X_REG_05:
+ case MAX310X_REG_1F:
+ return true;
+ default:
+ break;
+ }
+
+ return false;
+}
+
+static bool max310x_reg_precious(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case MAX310X_RHR_REG:
+ case MAX310X_IRQSTS_REG:
+ case MAX310X_SPCHR_IRQSTS_REG:
+ case MAX310X_STS_IRQSTS_REG:
+ return true;
+ default:
+ break;
+ }
+
+ return false;
+}
+
+static bool max310x_reg_noinc(struct device *dev, unsigned int reg)
+{
+ return reg == MAX310X_RHR_REG;
+}
+
+static int max310x_set_baud(struct uart_port *port, int baud)
+{
+ unsigned int mode = 0, div = 0, frac = 0, c = 0, F = 0;
+
+ /*
+ * Calculate the integer divisor first. Select a proper mode
+ * in case if the requested baud is too high for the pre-defined
+ * clocks frequency.
+ */
+ div = port->uartclk / baud;
+ if (div < 8) {
+ /* Mode x4 */
+ c = 4;
+ mode = MAX310X_BRGCFG_4XMODE_BIT;
+ } else if (div < 16) {
+ /* Mode x2 */
+ c = 8;
+ mode = MAX310X_BRGCFG_2XMODE_BIT;
+ } else {
+ c = 16;
+ }
+
+ /* Calculate the divisor in accordance with the fraction coefficient */
+ div /= c;
+ F = c*baud;
+
+ /* Calculate the baud rate fraction */
+ if (div > 0)
+ frac = (16*(port->uartclk % F)) / F;
+ else
+ div = 1;
+
+ max310x_port_write(port, MAX310X_BRGDIVMSB_REG, div >> 8);
+ max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div);
+ max310x_port_write(port, MAX310X_BRGCFG_REG, frac | mode);
+
+ /* Return the actual baud rate we just programmed */
+ return (16*port->uartclk) / (c*(16*div + frac));
+}
+
+static int max310x_update_best_err(unsigned long f, long *besterr)
+{
+ /* Use baudrate 115200 for calculate error */
+ long err = f % (460800 * 16);
+
+ if ((*besterr < 0) || (*besterr > err)) {
+ *besterr = err;
+ return 0;
+ }
+
+ return 1;
+}
+
+static u32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
+ unsigned long freq, bool xtal)
+{
+ unsigned int div, clksrc, pllcfg = 0;
+ long besterr = -1;
+ unsigned long fdiv, fmul, bestfreq = freq;
+
+ /* First, update error without PLL */
+ max310x_update_best_err(freq, &besterr);
+
+ /* Try all possible PLL dividers */
+ for (div = 1; (div <= 63) && besterr; div++) {
+ fdiv = DIV_ROUND_CLOSEST(freq, div);
+
+ /* Try multiplier 6 */
+ fmul = fdiv * 6;
+ if ((fdiv >= 500000) && (fdiv <= 800000))
+ if (!max310x_update_best_err(fmul, &besterr)) {
+ pllcfg = (0 << 6) | div;
+ bestfreq = fmul;
+ }
+ /* Try multiplier 48 */
+ fmul = fdiv * 48;
+ if ((fdiv >= 850000) && (fdiv <= 1200000))
+ if (!max310x_update_best_err(fmul, &besterr)) {
+ pllcfg = (1 << 6) | div;
+ bestfreq = fmul;
+ }
+ /* Try multiplier 96 */
+ fmul = fdiv * 96;
+ if ((fdiv >= 425000) && (fdiv <= 1000000))
+ if (!max310x_update_best_err(fmul, &besterr)) {
+ pllcfg = (2 << 6) | div;
+ bestfreq = fmul;
+ }
+ /* Try multiplier 144 */
+ fmul = fdiv * 144;
+ if ((fdiv >= 390000) && (fdiv <= 667000))
+ if (!max310x_update_best_err(fmul, &besterr)) {
+ pllcfg = (3 << 6) | div;
+ bestfreq = fmul;
+ }
+ }
+
+ /* Configure clock source */
+ clksrc = MAX310X_CLKSRC_EXTCLK_BIT | (xtal ? MAX310X_CLKSRC_CRYST_BIT : 0);
+
+ /* Configure PLL */
+ if (pllcfg) {
+ clksrc |= MAX310X_CLKSRC_PLL_BIT;
+ regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
+ } else
+ clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
+
+ regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
+
+ /* Wait for crystal */
+ if (xtal) {
+ unsigned int val;
+ msleep(10);
+ regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
+ if (!(val & MAX310X_STS_CLKREADY_BIT)) {
+ dev_warn(dev, "clock is not stable yet\n");
+ }
+ }
+
+ return bestfreq;
+}
+
+static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
+{
+ struct max310x_one *one = to_max310x_port(port);
+
+ regmap_noinc_write(one->regmap, MAX310X_THR_REG, txbuf, len);
+}
+
+static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
+{
+ struct max310x_one *one = to_max310x_port(port);
+
+ regmap_noinc_read(one->regmap, MAX310X_RHR_REG, rxbuf, len);
+}
+
+static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
+{
+ struct max310x_one *one = to_max310x_port(port);
+ unsigned int sts, i;
+ u8 ch, flag;
+
+ if (port->read_status_mask == MAX310X_LSR_RXOVR_BIT) {
+ /* We are just reading, happily ignoring any error conditions.
