spi: dw-bt1: Use helper function devm_clk_get_enabled()

Since commit 7ef9651e9792 ("clk: Provide new devm_clk helpers for prepared
and enabled clocks"), devm_clk_get() and clk_prepare_enable() can now be
replaced by devm_clk_get_enabled() when driver enables (and possibly
prepares) the clocks for the whole lifetime of the device. Moreover, it is
no longer necessary to unprepare and disable the clocks explicitly.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Link: https://lore.kernel.org/r/20230823133938.1359106-12-lizetao1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-bt1: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230303172041.2103336-22-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Fix PM disable depth imbalance in dw_spi_bt1_probe

The pm_runtime_enable will increase power disable depth. Thus
a pairing decrement is needed on the error handling path to
keep it balanced according to context.

Fixes:abf00907538e2 ("spi: dw: Add Baikal-T1 SPI Controller glue driver")

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20220924121310.78331-3-zhangqilong3@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Put the driver entities naming in order

Mostly due to a long driver history it's methods and macro names look a
bit messy. In particularly that concerns the code their prefixes. A
biggest part of the driver functions and macros have got the dw_spi/DW_SPI
prefixes. But there are some entities which have been just
"spi_/SPI_"-prefixed. Especially that concerns the CSR and their fields
macro definitions. It makes the code harder to comprehend since such
methods and macros can be easily confused with the global SPI-subsystem
exports. In this case the only possible way to more or less quickly
distinguish one naming space from another is either by context or by the
argument type, which most of the times isn't that easy anyway. In addition
to that a new DW SSI IP-core support has been added in the framework of
commit e539f435cb9c ("spi: dw: Add support for DesignWare DWC_ssi"), which
introduced a new set or macro-prefixes to describe CTRLR0-specific fields
and worsen the situation. Finally there are methods with
no DW SPI driver-reference prefix at all, that make the code reading even
harder. So in order to ease the driver hacking let's bring the code naming
to a common base:
1) Each method is supposed to have "dw_spi_" prefix so to be easily
distinguished from the kernel API, e.g. SPI-subsystem methods and macros.
(Exception is the local implementation of the readl/writel methods since
being just the regspace accessors.)
2) Each generically used macro should have DW_SPI_-prefix thus being
easily comprehended as the local driver definition.
3) DW APB SSI and DW SSI specific macros should have prefixes as DW_PSSI_
and DW_HSSI_ respectively so referring to the system buses they support
(APB and AHB similarly to the DT clocks naming like pclk, hclk).

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-4-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add a symbols namespace for the core module

The exported from the DW SPI driver core/DMA symbols are only used by the
spi-dw-{mmio,pci,bt1}.o objects. Add these symbols to a separate
namespace then and make sure the depended modules have it imported.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-2-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Avoid stack content exposure

Since "data" is u32, &data is a "u32 *" type, which means pointer math
will move in u32-sized steps. This was meant to be a byte offset, so
cast &data to "char *" to aim the copy into the correct location.

Seen with -Warray-bounds (and found by Coverity):

In file included from ./include/linux/string.h:269,
from ./arch/powerpc/include/asm/paca.h:15,
from ./arch/powerpc/include/asm/current.h:13,
from ./include/linux/mutex.h:14,
from ./include/linux/notifier.h:14,
from ./include/linux/clk.h:14,
from drivers/spi/spi-dw-bt1.c:12:
In function 'memcpy',
inlined from 'dw_spi_bt1_dirmap_copy_from_map' at drivers/spi/spi-dw-bt1.c:87:3:
./include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset 4 is out of the bounds [0, 4] of object 'data' with type 'u32' {aka 'unsigned int'} [-Warray-bounds]
20 | #define __underlying_memcpy __builtin_memcpy
| ^
./include/linux/fortify-string.h:191:9: note: in expansion of macro '__underlying_memcpy'
191 | return __underlying_memcpy(p, q, size);
| ^~~~~~~~~~~~~~~~~~~
drivers/spi/spi-dw-bt1.c: In function 'dw_spi_bt1_dirmap_copy_from_map':
drivers/spi/spi-dw-bt1.c:77:6: note: 'data' declared here
77 | u32 data;
| ^~~~

Addresses-Coverity: CID 1497771 Out-of-bounds access
Fixes: abf00907538e ("spi: dw: Add Baikal-T1 SPI Controller glue driver")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20210211203714.1929862-1-keescook@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Fix error return code in dw_spi_bt1_probe()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: abf00907538e ("spi: dw: Add Baikal-T1 SPI Controller glue driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/1607071357-33378-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: fixed missing resource_size

fixed the coccicheck:
drivers/spi/spi-dw-bt1.c:220:27-30: ERROR: Missing
resource_size with mem.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/1606114975-31362-1-git-send-email-tiantao6@hisilicon.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add Baikal-T1 SPI Controller glue driver

Baikal-T1 is equipped with three DW APB SSI-based MMIO SPI controllers.
Two of them are pretty much normal: with IRQ, DMA, FIFOs of 64 words
depth, 4x CSs, but the third one as being a part of the Baikal-T1 System
Boot Controller has got a very limited resources: no IRQ, no DMA, only a
single native chip-select and Tx/Rx FIFO with just 8 words depth
available. In order to provide a transparent initial boot code execution
the Boot SPI controller is also utilized by an vendor-specific IP-block,
which exposes an SPI flash direct mapping interface. Since both direct
mapping and SPI controller normal utilization are mutual exclusive only
one of these interfaces can be used to access an external SPI slave
device. That's why a dedicated mux is embedded into the System Boot
Controller. All of that is taken into account in the Baikal-T1-specific DW
APB SSI glue driver implemented by means of the DW SPI core module.

Co-developed-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-22-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>