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linux-next/drivers/tty/serial/etraxfs-uart.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

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// SPDX-License-Identifier: GPL-2.0
#include <linux/module.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/platform_device.h>
#include <linux/serial_core.h>
#include <linux/tty_flip.h>
#include <linux/of.h>
#include <linux/gpio.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <hwregs/ser_defs.h>
#include "serial_mctrl_gpio.h"
#define DRV_NAME "etraxfs-uart"
#define UART_NR CONFIG_ETRAX_SERIAL_PORTS
#define MODIFY_REG(instance, reg, var) \
do { \
if (REG_RD_INT(ser, instance, reg) != \
REG_TYPE_CONV(int, reg_ser_##reg, var)) \
REG_WR(ser, instance, reg, var); \
} while (0)
struct uart_cris_port {
struct uart_port port;
int initialized;
int irq;
void __iomem *regi_ser;
struct mctrl_gpios *gpios;
int write_ongoing;
};
static struct uart_driver etraxfs_uart_driver;
static struct uart_port *console_port;
static int console_baud = 115200;
static struct uart_cris_port *etraxfs_uart_ports[UART_NR];
static void cris_serial_port_init(struct uart_port *port, int line);
static void etraxfs_uart_stop_rx(struct uart_port *port);
static inline void etraxfs_uart_start_tx_bottom(struct uart_port *port);
#ifdef CONFIG_SERIAL_ETRAXFS_CONSOLE
static void
cris_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_cris_port *up;
int i;
reg_ser_r_stat_din stat;
reg_ser_rw_tr_dma_en tr_dma_en, old;
up = etraxfs_uart_ports[co->index];
if (!up)
return;
/* Switch to manual mode. */
tr_dma_en = old = REG_RD(ser, up->regi_ser, rw_tr_dma_en);
if (tr_dma_en.en == regk_ser_yes) {
tr_dma_en.en = regk_ser_no;
REG_WR(ser, up->regi_ser, rw_tr_dma_en, tr_dma_en);
}
/* Send data. */
for (i = 0; i < count; i++) {
/* LF -> CRLF */
if (s[i] == '\n') {
do {
stat = REG_RD(ser, up->regi_ser, r_stat_din);
} while (!stat.tr_rdy);
REG_WR_INT(ser, up->regi_ser, rw_dout, '\r');
}
/* Wait until transmitter is ready and send. */
do {
stat = REG_RD(ser, up->regi_ser, r_stat_din);
} while (!stat.tr_rdy);
REG_WR_INT(ser, up->regi_ser, rw_dout, s[i]);
}
/* Restore mode. */
if (tr_dma_en.en != old.en)
REG_WR(ser, up->regi_ser, rw_tr_dma_en, old);
}
static int __init
cris_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index < 0 || co->index >= UART_NR)
co->index = 0;
port = &etraxfs_uart_ports[co->index]->port;
console_port = port;
co->flags |= CON_CONSDEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
console_baud = baud;
cris_serial_port_init(port, co->index);
uart_set_options(port, co, baud, parity, bits, flow);
return 0;
}
static struct console cris_console = {
.name = "ttyS",
.write = cris_console_write,
.device = uart_console_device,
.setup = cris_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &etraxfs_uart_driver,
};
#endif /* CONFIG_SERIAL_ETRAXFS_CONSOLE */
static struct uart_driver etraxfs_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "serial",
.dev_name = "ttyS",
.major = TTY_MAJOR,
.minor = 64,
.nr = UART_NR,
#ifdef CONFIG_SERIAL_ETRAXFS_CONSOLE
.cons = &cris_console,
#endif /* CONFIG_SERIAL_ETRAXFS_CONSOLE */
};
static inline int crisv32_serial_get_rts(struct uart_cris_port *up)
{
void __iomem *regi_ser = up->regi_ser;
/*
* Return what the user has controlled rts to or
* what the pin is? (if auto_rts is used it differs during tx)
*/
reg_ser_r_stat_din rstat = REG_RD(ser, regi_ser, r_stat_din);
return !(rstat.rts_n == regk_ser_active);
}
/*
* A set = 0 means 3.3V on the pin, bitvalue: 0=active, 1=inactive
* 0=0V , 1=3.3V
*/
static inline void crisv32_serial_set_rts(struct uart_cris_port *up,
int set, int force)
{