+ * Break condition, parity checking, framing errors -- they
+ * are all ignored. That means that we can do a batch-read.
+ *
+ * There is a small opportunity for race if the RX FIFO
+ * overruns while we're reading the buffer; the datasheets says
+ * that the LSR register applies to the "current" character.
+ * That's also the reason why we cannot do batched reads when
+ * asked to check the individual statuses.
+ * */
+
+ sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
+ max310x_batch_read(port, one->rx_buf, rxlen);
+
+ port->icount.rx += rxlen;
+ flag = TTY_NORMAL;
+ sts &= port->read_status_mask;
+
+ if (sts & MAX310X_LSR_RXOVR_BIT) {
+ dev_warn_ratelimited(port->dev, "Hardware RX FIFO overrun\n");
+ port->icount.overrun++;
+ }
+
+ for (i = 0; i < (rxlen - 1); ++i)
+ uart_insert_char(port, sts, 0, one->rx_buf[i], flag);
+
+ /*
+ * Handle the overrun case for the last character only, since
+ * the RxFIFO overflow happens after it is pushed to the FIFO
+ * tail.
+ */
+ uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT,
+ one->rx_buf[rxlen-1], flag);
+
+ } else {
+ if (unlikely(rxlen >= port->fifosize)) {
+ dev_warn_ratelimited(port->dev, "Possible RX FIFO overrun\n");
+ port->icount.buf_overrun++;
+ /* Ensure sanity of RX level */
+ rxlen = port->fifosize;
+ }
+
+ while (rxlen--) {
+ ch = max310x_port_read(port, MAX310X_RHR_REG);
+ sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
+
+ sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
+ MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
+
+ port->icount.rx++;
+ flag = TTY_NORMAL;
+
+ if (unlikely(sts)) {
+ if (sts & MAX310X_LSR_RXBRK_BIT) {
+ port->icount.brk++;
+ if (uart_handle_break(port))
+ continue;
+ } else if (sts & MAX310X_LSR_RXPAR_BIT)
+ port->icount.parity++;
+ else if (sts & MAX310X_LSR_FRERR_BIT)
+ port->icount.frame++;
+ else if (sts & MAX310X_LSR_RXOVR_BIT)
+ port->icount.overrun++;
+
+ sts &= port->read_status_mask;
+ if (sts & MAX310X_LSR_RXBRK_BIT)
+ flag = TTY_BREAK;
+ else if (sts & MAX310X_LSR_RXPAR_BIT)
+ flag = TTY_PARITY;
+ else if (sts & MAX310X_LSR_FRERR_BIT)
+ flag = TTY_FRAME;
+ else if (sts & MAX310X_LSR_RXOVR_BIT)
+ flag = TTY_OVERRUN;
+ }
+
+ if (uart_handle_sysrq_char(port, ch))
+ continue;
+
+ if (sts & port->ignore_status_mask)
+ continue;
+
+ uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
+ }
+ }
+
+ tty_flip_buffer_push(&port->state->port);
+}
+
+static void max310x_handle_tx(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+ unsigned int txlen, to_send, until_end;
+
+ if (unlikely(port->x_char)) {
+ max310x_port_write(port, MAX310X_THR_REG, port->x_char);
+ port->icount.tx++;
+ port->x_char = 0;
+ return;
+ }
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+ return;
+
+ /* Get length of data pending in circular buffer */
+ to_send = uart_circ_chars_pending(xmit);
+ until_end = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+ if (likely(to_send)) {
+ /* Limit to size of TX FIFO */
+ txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
+ txlen = port->fifosize - txlen;
+ to_send = (to_send > txlen) ? txlen : to_send;
+
+ if (until_end < to_send) {
+ /* It's a circ buffer -- wrap around.
