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qcom_geni_serial.c
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qcom_geni_serial.c
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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
/* Disable MMIO tracing to prevent excessive logging of unwanted MMIO traces */
#define __DISABLE_TRACE_MMIO__
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/pm_wakeirq.h>
#include <linux/qcom-geni-se.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <dt-bindings/interconnect/qcom,icc.h>
/* UART specific GENI registers */
#define SE_UART_LOOPBACK_CFG 0x22c
#define SE_UART_IO_MACRO_CTRL 0x240
#define SE_UART_TX_TRANS_CFG 0x25c
#define SE_UART_TX_WORD_LEN 0x268
#define SE_UART_TX_STOP_BIT_LEN 0x26c
#define SE_UART_TX_TRANS_LEN 0x270
#define SE_UART_RX_TRANS_CFG 0x280
#define SE_UART_RX_WORD_LEN 0x28c
#define SE_UART_RX_STALE_CNT 0x294
#define SE_UART_TX_PARITY_CFG 0x2a4
#define SE_UART_RX_PARITY_CFG 0x2a8
#define SE_UART_MANUAL_RFR 0x2ac
/* SE_UART_TRANS_CFG */
#define UART_TX_PAR_EN BIT(0)
#define UART_CTS_MASK BIT(1)
/* SE_UART_TX_WORD_LEN */
#define TX_WORD_LEN_MSK GENMASK(9, 0)
/* SE_UART_TX_STOP_BIT_LEN */
#define TX_STOP_BIT_LEN_MSK GENMASK(23, 0)
#define TX_STOP_BIT_LEN_1 0
#define TX_STOP_BIT_LEN_1_5 1
#define TX_STOP_BIT_LEN_2 2
/* SE_UART_TX_TRANS_LEN */
#define TX_TRANS_LEN_MSK GENMASK(23, 0)
/* SE_UART_RX_TRANS_CFG */
#define UART_RX_INS_STATUS_BIT BIT(2)
#define UART_RX_PAR_EN BIT(3)
/* SE_UART_RX_WORD_LEN */
#define RX_WORD_LEN_MASK GENMASK(9, 0)
/* SE_UART_RX_STALE_CNT */
#define RX_STALE_CNT GENMASK(23, 0)
/* SE_UART_TX_PARITY_CFG/RX_PARITY_CFG */
#define PAR_CALC_EN BIT(0)
#define PAR_MODE_MSK GENMASK(2, 1)
#define PAR_MODE_SHFT 1
#define PAR_EVEN 0x00
#define PAR_ODD 0x01
#define PAR_SPACE 0x10
#define PAR_MARK 0x11
/* SE_UART_MANUAL_RFR register fields */
#define UART_MANUAL_RFR_EN BIT(31)
#define UART_RFR_NOT_READY BIT(1)
#define UART_RFR_READY BIT(0)
/* UART M_CMD OP codes */
#define UART_START_TX 0x1
#define UART_START_BREAK 0x4
#define UART_STOP_BREAK 0x5
/* UART S_CMD OP codes */
#define UART_START_READ 0x1
#define UART_PARAM 0x1
#define UART_OVERSAMPLING 32
#define STALE_TIMEOUT 16
#define DEFAULT_BITS_PER_CHAR 10
#define GENI_UART_CONS_PORTS 1
#define GENI_UART_PORTS 3
#define DEF_FIFO_DEPTH_WORDS 16
#define DEF_TX_WM 2
#define DEF_FIFO_WIDTH_BITS 32
#define UART_RX_WM 2
/* SE_UART_LOOPBACK_CFG */
#define RX_TX_SORTED BIT(0)
#define CTS_RTS_SORTED BIT(1)
#define RX_TX_CTS_RTS_SORTED (RX_TX_SORTED | CTS_RTS_SORTED)
/* UART pin swap value */
#define DEFAULT_IO_MACRO_IO0_IO1_MASK GENMASK(3, 0)
#define IO_MACRO_IO0_SEL 0x3
#define DEFAULT_IO_MACRO_IO2_IO3_MASK GENMASK(15, 4)
#define IO_MACRO_IO2_IO3_SWAP 0x4640
/* We always configure 4 bytes per FIFO word */
#define BYTES_PER_FIFO_WORD 4
struct qcom_geni_private_data {
/* NOTE: earlycon port will have NULL here */
struct uart_driver *drv;
u32 poll_cached_bytes;
unsigned int poll_cached_bytes_cnt;
u32 write_cached_bytes;
unsigned int write_cached_bytes_cnt;
};
struct qcom_geni_serial_port {
struct uart_port uport;
struct geni_se se;
const char *name;
u32 tx_fifo_depth;
u32 tx_fifo_width;
u32 rx_fifo_depth;
bool setup;
unsigned long clk_rate;
int (*handle_rx)(struct uart_port *uport, u32 bytes, bool drop);
unsigned int baud;
void *rx_fifo;
u32 loopback;
bool brk;
unsigned int tx_remaining;
int wakeup_irq;
bool rx_tx_swap;
bool cts_rts_swap;