void __iomem *regi_ser = up->regi_ser;
unsigned long flags;
reg_ser_rw_rec_ctrl rec_ctrl;
local_irq_save(flags);
rec_ctrl = REG_RD(ser, regi_ser, rw_rec_ctrl);
if (set)
rec_ctrl.rts_n = regk_ser_active;
else
rec_ctrl.rts_n = regk_ser_inactive;
REG_WR(ser, regi_ser, rw_rec_ctrl, rec_ctrl);
local_irq_restore(flags);
}
static inline int crisv32_serial_get_cts(struct uart_cris_port *up)
{
void __iomem *regi_ser = up->regi_ser;
reg_ser_r_stat_din rstat = REG_RD(ser, regi_ser, r_stat_din);
return (rstat.cts_n == regk_ser_active);
}
/*
* Send a single character for XON/XOFF purposes. We do it in this separate
* function instead of the alternative support port.x_char, in the ...start_tx
* function, so we don't mix up this case with possibly enabling transmission
* of queued-up data (in case that's disabled after *receiving* an XOFF or
* negative CTS). This function is used for both DMA and non-DMA case; see HW
* docs specifically blessing sending characters manually when DMA for
* transmission is enabled and running. We may be asked to transmit despite
* the transmitter being disabled by a ..._stop_tx call so we need to enable
* it temporarily but restore the state afterwards.
*/
static void etraxfs_uart_send_xchar(struct uart_port *port, char ch)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
reg_ser_rw_dout dout = { .data = ch };
reg_ser_rw_ack_intr ack_intr = { .tr_rdy = regk_ser_yes };
reg_ser_r_stat_din rstat;
reg_ser_rw_tr_ctrl prev_tr_ctrl, tr_ctrl;
void __iomem *regi_ser = up->regi_ser;
unsigned long flags;
/*
* Wait for tr_rdy in case a character is already being output. Make
* sure we have integrity between the register reads and the writes
* below, but don't busy-wait with interrupts off and the port lock
* taken.
*/
spin_lock_irqsave(&port->lock, flags);
do {
spin_unlock_irqrestore(&port->lock, flags);
spin_lock_irqsave(&port->lock, flags);
prev_tr_ctrl = tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl);
rstat = REG_RD(ser, regi_ser, r_stat_din);
} while (!rstat.tr_rdy);
/*
* Ack an interrupt if one was just issued for the previous character
* that was output. This is required for non-DMA as the interrupt is
* used as the only indicator that the transmitter is ready and it
* isn't while this x_char is being transmitted.
*/
REG_WR(ser, regi_ser, rw_ack_intr, ack_intr);
/* Enable the transmitter in case it was disabled. */
tr_ctrl.stop = 0;
REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl);
/*
* Finally, send the blessed character; nothing should stop it now,
* except for an xoff-detected state, which we'll handle below.
*/
REG_WR(ser, regi_ser, rw_dout, dout);
up->port.icount.tx++;
/* There might be an xoff state to clear. */
rstat = REG_RD(ser, up->regi_ser, r_stat_din);
/*
* Clear any xoff state that *may* have been there to
* inhibit transmission of the character.
*/
if (rstat.xoff_detect) {
reg_ser_rw_xoff_clr xoff_clr = { .clr = 1 };
reg_ser_rw_tr_dma_en tr_dma_en;
REG_WR(ser, regi_ser, rw_xoff_clr, xoff_clr);
tr_dma_en = REG_RD(ser, regi_ser, rw_tr_dma_en);
/*
* If we had an xoff state but cleared it, instead sneak in a
* disabled state for the transmitter, after the character we
* sent. Thus we keep the port disabled, just as if the xoff
* state was still in effect (or actually, as if stop_tx had
* been called, as we stop DMA too).
*/
prev_tr_ctrl.stop = 1;
tr_dma_en.en = 0;
REG_WR(ser, regi_ser, rw_tr_dma_en, tr_dma_en);
}
/* Restore "previous" enabled/disabled state of the transmitter. */
REG_WR(ser, regi_ser, rw_tr_ctrl, prev_tr_ctrl);
spin_unlock_irqrestore(&port->lock, flags);
}
/*
* Do not spin_lock_irqsave or disable interrupts by other means here; it's
* already done by the caller.