+ * We could do that in one SPI transaction, but meh. */
+ max310x_batch_write(port, xmit->buf + xmit->tail, until_end);
+ max310x_batch_write(port, xmit->buf, to_send - until_end);
+ } else {
+ max310x_batch_write(port, xmit->buf + xmit->tail, to_send);
+ }
+ uart_xmit_advance(port, to_send);
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+}
+
+static void max310x_start_tx(struct uart_port *port)
+{
+ struct max310x_one *one = to_max310x_port(port);
+
+ schedule_work(&one->tx_work);
+}
+
+static irqreturn_t max310x_port_irq(struct max310x_port *s, int portno)
+{
+ struct uart_port *port = &s->p[portno].port;
+ irqreturn_t res = IRQ_NONE;
+
+ do {
+ unsigned int ists, lsr, rxlen;
+
+ /* Read IRQ status & RX FIFO level */
+ ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
+ rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
+ if (!ists && !rxlen)
+ break;
+
+ res = IRQ_HANDLED;
+
+ if (ists & MAX310X_IRQ_CTS_BIT) {
+ lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
+ uart_handle_cts_change(port, lsr & MAX310X_LSR_CTS_BIT);
+ }
+ if (rxlen)
+ max310x_handle_rx(port, rxlen);
+ if (ists & MAX310X_IRQ_TXEMPTY_BIT)
+ max310x_start_tx(port);
+ } while (1);
+ return res;
+}
+
+static irqreturn_t max310x_ist(int irq, void *dev_id)
+{
+ struct max310x_port *s = (struct max310x_port *)dev_id;
+ bool handled = false;
+
+ if (s->devtype->nr > 1) {
+ do {
+ unsigned int val = ~0;
+
+ WARN_ON_ONCE(regmap_read(s->regmap,
+ MAX310X_GLOBALIRQ_REG, &val));
+ val = ((1 << s->devtype->nr) - 1) & ~val;
+ if (!val)
+ break;
+ if (max310x_port_irq(s, fls(val) - 1) == IRQ_HANDLED)
+ handled = true;
+ } while (1);
+ } else {
+ if (max310x_port_irq(s, 0) == IRQ_HANDLED)
+ handled = true;
+ }
+
+ return IRQ_RETVAL(handled);
+}
+
+static void max310x_tx_proc(struct work_struct *ws)
+{
+ struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
+
+ max310x_handle_tx(&one->port);
+}
+
+static unsigned int max310x_tx_empty(struct uart_port *port)
+{
+ u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
+
+ return lvl ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int max310x_get_mctrl(struct uart_port *port)
+{
+ /* DCD and DSR are not wired and CTS/RTS is handled automatically
+ * so just indicate DSR and CAR asserted
+ */
+ return TIOCM_DSR | TIOCM_CAR;
+}
+
+static void max310x_md_proc(struct work_struct *ws)
+{
+ struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
+
+ max310x_port_update(&one->port, MAX310X_MODE2_REG,
+ MAX310X_MODE2_LOOPBACK_BIT,
+ (one->port.mctrl & TIOCM_LOOP) ?
+ MAX310X_MODE2_LOOPBACK_BIT : 0);
+}
+
+static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ struct max310x_one *one = to_max310x_port(port);
+
+ schedule_work(&one->md_work);
+}
+
+static void max310x_break_ctl(struct uart_port *port, int break_state)
+{
+ max310x_port_update(port, MAX310X_LCR_REG,
+ MAX310X_LCR_TXBREAK_BIT,
+ break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
+}
+
+static void max310x_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ const struct ktermios *old)
+{
+ unsigned int lcr = 0, flow = 0;
+ int baud;
+
+ /* Mask termios capabilities we don't support */
+ termios->c_cflag &= ~CMSPAR;
+
+ /* Word size */
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ break;
+ case CS6:
+ lcr = MAX310X_LCR_LENGTH0_BIT;
+ break;
+ case CS7:
+ lcr = MAX310X_LCR_LENGTH1_BIT;
+ break;
+ case CS8:
+ default:
+ lcr = MAX310X_LCR_LENGTH1_BIT | MAX310X_LCR_LENGTH0_BIT;
+ break;
+ }
+
+ /* Parity */
+ if (termios->c_cflag & PARENB) {
+ lcr |= MAX310X_LCR_PARITY_BIT;
+ if (!(termios->c_cflag & PARODD))
+ lcr |= MAX310X_LCR_EVENPARITY_BIT;
+ }
+
+ /* Stop bits */
+ if (termios->c_cflag & CSTOPB)
+ lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
+
+ /* Update LCR register */
+ max310x_port_write(port, MAX310X_LCR_REG, lcr);
+
+ /* Set read status mask */
+ port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
+ MAX310X_LSR_FRERR_BIT;
+ if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+ port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
+
+ /* Set status ignore mask */
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNBRK)
+ port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
+ if (!(termios->c_cflag & CREAD))
+ port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
+ MAX310X_LSR_RXOVR_BIT |