struct qcom_geni_private_data private_data;
};
static const struct uart_ops qcom_geni_console_pops;
static const struct uart_ops qcom_geni_uart_pops;
static struct uart_driver qcom_geni_console_driver;
static struct uart_driver qcom_geni_uart_driver;
static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop);
static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop);
static unsigned int qcom_geni_serial_tx_empty(struct uart_port *port);
static void qcom_geni_serial_stop_rx(struct uart_port *uport);
static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop);
#define to_dev_port(ptr, member) \
container_of(ptr, struct qcom_geni_serial_port, member)
static struct qcom_geni_serial_port qcom_geni_uart_ports[GENI_UART_PORTS] = {
[0] = {
.uport = {
.iotype = UPIO_MEM,
.ops = &qcom_geni_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.line = 0,
},
},
[1] = {
.uport = {
.iotype = UPIO_MEM,
.ops = &qcom_geni_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.line = 1,
},
},
[2] = {
.uport = {
.iotype = UPIO_MEM,
.ops = &qcom_geni_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.line = 2,
},
},
};
static struct qcom_geni_serial_port qcom_geni_console_port = {
.uport = {
.iotype = UPIO_MEM,
.ops = &qcom_geni_console_pops,
.flags = UPF_BOOT_AUTOCONF,
.line = 0,
},
};
static int qcom_geni_serial_request_port(struct uart_port *uport)
{
struct platform_device *pdev = to_platform_device(uport->dev);
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
uport->membase = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(uport->membase))
return PTR_ERR(uport->membase);
port->se.base = uport->membase;
return 0;
}
static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
{
if (cfg_flags & UART_CONFIG_TYPE) {
uport->type = PORT_MSM;
qcom_geni_serial_request_port(uport);
}
}
static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
{
unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
u32 geni_ios;
if (uart_console(uport)) {
mctrl |= TIOCM_CTS;
} else {
geni_ios = readl(uport->membase + SE_GENI_IOS);
if (!(geni_ios & IO2_DATA_IN))
mctrl |= TIOCM_CTS;
}
return mctrl;
}
static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
unsigned int mctrl)
{
u32 uart_manual_rfr = 0;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
if (uart_console(uport))
return;
if (mctrl & TIOCM_LOOP)
port->loopback = RX_TX_CTS_RTS_SORTED;
if (!(mctrl & TIOCM_RTS) && !uport->suspended)
uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
}
static const char *qcom_geni_serial_get_type(struct uart_port *uport)
{
return "MSM";
}
static struct qcom_geni_serial_port *get_port_from_line(int line, bool console)
{
struct qcom_geni_serial_port *port;
int nr_ports = console ? GENI_UART_CONS_PORTS : GENI_UART_PORTS;
if (line < 0 || line >= nr_ports)
return ERR_PTR(-ENXIO);
port = console ? &qcom_geni_console_port : &qcom_geni_uart_ports[line];
return port;
}
static bool qcom_geni_serial_poll_bit(struct uart_port *uport,
int offset, int field, bool set)
{
u32 reg;
struct qcom_geni_serial_port *port;
unsigned int baud;
unsigned int fifo_bits;
unsigned long timeout_us = 20000;
struct qcom_geni_private_data *private_data = uport->private_data;
if (private_data->drv) {
port = to_dev_port(uport, uport);
baud = port->baud;
if (!baud)
baud = 115200;
fifo_bits = port->tx_fifo_depth * port->tx_fifo_width;
/*
* Total polling iterations based on FIFO worth of bytes to be
* sent at current baud. Add a little fluff to the wait.