*/
static void etraxfs_uart_start_tx(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
/* we have already done below if a write is ongoing */
if (up->write_ongoing)
return;
/* Signal that write is ongoing */
up->write_ongoing = 1;
etraxfs_uart_start_tx_bottom(port);
}
static inline void etraxfs_uart_start_tx_bottom(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
void __iomem *regi_ser = up->regi_ser;
reg_ser_rw_tr_ctrl tr_ctrl;
reg_ser_rw_intr_mask intr_mask;
tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl);
tr_ctrl.stop = regk_ser_no;
REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl);
intr_mask = REG_RD(ser, regi_ser, rw_intr_mask);
intr_mask.tr_rdy = regk_ser_yes;
REG_WR(ser, regi_ser, rw_intr_mask, intr_mask);
}
/*
* This function handles both the DMA and non-DMA case by ordering the
* transmitter to stop of after the current character. We don't need to wait
* for any such character to be completely transmitted; we do that where it
* matters, like in etraxfs_uart_set_termios. Don't busy-wait here; see
* Documentation/serial/driver: this function is called within
* spin_lock_irq{,save} and thus separate ones would be disastrous (when SMP).
* There's no documented need to set the txd pin to any particular value;
* break setting is controlled solely by etraxfs_uart_break_ctl.
*/
static void etraxfs_uart_stop_tx(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
void __iomem *regi_ser = up->regi_ser;
reg_ser_rw_tr_ctrl tr_ctrl;
reg_ser_rw_intr_mask intr_mask;
reg_ser_rw_tr_dma_en tr_dma_en = {0};
reg_ser_rw_xoff_clr xoff_clr = {0};
/*
* For the non-DMA case, we'd get a tr_rdy interrupt that we're not
* interested in as we're not transmitting any characters. For the
* DMA case, that interrupt is already turned off, but no reason to
* waste code on conditionals here.
*/
intr_mask = REG_RD(ser, regi_ser, rw_intr_mask);
intr_mask.tr_rdy = regk_ser_no;
REG_WR(ser, regi_ser, rw_intr_mask, intr_mask);
tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl);
tr_ctrl.stop = 1;
REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl);
/*
* Always clear possible hardware xoff-detected state here, no need to
* unnecessary consider mctrl settings and when they change. We clear
* it here rather than in start_tx: both functions are called as the
* effect of XOFF processing, but start_tx is also called when upper
* levels tell the driver that there are more characters to send, so
* avoid adding code there.
*/
xoff_clr.clr = 1;
REG_WR(ser, regi_ser, rw_xoff_clr, xoff_clr);
/*
* Disable transmitter DMA, so that if we're in XON/XOFF, we can send
* those single characters without also giving go-ahead for queued up
* DMA data.
*/
tr_dma_en.en = 0;
REG_WR(ser, regi_ser, rw_tr_dma_en, tr_dma_en);
/*
* Make sure that write_ongoing is reset when stopping tx.
*/
up->write_ongoing = 0;
}
static void etraxfs_uart_stop_rx(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
void __iomem *regi_ser = up->regi_ser;
reg_ser_rw_rec_ctrl rec_ctrl = REG_RD(ser, regi_ser, rw_rec_ctrl);
rec_ctrl.en = regk_ser_no;
REG_WR(ser, regi_ser, rw_rec_ctrl, rec_ctrl);
}
static unsigned int etraxfs_uart_tx_empty(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
unsigned long flags;
unsigned int ret;
reg_ser_r_stat_din rstat = {0};
spin_lock_irqsave(&up->port.lock, flags);
rstat = REG_RD(ser, up->regi_ser, r_stat_din);
ret = rstat.tr_empty ? TIOCSER_TEMT : 0;
spin_unlock_irqrestore(&up->port.lock, flags);
return ret;
}
static unsigned int etraxfs_uart_get_mctrl(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
unsigned int ret;
ret = 0;
if (crisv32_serial_get_rts(up))
ret |= TIOCM_RTS;
if (crisv32_serial_get_cts(up))
ret |= TIOCM_CTS;
return mctrl_gpio_get(up->gpios, &ret);
}
static void etraxfs_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
crisv32_serial_set_rts(up, mctrl & TIOCM_RTS ? 1 : 0, 0);
mctrl_gpio_set(up->gpios, mctrl);
}
static void etraxfs_uart_break_ctl(struct uart_port *port, int break_state)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
unsigned long flags;
reg_ser_rw_tr_ctrl tr_ctrl;
reg_ser_rw_tr_dma_en tr_dma_en;
reg_ser_rw_intr_mask intr_mask;
spin_lock_irqsave(&up->port.lock, flags);
tr_ctrl = REG_RD(ser, up->regi_ser, rw_tr_ctrl);
tr_dma_en = REG_RD(ser, up->regi_ser, rw_tr_dma_en);
intr_mask = REG_RD(ser, up->regi_ser, rw_intr_mask);
if (break_state != 0) { /* Send break */
/*
* We need to disable DMA (if used) or tr_rdy interrupts if no
* DMA. No need to make this conditional on use of DMA;
* disabling will be a no-op for the other mode.