+ MAX310X_LSR_FRERR_BIT |
+ MAX310X_LSR_RXBRK_BIT;
+
+ /* Configure flow control */
+ max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
+ max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
+
+ /* Disable transmitter before enabling AutoCTS or auto transmitter
+ * flow control
+ */
+ if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) {
+ max310x_port_update(port, MAX310X_MODE1_REG,
+ MAX310X_MODE1_TXDIS_BIT,
+ MAX310X_MODE1_TXDIS_BIT);
+ }
+
+ port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
+
+ if (termios->c_cflag & CRTSCTS) {
+ /* Enable AUTORTS and AUTOCTS */
+ port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+ flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
+ MAX310X_FLOWCTRL_AUTORTS_BIT;
+ }
+ if (termios->c_iflag & IXON)
+ flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
+ MAX310X_FLOWCTRL_SWFLOWEN_BIT;
+ if (termios->c_iflag & IXOFF) {
+ port->status |= UPSTAT_AUTOXOFF;
+ flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
+ MAX310X_FLOWCTRL_SWFLOWEN_BIT;
+ }
+ max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
+
+ /* Enable transmitter after disabling AutoCTS and auto transmitter
+ * flow control
+ */
+ if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) {
+ max310x_port_update(port, MAX310X_MODE1_REG,
+ MAX310X_MODE1_TXDIS_BIT,
+ 0);
+ }
+
+ /* Get baud rate generator configuration */
+ baud = uart_get_baud_rate(port, termios, old,
+ port->uartclk / 16 / 0xffff,
+ port->uartclk / 4);
+
+ /* Setup baudrate generator */
+ baud = max310x_set_baud(port, baud);
+
+ /* Update timeout according to new baud rate */
+ uart_update_timeout(port, termios->c_cflag, baud);
+}
+
+static void max310x_rs_proc(struct work_struct *ws)
+{
+ struct max310x_one *one = container_of(ws, struct max310x_one, rs_work);
+ unsigned int delay, mode1 = 0, mode2 = 0;
+
+ delay = (one->port.rs485.delay_rts_before_send << 4) |
+ one->port.rs485.delay_rts_after_send;
+ max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, delay);
+
+ if (one->port.rs485.flags & SER_RS485_ENABLED) {
+ mode1 = MAX310X_MODE1_TRNSCVCTRL_BIT;
+
+ if (!(one->port.rs485.flags & SER_RS485_RX_DURING_TX))
+ mode2 = MAX310X_MODE2_ECHOSUPR_BIT;
+ }
+
+ max310x_port_update(&one->port, MAX310X_MODE1_REG,
+ MAX310X_MODE1_TRNSCVCTRL_BIT, mode1);
+ max310x_port_update(&one->port, MAX310X_MODE2_REG,
+ MAX310X_MODE2_ECHOSUPR_BIT, mode2);
+}
+
+static int max310x_rs485_config(struct uart_port *port, struct ktermios *termios,
+ struct serial_rs485 *rs485)
+{
+ struct max310x_one *one = to_max310x_port(port);
+
+ if ((rs485->delay_rts_before_send > 0x0f) ||
+ (rs485->delay_rts_after_send > 0x0f))
+ return -ERANGE;
+
+ port->rs485 = *rs485;
+
+ schedule_work(&one->rs_work);
+
+ return 0;
+}
+
+static int max310x_startup(struct uart_port *port)
+{
+ struct max310x_port *s = dev_get_drvdata(port->dev);
+ unsigned int val;
+
+ s->devtype->power(port, 1);
+
+ /* Configure MODE1 register */
+ max310x_port_update(port, MAX310X_MODE1_REG,
+ MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
+
+ /* Configure MODE2 register & Reset FIFOs*/
+ val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
+ max310x_port_write(port, MAX310X_MODE2_REG, val);
+ max310x_port_update(port, MAX310X_MODE2_REG,
+ MAX310X_MODE2_FIFORST_BIT, 0);
+
+ /* Configure mode1/mode2 to have rs485/rs232 enabled at startup */
+ val = (clamp(port->rs485.delay_rts_before_send, 0U, 15U) << 4) |
+ clamp(port->rs485.delay_rts_after_send, 0U, 15U);
+ max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
+
+ if (port->rs485.flags & SER_RS485_ENABLED) {
+ max310x_port_update(port, MAX310X_MODE1_REG,
+ MAX310X_MODE1_TRNSCVCTRL_BIT,
+ MAX310X_MODE1_TRNSCVCTRL_BIT);
+
+ if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+ max310x_port_update(port, MAX310X_MODE2_REG,
+ MAX310X_MODE2_ECHOSUPR_BIT,
+ MAX310X_MODE2_ECHOSUPR_BIT);
+ }
+
+ /* Configure flow control levels */
+ /* Flow control halt level 96, resume level 48 */
+ max310x_port_write(port, MAX310X_FLOWLVL_REG,
+ MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
+
+ /* Clear IRQ status register */
+ max310x_port_read(port, MAX310X_IRQSTS_REG);
+
+ /* Enable RX, TX, CTS change interrupts */
+ val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
+ max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