*/
timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
}
/*
* Use custom implementation instead of readl_poll_atomic since ktimer
* is not ready at the time of early console.
*/
timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
while (timeout_us) {
reg = readl(uport->membase + offset);
if ((bool)(reg & field) == set)
return true;
udelay(10);
timeout_us -= 10;
}
return false;
}
static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size)
{
u32 m_cmd;
writel(xmit_size, uport->membase + SE_UART_TX_TRANS_LEN);
m_cmd = UART_START_TX << M_OPCODE_SHFT;
writel(m_cmd, uport->membase + SE_GENI_M_CMD0);
}
static void qcom_geni_serial_poll_tx_done(struct uart_port *uport)
{
int done;
u32 irq_clear = M_CMD_DONE_EN;
done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_CMD_DONE_EN, true);
if (!done) {
writel(M_GENI_CMD_ABORT, uport->membase +
SE_GENI_M_CMD_CTRL_REG);
irq_clear |= M_CMD_ABORT_EN;
qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_CMD_ABORT_EN, true);
}
writel(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR);
}
static void qcom_geni_serial_abort_rx(struct uart_port *uport)
{
u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
writel(S_GENI_CMD_ABORT, uport->membase + SE_GENI_S_CMD_CTRL_REG);
qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
S_GENI_CMD_ABORT, false);
writel(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
writel(FORCE_DEFAULT, uport->membase + GENI_FORCE_DEFAULT_REG);
}
#ifdef CONFIG_CONSOLE_POLL
static int qcom_geni_serial_get_char(struct uart_port *uport)
{
struct qcom_geni_private_data *private_data = uport->private_data;
u32 status;
u32 word_cnt;
int ret;
if (!private_data->poll_cached_bytes_cnt) {
status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
writel(status, uport->membase + SE_GENI_M_IRQ_CLEAR);
status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
writel(status, uport->membase + SE_GENI_S_IRQ_CLEAR);
status = readl(uport->membase + SE_GENI_RX_FIFO_STATUS);
word_cnt = status & RX_FIFO_WC_MSK;
if (!word_cnt)
return NO_POLL_CHAR;
if (word_cnt == 1 && (status & RX_LAST))
/*
* NOTE: If RX_LAST_BYTE_VALID is 0 it needs to be
* treated as if it was BYTES_PER_FIFO_WORD.
*/
private_data->poll_cached_bytes_cnt =
(status & RX_LAST_BYTE_VALID_MSK) >>
RX_LAST_BYTE_VALID_SHFT;
if (private_data->poll_cached_bytes_cnt == 0)
private_data->poll_cached_bytes_cnt = BYTES_PER_FIFO_WORD;
private_data->poll_cached_bytes =
readl(uport->membase + SE_GENI_RX_FIFOn);
}
private_data->poll_cached_bytes_cnt--;
ret = private_data->poll_cached_bytes & 0xff;
private_data->poll_cached_bytes >>= 8;
return ret;
}
static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
unsigned char c)
{
writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
qcom_geni_serial_setup_tx(uport, 1);
WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_TX_FIFO_WATERMARK_EN, true));
writel(c, uport->membase + SE_GENI_TX_FIFOn);
writel(M_TX_FIFO_WATERMARK_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
qcom_geni_serial_poll_tx_done(uport);
}
#endif
#ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
static void qcom_geni_serial_wr_char(struct uart_port *uport, unsigned char ch)
{
struct qcom_geni_private_data *private_data = uport->private_data;
private_data->write_cached_bytes =
(private_data->write_cached_bytes >> 8) | (ch << 24);
private_data->write_cached_bytes_cnt++;
if (private_data->write_cached_bytes_cnt == BYTES_PER_FIFO_WORD) {
writel(private_data->write_cached_bytes,
uport->membase + SE_GENI_TX_FIFOn);
private_data->write_cached_bytes_cnt = 0;
}
}
static void
__qcom_geni_serial_console_write(struct uart_port *uport, const char *s,
unsigned int count)
{
struct qcom_geni_private_data *private_data = uport->private_data;
int i;
u32 bytes_to_send = count;
for (i = 0; i < count; i++) {
/*
* uart_console_write() adds a carriage return for each newline.
