Commit Graph

3 Commits

Author SHA1 Message Date
Linus Walleij
f905293d65 clk: gemini: Fix reset regression
commit e2860e1f62 ("serial: 8250_of: Add reset support")
introduced reset support for the 8250_of driver.

However it unconditionally uses the assert/deassert pair to
deassert reset on the device at probe and assert it at
remove. This does not work with systems that have a
self-deasserting reset controller, such as Gemini, that
recently added a reset controller.

As a result, the console will not probe on the Gemini with
this message:

Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled
of_serial: probe of 42000000.serial failed with error -524

This (-ENOTSUPP) is the error code returned by the
deassert() operation on self-deasserting reset controllers.

To work around this, implement dummy .assert() and
.deassert() operations in the Gemini combined clock and
reset controller. This fixes the issue on this system.

Cc: Joel Stanley <joel@jms.id.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Fixes: e2860e1f62 ("serial: 8250_of: Add reset support")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-07-17 11:51:10 -07:00
Joel Stanley
785b62167d clk: gemini: Read status before using the value
The probe does a shift and mask of val without having read it from the hardware.

Fixes: 846423f967 ("clk: Add Gemini SoC clock controller")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-06-29 18:47:35 -07:00
Linus Walleij
846423f967 clk: Add Gemini SoC clock controller
The Cortina Systems Gemini (SL3516/CS3516) has an on-chip clock
controller that derive all clocks from a single crystal, using some
documented and some undocumented PLLs, half dividers, counters and
gates. This is a best attempt to construct a clock driver for the
clocks so at least we can gate off unused hardware and driver the
PCI bus clock.

Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[sboyd@codeaurora.org: Fix devm_ioremap_resource() return value
checking]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-06-21 10:45:54 -07:00