+
+ return 0;
+}
+
+static void max310x_shutdown(struct uart_port *port)
+{
+ struct max310x_port *s = dev_get_drvdata(port->dev);
+
+ /* Disable all interrupts */
+ max310x_port_write(port, MAX310X_IRQEN_REG, 0);
+
+ s->devtype->power(port, 0);
+}
+
+static const char *max310x_type(struct uart_port *port)
+{
+ struct max310x_port *s = dev_get_drvdata(port->dev);
+
+ return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
+}
+
+static int max310x_request_port(struct uart_port *port)
+{
+ /* Do nothing */
+ return 0;
+}
+
+static void max310x_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE)
+ port->type = PORT_MAX310X;
+}
+
+static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
+{
+ if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
+ return -EINVAL;
+ if (s->irq != port->irq)
+ return -EINVAL;
+
+ return 0;
+}
+
+static void max310x_null_void(struct uart_port *port)
+{
+ /* Do nothing */
+}
+
+static const struct uart_ops max310x_ops = {
+ .tx_empty = max310x_tx_empty,
+ .set_mctrl = max310x_set_mctrl,
+ .get_mctrl = max310x_get_mctrl,
+ .stop_tx = max310x_null_void,
+ .start_tx = max310x_start_tx,
+ .stop_rx = max310x_null_void,
+ .break_ctl = max310x_break_ctl,
+ .startup = max310x_startup,
+ .shutdown = max310x_shutdown,
+ .set_termios = max310x_set_termios,
+ .type = max310x_type,
+ .request_port = max310x_request_port,
+ .release_port = max310x_null_void,
+ .config_port = max310x_config_port,
+ .verify_port = max310x_verify_port,
+};
+
+static int __maybe_unused max310x_suspend(struct device *dev)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < s->devtype->nr; i++) {
+ uart_suspend_port(&max310x_uart, &s->p[i].port);
+ s->devtype->power(&s->p[i].port, 0);
+ }
+
+ return 0;
+}
+
+static int __maybe_unused max310x_resume(struct device *dev)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < s->devtype->nr; i++) {
+ s->devtype->power(&s->p[i].port, 1);
+ uart_resume_port(&max310x_uart, &s->p[i].port);
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
+
+#ifdef CONFIG_GPIOLIB
+static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ unsigned int val;
+ struct max310x_port *s = gpiochip_get_data(chip);
+ struct uart_port *port = &s->p[offset / 4].port;
+
+ val = max310x_port_read(port, MAX310X_GPIODATA_REG);
+
+ return !!((val >> 4) & (1 << (offset % 4)));
+}
+
+static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct max310x_port *s = gpiochip_get_data(chip);
+ struct uart_port *port = &s->p[offset / 4].port;
+
+ max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
+ value ? 1 << (offset % 4) : 0);
+}
+
+static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct max310x_port *s = gpiochip_get_data(chip);
+ struct uart_port *port = &s->p[offset / 4].port;
+
+ max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
+
+ return 0;
+}
+
+static int max310x_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct max310x_port *s = gpiochip_get_data(chip);
+ struct uart_port *port = &s->p[offset / 4].port;
+
+ max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
+ value ? 1 << (offset % 4) : 0);
+ max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
+ 1 << (offset % 4));
+
+ return 0;
+}
+
+static int max310x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
+ unsigned long config)
+{
+ struct max310x_port *s = gpiochip_get_data(chip);
+ struct uart_port *port = &s->p[offset / 4].port;
+
+ switch (pinconf_to_config_param(config)) {
+ case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+ max310x_port_update(port, MAX310X_GPIOCFG_REG,
+ 1 << ((offset % 4) + 4),
+ 1 << ((offset % 4) + 4));
+ return 0;
+ case PIN_CONFIG_DRIVE_PUSH_PULL:
+ max310x_port_update(port, MAX310X_GPIOCFG_REG,
+ 1 << ((offset % 4) + 4), 0);
+ return 0;
+ default:
+ return -ENOTSUPP;
+ }
+}
+#endif
+
+static const struct serial_rs485 max310x_rs485_supported = {
+ .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX,
+ .delay_rts_before_send = 1,
+ .delay_rts_after_send = 1,
+};
+
+static int max310x_probe(struct device *dev, const struct max310x_devtype *devtype,
+ const struct max310x_if_cfg *if_cfg,
+ struct regmap *regmaps[], int irq)
+{
+ int i, ret, fmin, fmax, freq;
+ struct max310x_port *s;
+ u32 uartclk = 0;
+ bool xtal;
+
+ for (i = 0; i < devtype->nr; i++)
+ if (IS_ERR(regmaps[i]))