* Account for additional bytes to be written.
*/
if (s[i] == '\n')
bytes_to_send++;
}
writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
qcom_geni_serial_setup_tx(uport, bytes_to_send);
for (i = 0; i < count; ) {
size_t chars_to_write = 0;
size_t avail = DEF_FIFO_DEPTH_WORDS - DEF_TX_WM;
/*
* If the WM bit never set, then the Tx state machine is not
* in a valid state, so break, cancel/abort any existing
* command. Unfortunately the current data being written is
* lost.
*/
if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_TX_FIFO_WATERMARK_EN, true))
break;
chars_to_write = min_t(size_t, count - i, avail / 2);
uart_console_write(uport, s + i, chars_to_write,
qcom_geni_serial_wr_char);
writel(M_TX_FIFO_WATERMARK_EN, uport->membase +
SE_GENI_M_IRQ_CLEAR);
i += chars_to_write;
}
if (private_data->write_cached_bytes_cnt) {
private_data->write_cached_bytes >>= BITS_PER_BYTE *
(BYTES_PER_FIFO_WORD - private_data->write_cached_bytes_cnt);
writel(private_data->write_cached_bytes,
uport->membase + SE_GENI_TX_FIFOn);
private_data->write_cached_bytes_cnt = 0;
}
qcom_geni_serial_poll_tx_done(uport);
}
static void qcom_geni_serial_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_port *uport;
struct qcom_geni_serial_port *port;
bool locked = true;
unsigned long flags;
u32 geni_status;
u32 irq_en;
WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS);
port = get_port_from_line(co->index, true);
if (IS_ERR(port))
return;
uport = &port->uport;
if (oops_in_progress)
locked = spin_trylock_irqsave(&uport->lock, flags);
else
spin_lock_irqsave(&uport->lock, flags);
geni_status = readl(uport->membase + SE_GENI_STATUS);
/* Cancel the current write to log the fault */
if (!locked) {
geni_se_cancel_m_cmd(&port->se);
if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_CMD_CANCEL_EN, true)) {
geni_se_abort_m_cmd(&port->se);
qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_CMD_ABORT_EN, true);
writel(M_CMD_ABORT_EN, uport->membase +
SE_GENI_M_IRQ_CLEAR);
}
writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
} else if ((geni_status & M_GENI_CMD_ACTIVE) && !port->tx_remaining) {
/*
* It seems we can't interrupt existing transfers if all data
* has been sent, in which case we need to look for done first.