*/
intr_mask.tr_rdy = regk_ser_no;
tr_dma_en.en = 0;
/*
* Stop transmission and set the txd pin to 0 after the
* current character. The txd setting will take effect after
* any current transmission has completed.
*/
tr_ctrl.stop = 1;
tr_ctrl.txd = 0;
} else {
/* Re-enable the serial interrupt. */
intr_mask.tr_rdy = regk_ser_yes;
tr_ctrl.stop = 0;
tr_ctrl.txd = 1;
}
REG_WR(ser, up->regi_ser, rw_tr_ctrl, tr_ctrl);
REG_WR(ser, up->regi_ser, rw_tr_dma_en, tr_dma_en);
REG_WR(ser, up->regi_ser, rw_intr_mask, intr_mask);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static void
transmit_chars_no_dma(struct uart_cris_port *up)
{
int max_count;
struct circ_buf *xmit = &up->port.state->xmit;
void __iomem *regi_ser = up->regi_ser;
reg_ser_r_stat_din rstat;
reg_ser_rw_ack_intr ack_intr = { .tr_rdy = regk_ser_yes };
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
/* No more to send, so disable the interrupt. */
reg_ser_rw_intr_mask intr_mask;
intr_mask = REG_RD(ser, regi_ser, rw_intr_mask);
intr_mask.tr_rdy = 0;
intr_mask.tr_empty = 0;
REG_WR(ser, regi_ser, rw_intr_mask, intr_mask);
up->write_ongoing = 0;
return;
}
/* If the serport is fast, we send up to max_count bytes before
exiting the loop. */
max_count = 64;
do {
reg_ser_rw_dout dout = { .data = xmit->buf[xmit->tail] };
REG_WR(ser, regi_ser, rw_dout, dout);
REG_WR(ser, regi_ser, rw_ack_intr, ack_intr);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
up->port.icount.tx++;
if (xmit->head == xmit->tail)
break;
rstat = REG_RD(ser, regi_ser, r_stat_din);
} while ((--max_count > 0) && rstat.tr_rdy);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
}
static void receive_chars_no_dma(struct uart_cris_port *up)
{
reg_ser_rs_stat_din stat_din;
reg_ser_r_stat_din rstat;
struct tty_port *port;
struct uart_icount *icount;
int max_count = 16;
char flag;
reg_ser_rw_ack_intr ack_intr = { 0 };
rstat = REG_RD(ser, up->regi_ser, r_stat_din);
icount = &up->port.icount;
port = &up->port.state->port;
do {
stat_din = REG_RD(ser, up->regi_ser, rs_stat_din);
flag = TTY_NORMAL;
ack_intr.dav = 1;
REG_WR(ser, up->regi_ser, rw_ack_intr, ack_intr);
icount->rx++;
if (stat_din.framing_err | stat_din.par_err | stat_din.orun) {
if (stat_din.data == 0x00 &&
stat_din.framing_err) {
/* Most likely a break. */
flag = TTY_BREAK;
icount->brk++;
} else if (stat_din.par_err) {
flag = TTY_PARITY;
icount->parity++;
} else if (stat_din.orun) {
flag = TTY_OVERRUN;
icount->overrun++;
} else if (stat_din.framing_err) {
flag = TTY_FRAME;
icount->frame++;
}
}
/*
* If this becomes important, we probably *could* handle this
* gracefully by keeping track of the unhandled character.