+ return PTR_ERR(regmaps[i]);
+
+ /* Alloc port structure */
+ s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
+ if (!s) {
+ dev_err(dev, "Error allocating port structure\n");
+ return -ENOMEM;
+ }
+
+ /* Always ask for fixed clock rate from a property. */
+ device_property_read_u32(dev, "clock-frequency", &uartclk);
+
+ xtal = device_property_match_string(dev, "clock-names", "osc") < 0;
+ if (xtal)
+ s->clk = devm_clk_get_optional(dev, "xtal");
+ else
+ s->clk = devm_clk_get_optional(dev, "osc");
+ if (IS_ERR(s->clk))
+ return PTR_ERR(s->clk);
+
+ ret = clk_prepare_enable(s->clk);
+ if (ret)
+ return ret;
+
+ freq = clk_get_rate(s->clk);
+ if (freq == 0)
+ freq = uartclk;
+ if (freq == 0) {
+ dev_err(dev, "Cannot get clock rate\n");
+ ret = -EINVAL;
+ goto out_clk;
+ }
+
+ if (xtal) {
+ fmin = 1000000;
+ fmax = 4000000;
+ } else {
+ fmin = 500000;
+ fmax = 35000000;
+ }
+
+ /* Check frequency limits */
+ if (freq < fmin || freq > fmax) {
+ ret = -ERANGE;
+ goto out_clk;
+ }
+
+ s->regmap = regmaps[0];
+ s->devtype = devtype;
+ s->if_cfg = if_cfg;
+ dev_set_drvdata(dev, s);
+
+ /* Check device to ensure we are talking to what we expect */
+ ret = devtype->detect(dev);
+ if (ret)
+ goto out_clk;
+
+ for (i = 0; i < devtype->nr; i++) {
+ /* Reset port */
+ regmap_write(regmaps[i], MAX310X_MODE2_REG,
+ MAX310X_MODE2_RST_BIT);
+ /* Clear port reset */
+ regmap_write(regmaps[i], MAX310X_MODE2_REG, 0);
+
+ /* Wait for port startup */
+ do {
+ regmap_read(regmaps[i], MAX310X_BRGDIVLSB_REG, &ret);
+ } while (ret != 0x01);
+
+ regmap_write(regmaps[i], MAX310X_MODE1_REG, devtype->mode1);
+ }
+
+ uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
+ dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
+
+ for (i = 0; i < devtype->nr; i++) {
+ unsigned int line;
+
+ line = find_first_zero_bit(max310x_lines, MAX310X_UART_NRMAX);
+ if (line == MAX310X_UART_NRMAX) {
+ ret = -ERANGE;
+ goto out_uart;
+ }
+
+ /* Initialize port data */
+ s->p[i].port.line = line;
+ s->p[i].port.dev = dev;
+ s->p[i].port.irq = irq;
+ s->p[i].port.type = PORT_MAX310X;
+ s->p[i].port.fifosize = MAX310X_FIFO_SIZE;
+ s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
+ s->p[i].port.iotype = UPIO_PORT;
+ s->p[i].port.iobase = i;
+ /*
+ * Use all ones as membase to make sure uart_configure_port() in
+ * serial_core.c does not abort for SPI/I2C devices where the
+ * membase address is not applicable.
+ */
+ s->p[i].port.membase = (void __iomem *)~0;
+ s->p[i].port.uartclk = uartclk;
+ s->p[i].port.rs485_config = max310x_rs485_config;
+ s->p[i].port.rs485_supported = max310x_rs485_supported;
+ s->p[i].port.ops = &max310x_ops;
+ s->p[i].regmap = regmaps[i];
+
+ /* Disable all interrupts */
+ max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
+ /* Clear IRQ status register */
+ max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
+ /* Initialize queue for start TX */
+ INIT_WORK(&s->p[i].tx_work, max310x_tx_proc);
+ /* Initialize queue for changing LOOPBACK mode */
+ INIT_WORK(&s->p[i].md_work, max310x_md_proc);
+ /* Initialize queue for changing RS485 mode */
+ INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
+
+ /* Register port */
+ ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
+ if (ret) {
+ s->p[i].port.dev = NULL;
+ goto out_uart;
+ }
+ set_bit(line, max310x_lines);
+
+ /* Go to suspend mode */
+ devtype->power(&s->p[i].port, 0);
+ }
+
+#ifdef CONFIG_GPIOLIB
+ /* Setup GPIO controller */
+ s->gpio.owner = THIS_MODULE;
+ s->gpio.parent = dev;
+ s->gpio.label = devtype->name;
+ s->gpio.direction_input = max310x_gpio_direction_input;
+ s->gpio.get = max310x_gpio_get;
+ s->gpio.direction_output= max310x_gpio_direction_output;
+ s->gpio.set = max310x_gpio_set;
+ s->gpio.set_config = max310x_gpio_set_config;
+ s->gpio.base = -1;
+ s->gpio.ngpio = devtype->nr * 4;
+ s->gpio.can_sleep = 1;
+ ret = devm_gpiochip_add_data(dev, &s->gpio, s);
+ if (ret)
+ goto out_uart;
+#endif
+
+ /* Setup interrupt */
+ ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
+ IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), s);
+ if (!ret)
+ return 0;
+
+ dev_err(dev, "Unable to reguest IRQ %i\n", irq);
+
+out_uart:
+ for (i = 0; i < devtype->nr; i++) {
+ if (s->p[i].port.dev) {
+ uart_remove_one_port(&max310x_uart, &s->p[i].port);