*/
qcom_geni_serial_poll_tx_done(uport);
if (!uart_circ_empty(&uport->state->xmit)) {
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
writel(irq_en | M_TX_FIFO_WATERMARK_EN,
uport->membase + SE_GENI_M_IRQ_EN);
}
}
__qcom_geni_serial_console_write(uport, s, count);
if (port->tx_remaining)
qcom_geni_serial_setup_tx(uport, port->tx_remaining);
if (locked)
spin_unlock_irqrestore(&uport->lock, flags);
}
static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
{
u32 i;
unsigned char buf[sizeof(u32)];
struct tty_port *tport;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
tport = &uport->state->port;
for (i = 0; i < bytes; ) {
int c;
int chunk = min_t(int, bytes - i, BYTES_PER_FIFO_WORD);
ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, buf, 1);
i += chunk;
if (drop)
continue;
for (c = 0; c < chunk; c++) {
int sysrq;
uport->icount.rx++;
if (port->brk && buf[c] == 0) {
port->brk = false;
if (uart_handle_break(uport))
continue;
}
sysrq = uart_prepare_sysrq_char(uport, buf[c]);
if (!sysrq)
tty_insert_flip_char(tport, buf[c], TTY_NORMAL);
}
}
if (!drop)
tty_flip_buffer_push(tport);
return 0;
}
#else
static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
{
return -EPERM;
}
#endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
{
struct tty_port *tport;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
u32 num_bytes_pw = port->tx_fifo_width / BITS_PER_BYTE;
u32 words = ALIGN(bytes, num_bytes_pw) / num_bytes_pw;
int ret;
tport = &uport->state->port;
ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, port->rx_fifo, words);
if (drop)
return 0;
ret = tty_insert_flip_string(tport, port->rx_fifo, bytes);
if (ret != bytes) {
dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n",
__func__, ret, bytes);
WARN_ON_ONCE(1);
}
uport->icount.rx += ret;
tty_flip_buffer_push(tport);
return ret;
}
static void qcom_geni_serial_start_tx(struct uart_port *uport)
{
u32 irq_en;
u32 status;
status = readl(uport->membase + SE_GENI_STATUS);
if (status & M_GENI_CMD_ACTIVE)
return;
if (!qcom_geni_serial_tx_empty(uport))
return;
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
}
static void qcom_geni_serial_stop_tx(struct uart_port *uport)
{
u32 irq_en;
u32 status;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
irq_en &= ~(M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN);
writel(0, uport->membase + SE_GENI_TX_WATERMARK_REG);
writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
status = readl(uport->membase + SE_GENI_STATUS);
/* Possible stop tx is called multiple times. */
if (!(status & M_GENI_CMD_ACTIVE))
return;
geni_se_cancel_m_cmd(&port->se);
if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_CMD_CANCEL_EN, true)) {
geni_se_abort_m_cmd(&port->se);
qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
M_CMD_ABORT_EN, true);
writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
}
writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
}
static void qcom_geni_serial_start_rx(struct uart_port *uport)
{
u32 irq_en;
u32 status;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
status = readl(uport->membase + SE_GENI_STATUS);
if (status & S_GENI_CMD_ACTIVE)
qcom_geni_serial_stop_rx(uport);
geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
irq_en |= S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN;
writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
irq_en |= M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN;
writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
}
static void qcom_geni_serial_stop_rx(struct uart_port *uport)
{
u32 irq_en;
u32 status;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
u32 s_irq_status;
irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
irq_en &= ~(S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
irq_en &= ~(M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
status = readl(uport->membase + SE_GENI_STATUS);
/* Possible stop rx is called multiple times. */
if (!(status & S_GENI_CMD_ACTIVE))
return;
geni_se_cancel_s_cmd(&port->se);
qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
S_CMD_CANCEL_EN, true);
/*
* If timeout occurs secondary engine remains active
* and Abort sequence is executed.
