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linux/drivers/tty/serial/max310x.c
Jan Kundrát 2b4bac48c1 serial: max310x: Use batched reads when reasonably safe 
The hardware has a 128 byte RX FIFO buffer for each independent UART.
Previously, the code was always reading that byte-by-byte via
independent SPI transactions and the associated overhead. In practice,
this led to up to eight bytes over SPI for just one byte in the UART's
RX FIFO:

- reading the global IRQ register (two bytes, one for command, the other
for data)
- reading one UART's ISR (again two bytes)
- reading the byte count (two bytes yet again)
- finally, reading one byte of the FIFO via another two-byte transaction

We cannot always use a batched read. If the TTY is set to intercept
break conditions or report framing or parity errors, then it is required
to check the Line Status Register (LSR) for each byte which is read from
the RX FIFO. The documentation does not show a way of doing that in a
single SPI transaction; registers 0x00 and 0x04 are separate.

In my testing, this is no silver bullet. I was feeding 2MB of random
data over four daisy-chaned UARTs of MAX14830, and this is the
distribution that I was getting:

- R <= 1: 7437322
- R <= 2: 162093
- R <= 4: 4093
- R <= 8: 4196
- R <= 16: 645
- R <= 32: 165
- R <= 64: 58
- R <= 128: 0

For a reference, batching the write operations works much better:

- W <= 1: 2664
- W <= 2: 1305
- W <= 4: 627
- W <= 8: 371
- W <= 16: 121
- W <= 32: 68
- W <= 64: 33
- W <= 128: 63139

That's probably because this HW/SW combination (Clearfog Base, Armada
388) is probably "good enough" to react to the chip's IRQ "fast enough"
most of the time. Still, I was getting RX overruns every now and then.
In future, I plan to improve this by letting the RX FIFO be filled a
little more (the chip has support for that and also for a "stale
timeout" to prevent additional starvation).

Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19 09:59:02 +01:00

1468 lines
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// 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/module.h>
#include <linux/of.h>
#include <linux/of_device.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_REVID_EXTREG MAX310X_REG_05 /* 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_devtype {
char name[9];
int nr;
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 max310x_port {
struct max310x_devtype *devtype;
struct regmap *regmap;
struct mutex mutex;
struct clk *clk;
#ifdef CONFIG_GPIOLIB
struct gpio_chip gpio;
#endif
struct max310x_one p[0];
};
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_port *s = dev_get_drvdata(port->dev);
unsigned int val = 0;
regmap_read(s->regmap, port->iobase + reg, &val);
return val;
}
static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
{
struct max310x_port *s = dev_get_drvdata(port->dev);
regmap_write(s->regmap, port->iobase + reg, val);
}
static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
{
struct max310x_port *s = dev_get_drvdata(port->dev);
regmap_update_bits(s->regmap, port->iobase + 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 = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
MAX310X_EXTREG_ENBL);
if (ret)
return ret;
regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
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 = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
MAX310X_EXTREG_ENBL);
if (ret)
return ret;
regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
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,
.detect = max3107_detect,
.power = max310x_power,
};
static const struct max310x_devtype max3108_devtype = {
.name = "MAX3108",
.nr = 1,
.detect = max3108_detect,
.power = max310x_power,
};
static const struct max310x_devtype max3109_devtype = {
.name = "MAX3109",
.nr = 2,
.detect = max3109_detect,
.power = max310x_power,
};
static const struct max310x_devtype max14830_devtype = {
.name = "MAX14830",
.nr = 4,
.detect = max14830_detect,
.power = max14830_power,
};
static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
{
switch (reg & 0x1f) {
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 & 0x1f) {
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 & 0x1f) {
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 int max310x_set_baud(struct uart_port *port, int baud)
{
unsigned int mode = 0, clk = port->uartclk, div = clk / baud;
/* Check for minimal value for divider */
if (div < 16)
div = 16;
if (clk % baud && (div / 16) < 0x8000) {
/* Mode x2 */
mode = MAX310X_BRGCFG_2XMODE_BIT;
clk = port->uartclk * 2;
div = clk / baud;
if (clk % baud && (div / 16) < 0x8000) {
/* Mode x4 */
mode = MAX310X_BRGCFG_4XMODE_BIT;
clk = port->uartclk * 4;
div = clk / baud;
}
}
max310x_port_write(port, MAX310X_BRGDIVMSB_REG, (div / 16) >> 8);
max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div / 16);
max310x_port_write(port, MAX310X_BRGCFG_REG, (div % 16) | mode);
return DIV_ROUND_CLOSEST(clk, div);
}
static int max310x_update_best_err(unsigned long f, long *besterr)
{
/* Use baudrate 115200 for calculate error */
long err = f % (115200 * 16);
if ((*besterr < 0) || (*besterr > err)) {
*besterr = err;
return 0;
}
return 1;
}
static int max310x_set_ref_clk(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 = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_BIT;
/* 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 (pllcfg && xtal)
msleep(10);
return (int)bestfreq;
}
static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
{
u8 header[] = { (port->iobase + MAX310X_THR_REG) | MAX310X_WRITE_BIT };
struct spi_transfer xfer[] = {
{
.tx_buf = &header,
.len = sizeof(header),
}, {
.tx_buf = txbuf,
.len = len,
}
};
spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
}
static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
{
u8 header[] = { port->iobase + MAX310X_RHR_REG };
struct spi_transfer xfer[] = {
{
.tx_buf = &header,
.len = sizeof(header),
}, {
.rx_buf = rxbuf,
.len = len,
}
};
spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
}
static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
{
unsigned int sts, ch, flag, i;
u8 buf[MAX310X_FIFO_SIZE];
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, 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; ++i) {
uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, buf[i], 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);
}
/* Add data to send */
port->icount.tx += to_send;
xmit->tail = (xmit->tail + to_send) & (UART_XMIT_SIZE - 1);
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
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) {
mutex_lock(&s->mutex);
max310x_handle_tx(port);
mutex_unlock(&s->mutex);
}
} 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_wq_proc(struct work_struct *ws)
{
struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
struct max310x_port *s = dev_get_drvdata(one->port.dev);
mutex_lock(&s->mutex);
max310x_handle_tx(&one->port);
mutex_unlock(&s->mutex);
}
static void max310x_start_tx(struct uart_port *port)
{
struct max310x_one *one = container_of(port, struct max310x_one, port);
if (!work_pending(&one->tx_work))
schedule_work(&one->tx_work);
}
static unsigned int max310x_tx_empty(struct uart_port *port)
{
unsigned int lvl, sts;
lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
sts = max310x_port_read(port, MAX310X_IRQSTS_REG);
return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0;
}