+ clear_bit(s->p[i].port.line, max310x_lines);
+ }
+ }
+
+out_clk:
+ clk_disable_unprepare(s->clk);
+
+ return ret;
+}
+
+static void max310x_remove(struct device *dev)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < s->devtype->nr; i++) {
+ cancel_work_sync(&s->p[i].tx_work);
+ cancel_work_sync(&s->p[i].md_work);
+ cancel_work_sync(&s->p[i].rs_work);
+ uart_remove_one_port(&max310x_uart, &s->p[i].port);
+ clear_bit(s->p[i].port.line, max310x_lines);
+ s->devtype->power(&s->p[i].port, 0);
+ }
+
+ clk_disable_unprepare(s->clk);
+}
+
+static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
+ { .compatible = "maxim,max3107", .data = &max3107_devtype, },
+ { .compatible = "maxim,max3108", .data = &max3108_devtype, },
+ { .compatible = "maxim,max3109", .data = &max3109_devtype, },
+ { .compatible = "maxim,max14830", .data = &max14830_devtype },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max310x_dt_ids);
+
+static struct regmap_config regcfg = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .write_flag_mask = MAX310X_WRITE_BIT,
+ .cache_type = REGCACHE_RBTREE,
+ .max_register = MAX310X_REG_1F,
+ .writeable_reg = max310x_reg_writeable,
+ .volatile_reg = max310x_reg_volatile,
+ .precious_reg = max310x_reg_precious,
+ .writeable_noinc_reg = max310x_reg_noinc,
+ .readable_noinc_reg = max310x_reg_noinc,
+ .max_raw_read = MAX310X_FIFO_SIZE,
+ .max_raw_write = MAX310X_FIFO_SIZE,
+};
+
+#ifdef CONFIG_SPI_MASTER
+static int max310x_spi_extended_reg_enable(struct device *dev, bool enable)
+{
+ struct max310x_port *s = dev_get_drvdata(dev);
+
+ return regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
+ enable ? MAX310X_EXTREG_ENBL : MAX310X_EXTREG_DSBL);
+}
+
+static const struct max310x_if_cfg __maybe_unused max310x_spi_if_cfg = {
+ .extended_reg_enable = max310x_spi_extended_reg_enable,
+ .rev_id_reg = MAX310X_SPI_REVID_EXTREG,
+};
+
+static int max310x_spi_probe(struct spi_device *spi)
+{
+ const struct max310x_devtype *devtype;
+ struct regmap *regmaps[4];
+ unsigned int i;
+ int ret;
+
+ /* Setup SPI bus */
+ spi->bits_per_word = 8;
+ spi->mode = spi->mode ? : SPI_MODE_0;
+ spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
+ ret = spi_setup(spi);
+ if (ret)
+ return ret;
+
+ devtype = device_get_match_data(&spi->dev);
+ if (!devtype)
+ devtype = (struct max310x_devtype *)spi_get_device_id(spi)->driver_data;
+
+ for (i = 0; i < devtype->nr; i++) {
+ u8 port_mask = i * 0x20;
+ regcfg.read_flag_mask = port_mask;
+ regcfg.write_flag_mask = port_mask | MAX310X_WRITE_BIT;
+ regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
+ }
+
+ return max310x_probe(&spi->dev, devtype, &max310x_spi_if_cfg, regmaps, spi->irq);
+}
+
+static void max310x_spi_remove(struct spi_device *spi)
+{
+ max310x_remove(&spi->dev);
+}
+
+static const struct spi_device_id max310x_id_table[] = {
+ { "max3107", (kernel_ulong_t)&max3107_devtype, },
+ { "max3108", (kernel_ulong_t)&max3108_devtype, },
+ { "max3109", (kernel_ulong_t)&max3109_devtype, },
+ { "max14830", (kernel_ulong_t)&max14830_devtype, },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, max310x_id_table);
+
+static struct spi_driver max310x_spi_driver = {
+ .driver = {
+ .name = MAX310X_NAME,
+ .of_match_table = max310x_dt_ids,
+ .pm = &max310x_pm_ops,
+ },
+ .probe = max310x_spi_probe,
+ .remove = max310x_spi_remove,
+ .id_table = max310x_id_table,
+};
+#endif
+
+#ifdef CONFIG_I2C
+static int max310x_i2c_extended_reg_enable(struct device *dev, bool enable)
+{
+ return 0;
+}
+
+static struct regmap_config regcfg_i2c = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .cache_type = REGCACHE_RBTREE,
+ .writeable_reg = max310x_reg_writeable,
+ .volatile_reg = max310x_reg_volatile,
+ .precious_reg = max310x_reg_precious,
+ .max_register = MAX310X_I2C_REVID_EXTREG,
+ .writeable_noinc_reg = max310x_reg_noinc,
+ .readable_noinc_reg = max310x_reg_noinc,
+ .max_raw_read = MAX310X_FIFO_SIZE,
+ .max_raw_write = MAX310X_FIFO_SIZE,
+};
+
+static const struct max310x_if_cfg max310x_i2c_if_cfg = {
+ .extended_reg_enable = max310x_i2c_extended_reg_enable,
+ .rev_id_reg = MAX310X_I2C_REVID_EXTREG,
+};
+
+static unsigned short max310x_i2c_slave_addr(unsigned short addr,
+ unsigned int nr)
+{
+ /*
+ * For MAX14830 and MAX3109, the slave address depends on what the
+ * A0 and A1 pins are tied to.
