When nr_uarts was set to 0 (via config or 8250_core.nr_uarts), we crash
early on x86 because serial8250_isa_init_ports dereferences base_ops
which remains NULL. In fact, there is nothing to do for all the callers
of serial8250_isa_init_ports if there are no uarts.

Based on suggestions by Peter Hurley.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Staticize symbols not exported and not used outside of file.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The code it refers to was removed in commit b545e4f4 ("serial:
sh-sci: Compute overrun_bit without using baud rate algo").
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

error_mask is the union of all error indicating bits in the SCxSR
register, while overrun_mask may apply to a different register (SCLSR),
depending on the SCI variant.

Hence overrun_mask should only be ORed into error_mask if it applies to
the SCxSR register.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The various SCI implementations use 3 different methods to signal
overrun errors:
  - Bit SCI_ORER in register SCxSR on SCI,
  - Bit SCIFA_ORER in register SCxSR on SCIFA and SCIFB, and SCIF on
    SH7705/SH7720/SH7721,
  - Bit SCLSR_ORER in (optional!) register SCLSR on (H)SCIF.

However:
  1. sci_handle_fifo_overrun()
       a. handles (H)SCIF and SCIFA/SCIFB only,
       b. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
  2. sci_mpxed_interrupt()
       a. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
       b. ignores that not all SCIFs have the SCLSR register, causing
	  "Invalid register access" WARN()ings.

To fix the above:
  1. Determine and store the correct register enum during
     initialization,
  2. Replace the duplicated buggy switch statements by using the stored
     register enum,
  3. Add the missing existence check to  sci_mpxed_interrupt().
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the missing overrun bit definition for (H)SCIF.
Replace overrun_bit by overrun_mask, so we can use the existing
defines instead of hardcoded values.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the missing overrun error bit in SCxSR on SCIFA/SCIFB and SCIF on
SH7705/SH7720/SH7721.
Document what the corresponding bit(s) on plain SCIF are used for.
Sort the components of SCIF_DEFAULT_ERROR_MASK by reverse definition
order.

Replace the hardcoded values in the SCxSR_*_CLEAR macros by proper
defines. Use bit masks (negations of sets of bits) to make it more
obvious which bits are being cleared.

Assembler output (on sh) was compared before and after this commit:
  - For the first branch of the big "#if defined(...) || ..." construct,
    the code has changed slightly, as 32-bit bitmasks can be loaded in a
    single instruction, unlike the old large 16-bit constants (the SCxSR
    register is 16 bit, so we don't care about the top 16 bits),
  - For the second branch, the generated code is identical.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the register definitions for the Serial Port Control and Data
Registers on SCIFA/SCIFB, which are needed for RTS/CTS pin control.

Extracted from patches by Magnus Damm <damm+renesas@opensource.se>.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the missing register bit definitions to set the RTS pin and read the
CTS pin on (H)SCIF.

Extracted from patches by Magnus Damm <damm+renesas@opensource.se>.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move private register definitions and enums from the public
<linux/serial_sci.h> header file to the driver private "sh-sci.h" header
file.

The common Serial Control Register definitions are left in the public
header file, as they're needed to fill in plat_sci_port.scscr on legacy
systems not using DT.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Pat Gefre <pfg@sgi.com>
CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Pat Gefre <pfg@sgi.com>
CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
CC: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
CC: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Mikael Starvik <starvik@axis.com>
CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
CC: Takashi Iwai <tiwai@suse.de>
CC: Imre Deak <imre.deak@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be doing assignments within an if () block
so fix up the code to not do this.

change was created using Coccinelle.

CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In SiRF platform, there are different fifo size of uart and usp,
with the fifosize configuration changes in different chips, we
can not use port line to decide how to check FIFO full,empty and
level.

There is a direct mapping between FIFO HW register layout with
fifo size, so move to use fifosize as the input to check fifo
status.
Signed-off-by: NQipan Li <Qipan.Li@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In different platform of SiRF SoCs, there is no same uart and usp-uart
numbers, it is not convenient to use hard-coded ports array and port
lines.

here we drop the hard-coded ports table , and drop "cell-index". then
move to use alias id to get line.

for example:
	aliases {
		serial0 = &uart0;
		serial1 = &uart1;
		serial2 = &uart2;
		serial3 = &uart3;
		serial4 = &uart4;
		serial5 = &uart5;
		serial6 = &uart6;
		serial9 = &usp2;
	};

at the same, enlarge the max port number according to the chip with the most
UART.
Signed-off-by: NQipan Li <Qipan.Li@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add 8250 MTK UART driver to support earlycon device tree.
Earlycon take effect by
  add "earlycon" in kernel boot argument
  add "linux,sdtout-path" property in device tree file
Signed-off-by: NEddie Huang <eddie.huang@mediatek.com>
Tested-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

8250-like uart driver may call early_serial8250_setup to
reuse 8250_early.c character output function.
Signed-off-by: NEddie Huang <eddie.huang@mediatek.com>
Tested-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The mtk 8250 needs two clocks, one for providing the baudrate and
one that needs to be enabled for register accesses. The latter has
not been supported, this patch adds support for it. It is optional
for now since not all SoCs provide a bus clock.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The pm_runtime callbacks already enable and disable the device.
Use them in probe() and remove() instead of duplicating the
code. This allows us to concentrate more code for enabling/disabling
the UART in a single place.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When a struct device * is present clk_get should be used rather
than of_clk_get. Use the devm variant of this function to be able to
drop the clk_put in the error and remove pathes. While at it fix
a wrong error message.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the driver has probed successfully the clk pointer is always valid,
so no need to test for it.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function meson_uart_release_port() inappropriately try to
iounmap() a resource managed by devm_ioremap_nocache().
The function meson_uart_release_port() maybe called by uart_ioctl()
that means meson_uart_release_port() is not called from within a
probe or remove function, for safety, I convert iounmap() to
devm_iounmap().
Signed-off-by: NFiro Yang <firogm@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The rx_running flag should show if DMA is currently active. However
there is a window between when the flag is set/cleared and when
the DMA is started/stopped. Because the flag is queried from both
hard and soft irq contexts, the driver can make incorrect
decisions and do things like start a DMA transfer using a buffer
that is already setup to be used for a DMA transfer.

This patch adds a spinlock to synchronize the rx_running flag and
close the above mentioned window.
Signed-off-by: NJohn Ogness <john.ogness@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>