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 = container_of(port, struct max310x_one, 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,
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]);
if (termios->c_cflag & CRTSCTS)
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)
flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
MAX310X_FLOWCTRL_SWFLOWEN_BIT;
max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
/* 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 val;
val = (one->port.rs485.delay_rts_before_send << 4) |
one->port.rs485.delay_rts_after_send;
max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, val);
if (one->port.rs485.flags & SER_RS485_ENABLED) {
max310x_port_update(&one->port, MAX310X_MODE1_REG,
MAX310X_MODE1_TRNSCVCTRL_BIT,
MAX310X_MODE1_TRNSCVCTRL_BIT);
max310x_port_update(&one->port, MAX310X_MODE2_REG,
MAX310X_MODE2_ECHOSUPR_BIT,
MAX310X_MODE2_ECHOSUPR_BIT);
} else {
max310x_port_update(&one->port, MAX310X_MODE1_REG,
MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
max310x_port_update(&one->port, MAX310X_MODE2_REG,
MAX310X_MODE2_ECHOSUPR_BIT, 0);
}
}
static int max310x_rs485_config(struct uart_port *port,
struct serial_rs485 *rs485)
{
struct max310x_one *one = container_of(port, struct max310x_one, port);
if ((rs485->delay_rts_before_send > 0x0f) ||
(rs485->delay_rts_after_send > 0x0f))
return -ERANGE;
rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_ENABLED;
memset(rs485->padding, 0, sizeof(rs485->padding));
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 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;
}
#endif
static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
struct regmap *regmap, int irq)
{
int i, ret, fmin, fmax, freq, uartclk;
struct clk *clk_osc, *clk_xtal;
struct max310x_port *s;
bool xtal = false;
if (IS_ERR(regmap))
return PTR_ERR(regmap);
/* Alloc port structure */
s = devm_kzalloc(dev, sizeof(*s) +
sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL);
if (!s) {
dev_err(dev, "Error allocating port structure\n");
return -ENOMEM;
}
clk_osc = devm_clk_get(dev, "osc");
clk_xtal = devm_clk_get(dev, "xtal");
if (!IS_ERR(clk_osc)) {
s->clk = clk_osc;
fmin = 500000;
fmax = 35000000;
} else if (!IS_ERR(clk_xtal)) {
s->clk = clk_xtal;
fmin = 1000000;
fmax = 4000000;
xtal = true;
} else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
return -EPROBE_DEFER;
} else {
dev_err(dev, "Cannot get clock\n");
return -EINVAL;
}
ret = clk_prepare_enable(s->clk);
if (ret)
return ret;
freq = clk_get_rate(s->clk);
/* Check frequency limits */
if (freq < fmin || freq > fmax) {
ret = -ERANGE;
goto out_clk;
}
s->regmap = regmap;
s->devtype = devtype;
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++) {
unsigned int offs = i << 5;
/* Reset port */
regmap_write(s->regmap, MAX310X_MODE2_REG + offs,
MAX310X_MODE2_RST_BIT);
/* Clear port reset */
regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0);
/* Wait for port startup */
do {
regmap_read(s->regmap,
MAX310X_BRGDIVLSB_REG + offs, &ret);
} while (ret != 0x01);
regmap_update_bits(s->regmap, MAX310X_MODE1_REG + offs,
MAX310X_MODE1_AUTOSLEEP_BIT,
MAX310X_MODE1_AUTOSLEEP_BIT);
}
uartclk = max310x_set_ref_clk(s, freq, xtal);
dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
mutex_init(&s->mutex);
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 * 0x20;
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.ops = &max310x_ops;
/* 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);
/* Enable IRQ pin */
max310x_port_update(&s->p[i].port, MAX310X_MODE1_REG,
MAX310X_MODE1_IRQSEL_BIT,
MAX310X_MODE1_IRQSEL_BIT);
/* Initialize queue for start TX */
INIT_WORK(&s->p[i].tx_work, max310x_wq_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 cotroller */
s->gpio.owner = THIS_MODULE;
s->gpio.parent = dev;
s->gpio.label = dev_name(dev);
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.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);
}
}
mutex_destroy(&s->mutex);
out_clk:
clk_disable_unprepare(s->clk);
return ret;
}
static int 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);
}
mutex_destroy(&s->mutex);
clk_disable_unprepare(s->clk);
return 0;
}
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,
.writeable_reg = max310x_reg_writeable,
.volatile_reg = max310x_reg_volatile,
.precious_reg = max310x_reg_precious,
};
#ifdef CONFIG_SPI_MASTER
static int max310x_spi_probe(struct spi_device *spi)
{
struct max310x_devtype *devtype;
struct regmap *regmap;
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;
if (spi->dev.of_node) {
const struct of_device_id *of_id =
of_match_device(max310x_dt_ids, &spi->dev);
devtype = (struct max310x_devtype *)of_id->data;
} else {
const struct spi_device_id *id_entry = spi_get_device_id(spi);
devtype = (struct max310x_devtype *)id_entry->driver_data;
}
regcfg.max_register = devtype->nr * 0x20 - 1;
regmap = devm_regmap_init_spi(spi, &regcfg);
return max310x_probe(&spi->dev, devtype, regmap, spi->irq);
}
static int max310x_spi_remove(struct spi_device *spi)
{
return 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 = of_match_ptr(max310x_dt_ids),
.pm = &max310x_pm_ops,
},
.probe = max310x_spi_probe,
.remove = max310x_spi_remove,
.id_table = max310x_id_table,
};
#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
spi_register_driver(&max310x_spi_driver);
#endif
return 0;
}
module_init(max310x_uart_init);
static void __exit max310x_uart_exit(void)
{
#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");
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