+ * See Table I2C Address Map of the datasheet.
+ * Based on that table, the following formulas were determined.
+ * UART1 - UART0 = 0x10
+ * UART2 - UART1 = 0x20 + 0x10
+ * UART3 - UART2 = 0x10
+ */
+
+ addr -= nr * 0x10;
+
+ if (nr >= 2)
+ addr -= 0x20;
+
+ return addr;
+}
+
+static int max310x_i2c_probe(struct i2c_client *client)
+{
+ const struct max310x_devtype *devtype =
+ device_get_match_data(&client->dev);
+ struct i2c_client *port_client;
+ struct regmap *regmaps[4];
+ unsigned int i;
+ u8 port_addr;
+
+ if (client->addr < devtype->slave_addr.min ||
+ client->addr > devtype->slave_addr.max)
+ return dev_err_probe(&client->dev, -EINVAL,
+ "Slave addr 0x%x outside of range [0x%x, 0x%x]\n",
+ client->addr, devtype->slave_addr.min,
+ devtype->slave_addr.max);
+
+ regmaps[0] = devm_regmap_init_i2c(client, &regcfg_i2c);
+
+ for (i = 1; i < devtype->nr; i++) {
+ port_addr = max310x_i2c_slave_addr(client->addr, i);
+ port_client = devm_i2c_new_dummy_device(&client->dev,
+ client->adapter,
+ port_addr);
+
+ regmaps[i] = devm_regmap_init_i2c(port_client, &regcfg_i2c);
+ }
+
+ return max310x_probe(&client->dev, devtype, &max310x_i2c_if_cfg,
+ regmaps, client->irq);
+}
+
+static void max310x_i2c_remove(struct i2c_client *client)
+{
+ max310x_remove(&client->dev);
+}
+
+static struct i2c_driver max310x_i2c_driver = {
+ .driver = {
+ .name = MAX310X_NAME,
+ .of_match_table = max310x_dt_ids,
+ .pm = &max310x_pm_ops,
+ },
+ .probe = max310x_i2c_probe,
+ .remove = max310x_i2c_remove,
+};
+#endif
+
+static int __init max310x_uart_init(void)
+{
+ int ret;
+
+ bitmap_zero(max310x_lines, MAX310X_UART_NRMAX);
+
+ ret = uart_register_driver(&max310x_uart);
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_SPI_MASTER
+ ret = spi_register_driver(&max310x_spi_driver);
+ if (ret)
+ goto err_spi_register;
+#endif
+
+#ifdef CONFIG_I2C
+ ret = i2c_add_driver(&max310x_i2c_driver);
+ if (ret)
+ goto err_i2c_register;
+#endif
+
+ return 0;
+
+#ifdef CONFIG_I2C
+err_i2c_register:
+ spi_unregister_driver(&max310x_spi_driver);
+#endif
+
+err_spi_register:
+ uart_unregister_driver(&max310x_uart);
+
+ return ret;
+}
+module_init(max310x_uart_init);
+
+static void __exit max310x_uart_exit(void)
+{
+#ifdef CONFIG_I2C
+ i2c_del_driver(&max310x_i2c_driver);
+#endif
+
+#ifdef CONFIG_SPI_MASTER
+ spi_unregister_driver(&max310x_spi_driver);
+#endif
+
+ uart_unregister_driver(&max310x_uart);
+}
+module_exit(max310x_uart_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("MAX310X serial driver");