*/
if (!tty_insert_flip_char(port, stat_din.data, flag))
panic("%s: No tty buffer space", __func__);
rstat = REG_RD(ser, up->regi_ser, r_stat_din);
} while (rstat.dav && (max_count-- > 0));
spin_unlock(&up->port.lock);
tty_flip_buffer_push(port);
spin_lock(&up->port.lock);
}
static irqreturn_t
ser_interrupt(int irq, void *dev_id)
{
struct uart_cris_port *up = (struct uart_cris_port *)dev_id;
void __iomem *regi_ser;
int handled = 0;
spin_lock(&up->port.lock);
regi_ser = up->regi_ser;
if (regi_ser) {
reg_ser_r_masked_intr masked_intr;
masked_intr = REG_RD(ser, regi_ser, r_masked_intr);
/*
* Check what interrupts are active before taking
* actions. If DMA is used the interrupt shouldn't
* be enabled.
*/
if (masked_intr.dav) {
receive_chars_no_dma(up);
handled = 1;
}
if (masked_intr.tr_rdy) {
transmit_chars_no_dma(up);
handled = 1;
}
}
spin_unlock(&up->port.lock);
return IRQ_RETVAL(handled);
}
#ifdef CONFIG_CONSOLE_POLL
static int etraxfs_uart_get_poll_char(struct uart_port *port)
{
reg_ser_rs_stat_din stat;
reg_ser_rw_ack_intr ack_intr = { 0 };
struct uart_cris_port *up = (struct uart_cris_port *)port;
do {
stat = REG_RD(ser, up->regi_ser, rs_stat_din);
} while (!stat.dav);
/* Ack the data_avail interrupt. */
ack_intr.dav = 1;
REG_WR(ser, up->regi_ser, rw_ack_intr, ack_intr);
return stat.data;
}
static void etraxfs_uart_put_poll_char(struct uart_port *port,
unsigned char c)
{
reg_ser_r_stat_din stat;
struct uart_cris_port *up = (struct uart_cris_port *)port;
do {
stat = REG_RD(ser, up->regi_ser, r_stat_din);
} while (!stat.tr_rdy);
REG_WR_INT(ser, up->regi_ser, rw_dout, c);
}
#endif /* CONFIG_CONSOLE_POLL */
static int etraxfs_uart_startup(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
unsigned long flags;
reg_ser_rw_intr_mask ser_intr_mask = {0};
ser_intr_mask.dav = regk_ser_yes;
if (request_irq(etraxfs_uart_ports[port->line]->irq, ser_interrupt,
0, DRV_NAME, etraxfs_uart_ports[port->line]))
panic("irq ser%d", port->line);
spin_lock_irqsave(&up->port.lock, flags);
REG_WR(ser, up->regi_ser, rw_intr_mask, ser_intr_mask);
etraxfs_uart_set_mctrl(&up->port, up->port.mctrl);
spin_unlock_irqrestore(&up->port.lock, flags);
return 0;
}
static void etraxfs_uart_shutdown(struct uart_port *port)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
etraxfs_uart_stop_tx(port);
etraxfs_uart_stop_rx(port);
free_irq(etraxfs_uart_ports[port->line]->irq,
etraxfs_uart_ports[port->line]);
etraxfs_uart_set_mctrl(&up->port, up->port.mctrl);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static void
etraxfs_uart_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
unsigned long flags;
reg_ser_rw_xoff xoff;
reg_ser_rw_xoff_clr xoff_clr = {0};
reg_ser_rw_tr_ctrl tx_ctrl = {0};
reg_ser_rw_tr_dma_en tx_dma_en = {0};
reg_ser_rw_rec_ctrl rx_ctrl = {0};
reg_ser_rw_tr_baud_div tx_baud_div = {0};
reg_ser_rw_rec_baud_div rx_baud_div = {0};
int baud;
if (old &&
termios->c_cflag == old->c_cflag &&
termios->c_iflag == old->c_iflag)
return;
/* Tx: 8 bit, no/even parity, 1 stop bit, no cts. */
tx_ctrl.base_freq = regk_ser_f29_493;
tx_ctrl.en = 0;
tx_ctrl.stop = 0;
tx_ctrl.auto_rts = regk_ser_no;
tx_ctrl.txd = 1;
tx_ctrl.auto_cts = 0;
/* Rx: 8 bit, no/even parity. */
rx_ctrl.dma_err = regk_ser_stop;
rx_ctrl.sampling = regk_ser_majority;
rx_ctrl.timeout = 1;
rx_ctrl.rts_n = regk_ser_inactive;
/* Common for tx and rx: 8N1. */
tx_ctrl.data_bits = regk_ser_bits8;
rx_ctrl.data_bits = regk_ser_bits8;
tx_ctrl.par = regk_ser_even;
rx_ctrl.par = regk_ser_even;
tx_ctrl.par_en = regk_ser_no;
rx_ctrl.par_en = regk_ser_no;
tx_ctrl.stop_bits = regk_ser_bits1;
/*
* Change baud-rate and write it to the hardware.