*/
s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
/* Flush the Rx buffer */
if (s_irq_status & S_RX_FIFO_LAST_EN)
qcom_geni_serial_handle_rx(uport, true);
writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
status = readl(uport->membase + SE_GENI_STATUS);
if (status & S_GENI_CMD_ACTIVE)
qcom_geni_serial_abort_rx(uport);
}
static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop)
{
u32 status;
u32 word_cnt;
u32 last_word_byte_cnt;
u32 last_word_partial;
u32 total_bytes;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
status = readl(uport->membase + SE_GENI_RX_FIFO_STATUS);
word_cnt = status & RX_FIFO_WC_MSK;
last_word_partial = status & RX_LAST;
last_word_byte_cnt = (status & RX_LAST_BYTE_VALID_MSK) >>
RX_LAST_BYTE_VALID_SHFT;
if (!word_cnt)
return;
total_bytes = BYTES_PER_FIFO_WORD * (word_cnt - 1);
if (last_word_partial && last_word_byte_cnt)
total_bytes += last_word_byte_cnt;
else
total_bytes += BYTES_PER_FIFO_WORD;
port->handle_rx(uport, total_bytes, drop);
}
static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
bool active)
{
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
struct circ_buf *xmit = &uport->state->xmit;
size_t avail;
size_t remaining;
size_t pending;
int i;
u32 status;
u32 irq_en;
unsigned int chunk;
int tail;
status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
/* Complete the current tx command before taking newly added data */
if (active)
pending = port->tx_remaining;
else
pending = uart_circ_chars_pending(xmit);
/* All data has been transmitted and acknowledged as received */
if (!pending && !status && done) {
qcom_geni_serial_stop_tx(uport);
goto out_write_wakeup;
}
avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
avail *= BYTES_PER_FIFO_WORD;
tail = xmit->tail;
chunk = min(avail, pending);
if (!chunk)
goto out_write_wakeup;
if (!port->tx_remaining) {
qcom_geni_serial_setup_tx(uport, pending);
port->tx_remaining = pending;
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
writel(irq_en | M_TX_FIFO_WATERMARK_EN,
uport->membase + SE_GENI_M_IRQ_EN);
}
remaining = chunk;
for (i = 0; i < chunk; ) {
unsigned int tx_bytes;
u8 buf[sizeof(u32)];
int c;
memset(buf, 0, sizeof(buf));
tx_bytes = min_t(size_t, remaining, BYTES_PER_FIFO_WORD);
for (c = 0; c < tx_bytes ; c++) {
buf[c] = xmit->buf[tail++];
tail &= UART_XMIT_SIZE - 1;
}
iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);
i += tx_bytes;
uport->icount.tx += tx_bytes;
remaining -= tx_bytes;
port->tx_remaining -= tx_bytes;
}
xmit->tail = tail;
/*
* The tx fifo watermark is level triggered and latched. Though we had
* cleared it in qcom_geni_serial_isr it will have already reasserted
* so we must clear it again here after our writes.
*/
writel(M_TX_FIFO_WATERMARK_EN,
uport->membase + SE_GENI_M_IRQ_CLEAR);
out_write_wakeup:
if (!port->tx_remaining) {
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
if (irq_en & M_TX_FIFO_WATERMARK_EN)
writel(irq_en & ~M_TX_FIFO_WATERMARK_EN,
uport->membase + SE_GENI_M_IRQ_EN);
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(uport);
}
static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
{
u32 m_irq_en;
u32 m_irq_status;
u32 s_irq_status;
u32 geni_status;
struct uart_port *uport = dev;
bool drop_rx = false;
struct tty_port *tport = &uport->state->port;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
if (uport->suspended)
return IRQ_NONE;
spin_lock(&uport->lock);
m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
geni_status = readl(uport->membase + SE_GENI_STATUS);
m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
if (WARN_ON(m_irq_status & M_ILLEGAL_CMD_EN))
goto out_unlock;
if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
uport->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
}
if (m_irq_status & m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))