*
* baud_clock = base_freq / (divisor*8)
* divisor = base_freq / (baud_clock * 8)
* base_freq is either:
* off, ext, 29.493MHz, 32.000 MHz, 32.768 MHz or 100 MHz
* 20.493MHz is used for standard baudrates
*/
/*
* For the console port we keep the original baudrate here. Not very
* beautiful.
*/
if ((port != console_port) || old)
baud = uart_get_baud_rate(port, termios, old, 0,
port->uartclk / 8);
else
baud = console_baud;
tx_baud_div.div = 29493000 / (8 * baud);
/* Rx uses same as tx. */
rx_baud_div.div = tx_baud_div.div;
rx_ctrl.base_freq = tx_ctrl.base_freq;
if ((termios->c_cflag & CSIZE) == CS7) {
/* Set 7 bit mode. */
tx_ctrl.data_bits = regk_ser_bits7;
rx_ctrl.data_bits = regk_ser_bits7;
}
if (termios->c_cflag & CSTOPB) {
/* Set 2 stop bit mode. */
tx_ctrl.stop_bits = regk_ser_bits2;
}
if (termios->c_cflag & PARENB) {
/* Enable parity. */
tx_ctrl.par_en = regk_ser_yes;
rx_ctrl.par_en = regk_ser_yes;
}
if (termios->c_cflag & CMSPAR) {
if (termios->c_cflag & PARODD) {
/* Set mark parity if PARODD and CMSPAR. */
tx_ctrl.par = regk_ser_mark;
rx_ctrl.par = regk_ser_mark;
} else {
tx_ctrl.par = regk_ser_space;
rx_ctrl.par = regk_ser_space;
}
} else {
if (termios->c_cflag & PARODD) {
/* Set odd parity. */
tx_ctrl.par = regk_ser_odd;
rx_ctrl.par = regk_ser_odd;
}
}
if (termios->c_cflag & CRTSCTS) {
/* Enable automatic CTS handling. */
tx_ctrl.auto_cts = regk_ser_yes;
}
/* Make sure the tx and rx are enabled. */
tx_ctrl.en = regk_ser_yes;
rx_ctrl.en = regk_ser_yes;
spin_lock_irqsave(&port->lock, flags);
tx_dma_en.en = 0;
REG_WR(ser, up->regi_ser, rw_tr_dma_en, tx_dma_en);
/* Actually write the control regs (if modified) to the hardware. */
uart_update_timeout(port, termios->c_cflag, port->uartclk/8);
MODIFY_REG(up->regi_ser, rw_rec_baud_div, rx_baud_div);
MODIFY_REG(up->regi_ser, rw_rec_ctrl, rx_ctrl);
MODIFY_REG(up->regi_ser, rw_tr_baud_div, tx_baud_div);
MODIFY_REG(up->regi_ser, rw_tr_ctrl, tx_ctrl);
tx_dma_en.en = 0;
REG_WR(ser, up->regi_ser, rw_tr_dma_en, tx_dma_en);
xoff = REG_RD(ser, up->regi_ser, rw_xoff);
if (up->port.state && up->port.state->port.tty &&
(up->port.state->port.tty->termios.c_iflag & IXON)) {
xoff.chr = STOP_CHAR(up->port.state->port.tty);
xoff.automatic = regk_ser_yes;
} else
xoff.automatic = regk_ser_no;
MODIFY_REG(up->regi_ser, rw_xoff, xoff);
/*
* Make sure we don't start in an automatically shut-off state due to
* a previous early exit.