qcom_geni_serial_handle_tx(uport, m_irq_status & M_CMD_DONE_EN,
geni_status & M_GENI_CMD_ACTIVE);
if (s_irq_status & S_GP_IRQ_0_EN || s_irq_status & S_GP_IRQ_1_EN) {
if (s_irq_status & S_GP_IRQ_0_EN)
uport->icount.parity++;
drop_rx = true;
} else if (s_irq_status & S_GP_IRQ_2_EN ||
s_irq_status & S_GP_IRQ_3_EN) {
uport->icount.brk++;
port->brk = true;
}
if (s_irq_status & S_RX_FIFO_WATERMARK_EN ||
s_irq_status & S_RX_FIFO_LAST_EN)
qcom_geni_serial_handle_rx(uport, drop_rx);
out_unlock:
uart_unlock_and_check_sysrq(uport);
return IRQ_HANDLED;
}
static int setup_fifos(struct qcom_geni_serial_port *port)
{
struct uart_port *uport;
u32 old_rx_fifo_depth = port->rx_fifo_depth;
uport = &port->uport;
port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se);
port->tx_fifo_width = geni_se_get_tx_fifo_width(&port->se);
port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se);
uport->fifosize =
(port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
if (port->rx_fifo && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) {
port->rx_fifo = devm_krealloc(uport->dev, port->rx_fifo,
port->rx_fifo_depth * sizeof(u32),
GFP_KERNEL);
if (!port->rx_fifo)
return -ENOMEM;
}
return 0;
}
static void qcom_geni_serial_shutdown(struct uart_port *uport)
{
disable_irq(uport->irq);
}
static int qcom_geni_serial_port_setup(struct uart_port *uport)
{
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
u32 proto;
u32 pin_swap;
int ret;
proto = geni_se_read_proto(&port->se);
if (proto != GENI_SE_UART) {
dev_err(uport->dev, "Invalid FW loaded, proto: %d\n", proto);
return -ENXIO;
}
qcom_geni_serial_stop_rx(uport);
ret = setup_fifos(port);
if (ret)
return ret;
writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
pin_swap = readl(uport->membase + SE_UART_IO_MACRO_CTRL);
if (port->rx_tx_swap) {
pin_swap &= ~DEFAULT_IO_MACRO_IO2_IO3_MASK;
pin_swap |= IO_MACRO_IO2_IO3_SWAP;
}
if (port->cts_rts_swap) {
pin_swap &= ~DEFAULT_IO_MACRO_IO0_IO1_MASK;
pin_swap |= IO_MACRO_IO0_SEL;
}
/* Configure this register if RX-TX, CTS-RTS pins are swapped */
if (port->rx_tx_swap || port->cts_rts_swap)
writel(pin_swap, uport->membase + SE_UART_IO_MACRO_CTRL);
/*
* Make an unconditional cancel on the main sequencer to reset
* it else we could end up in data loss scenarios.
*/
if (uart_console(uport))
qcom_geni_serial_poll_tx_done(uport);
geni_se_config_packing(&port->se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
false, true, true);
geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);
geni_se_select_mode(&port->se, GENI_SE_FIFO);
port->setup = true;
return 0;
}
static int qcom_geni_serial_startup(struct uart_port *uport)
{
int ret;
struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
if (!port->setup) {
ret = qcom_geni_serial_port_setup(uport);
if (ret)
return ret;
}
enable_irq(uport->irq);
return 0;
}
static unsigned long find_clk_rate_in_tol(struct clk *clk, unsigned int desired_clk,
unsigned int *clk_div, unsigned int percent_tol)
{
unsigned long freq;
unsigned long div, maxdiv;
u64 mult;
unsigned long offset, abs_tol, achieved;
abs_tol = div_u64((u64)desired_clk * percent_tol, 100);
maxdiv = CLK_DIV_MSK >> CLK_DIV_SHFT;
div = 1;
while (div <= maxdiv) {
mult = (u64)div * desired_clk;
if (mult != (unsigned long)mult)
break;
offset = div * abs_tol;
freq = clk_round_rate(clk, mult - offset);
/* Can only get lower if we're done */
if (freq < mult - offset)
break;
/*
* Re-calculate div in case rounding skipped rates but we
* ended up at a good one, then check for a match.
*/
div = DIV_ROUND_CLOSEST(freq, desired_clk);
achieved = DIV_ROUND_CLOSEST(freq, div);
if (achieved <= desired_clk + abs_tol &&
achieved >= desired_clk - abs_tol) {
*clk_div = div;
return freq;
}
div = DIV_ROUND_UP(freq, desired_clk);
}
return 0;