*/
xoff_clr.clr = 1;
REG_WR(ser, up->regi_ser, rw_xoff_clr, xoff_clr);
etraxfs_uart_set_mctrl(&up->port, up->port.mctrl);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static const char *
etraxfs_uart_type(struct uart_port *port)
{
return "CRISv32";
}
static void etraxfs_uart_release_port(struct uart_port *port)
{
}
static int etraxfs_uart_request_port(struct uart_port *port)
{
return 0;
}
static void etraxfs_uart_config_port(struct uart_port *port, int flags)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
up->port.type = PORT_CRIS;
}
static const struct uart_ops etraxfs_uart_pops = {
.tx_empty = etraxfs_uart_tx_empty,
.set_mctrl = etraxfs_uart_set_mctrl,
.get_mctrl = etraxfs_uart_get_mctrl,
.stop_tx = etraxfs_uart_stop_tx,
.start_tx = etraxfs_uart_start_tx,
.send_xchar = etraxfs_uart_send_xchar,
.stop_rx = etraxfs_uart_stop_rx,
.break_ctl = etraxfs_uart_break_ctl,
.startup = etraxfs_uart_startup,
.shutdown = etraxfs_uart_shutdown,
.set_termios = etraxfs_uart_set_termios,
.type = etraxfs_uart_type,
.release_port = etraxfs_uart_release_port,
.request_port = etraxfs_uart_request_port,
.config_port = etraxfs_uart_config_port,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = etraxfs_uart_get_poll_char,
.poll_put_char = etraxfs_uart_put_poll_char,
#endif
};
static void cris_serial_port_init(struct uart_port *port, int line)
{
struct uart_cris_port *up = (struct uart_cris_port *)port;
if (up->initialized)
return;
up->initialized = 1;
port->line = line;
spin_lock_init(&port->lock);
port->ops = &etraxfs_uart_pops;
port->irq = up->irq;
port->iobase = (unsigned long) up->regi_ser;
port->uartclk = 29493000;
/*
* We can't fit any more than 255 here (unsigned char), though
* actually UART_XMIT_SIZE characters could be pending output.
* At time of this writing, the definition of "fifosize" is here the
* amount of characters that can be pending output after a start_tx call
* until tx_empty returns 1: see serial_core.c:uart_wait_until_sent.
* This matters for timeout calculations unfortunately, but keeping
* larger amounts at the DMA wouldn't win much so let's just play nice.
*/
port->fifosize = 255;
port->flags = UPF_BOOT_AUTOCONF;
}
static int etraxfs_uart_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct uart_cris_port *up;
int dev_id;
if (!np)
return -ENODEV;
dev_id = of_alias_get_id(np, "serial");
if (dev_id < 0)
dev_id = 0;
if (dev_id >= UART_NR)
return -EINVAL;
if (etraxfs_uart_ports[dev_id])
return -EBUSY;
up = devm_kzalloc(&pdev->dev, sizeof(struct uart_cris_port),
GFP_KERNEL);
if (!up)
return -ENOMEM;
up->irq = irq_of_parse_and_map(np, 0);
up->regi_ser = of_iomap(np, 0);
up->port.dev = &pdev->dev;
up->gpios = mctrl_gpio_init_noauto(&pdev->dev, 0);
if (IS_ERR(up->gpios))
return PTR_ERR(up->gpios);
cris_serial_port_init(&up->port, dev_id);
etraxfs_uart_ports[dev_id] = up;
platform_set_drvdata(pdev, &up->port);
uart_add_one_port(&etraxfs_uart_driver, &up->port);
return 0;
}
static int etraxfs_uart_remove(struct platform_device *pdev)
{
struct uart_port *port;
port = platform_get_drvdata(pdev);
uart_remove_one_port(&etraxfs_uart_driver, port);
etraxfs_uart_ports[port->line] = NULL;
return 0;
}
static const struct of_device_id etraxfs_uart_dt_ids[] = {
{ .compatible = "axis,etraxfs-uart" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, etraxfs_uart_dt_ids);
static struct platform_driver etraxfs_uart_platform_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = of_match_ptr(etraxfs_uart_dt_ids),
},
.probe = etraxfs_uart_probe,
.remove = etraxfs_uart_remove,
};
static int __init etraxfs_uart_init(void)
{
int ret;
ret = uart_register_driver(&etraxfs_uart_driver);
if (ret)
return ret;
ret = platform_driver_register(&etraxfs_uart_platform_driver);
if (ret)
uart_unregister_driver(&etraxfs_uart_driver);
return ret;
}
static void __exit etraxfs_uart_exit(void)
{
platform_driver_unregister(&etraxfs_uart_platform_driver);
uart_unregister_driver(&etraxfs_uart_driver);
}
module_init(etraxfs_uart_init);
module_exit(etraxfs_uart_exit);
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