clocksource/drivers/imx-tpm: Move tpm_read_sched_clock() under CONFIG_ARM

When building this driver for an architecture other than ARCH=arm:

drivers/clocksource/timer-imx-tpm.c:78:20: error: unused function 'tpm_read_sched_clock' [-Werror,-Wunused-function]
static u64 notrace tpm_read_sched_clock(void)
^
1 error generated.

Move the function definition under the existing CONFIG_ARM section so
there is no more warning.

Fixes: 10720e120e2b ("clocksource/drivers/imx-tpm: Exclude sched clock for ARM64")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20220303184212.2356245-1-nathan@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Exclude sched clock for ARM64

For ARM64 platform such as i.MX8ULP which has ARMv8 generic timer as sched
clock, which is much faster compared with tpm sched clock. Reading the
tpm count register in i.MX8ULP requires about 290ns, this is slow and
introduce scheduler latency. So exclude tpm sched clock for ARM64
platform.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20220105124304.3567629-1-peng.fan@oss.nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Update name of clkevt

The tpm driver is not only for i.MX7ULP now, i.MX8ULP also use it. It
maybe also used by other i.MX variants, so update name to reflect it.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20211214120737.1611955-6-peng.fan@oss.nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Add CLOCK_EVT_FEAT_DYNIRQ

Add CLOCK_EVT_FEAT_DYNIRQ to allow the IRQ could be runtime set affinity
to the cores that needs wake up, otherwise saying core0 has to send
IPI to wakeup core1. With CLOCK_EVT_FEAT_DYNIRQ set, when broadcast
timer could wake up the cores, IPI is not needed.

Acked-by: Jacky Bai <ping.bai@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20211214120737.1611955-5-peng.fan@oss.nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Mark two variable with __ro_after_init

counter_width and timer_base will not be updated after init, so mark
as __ro_after_init.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20211214120737.1611955-4-peng.fan@oss.nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Drop IRQF_IRQPOLL

Per the Documentation,
IRQF_IRQPOLL is used for polling (only the interrupt that is registered
first in a shared interrupt is considered for performance reasons)
The TPM timer is not sharing interrupt with others, and pass irqpoll
not make sense for i.MX platform.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20211214120737.1611955-3-peng.fan@oss.nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Add support for ARM64

Allows building and compile-testing the i.MX TPM driver also
for ARM64. The delay_timer is only supported on ARMv7.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1585715222-24489-1-git-send-email-Anson.Huang@nxp.com

clocksource/drivers/imx-tpm: Remove unused includes

There is nothing in use from of_address.h/of_irq.h, remove them.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1584412549-18354-1-git-send-email-Anson.Huang@nxp.com

clocksource/drivers/timer-imx-tpm: Specify clock name for timer-of

i.MX TPM needs "ipg" clock for register access and "per" clock for
timer function, the driver gets "ipg" clock by searching the clock
name, but timer-of initialization will get first clock in device
tree TPM node since no clock name specified in of_clk, that means
the "per" clock MUST be the first clock entry in device tree TPM
node, this patch specifies clock name for of_clk to avoid this
restriction, it makes TPM driver work properly with different sequence
of clock entries in device tree TPM node.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/timer-imx-tpm: Convert the driver to timer-of

Convert the driver to use the timer_of helpers. This allows to handle
timer base, clock and irq using common timer_of driver and it
simplifies the code.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/imx-tpm: Correct -ETIME return condition check

The additional brakects added to tpm_set_next_event's return value
computation causes (int) forced type conversion NOT taking effect, and the
incorrect value return will cause various system timer issue, like RCU
stall etc..

Remove the additional brackets to make sure tpm_set_next_event always
returns correct value.

Fixes: 059ab7b82eec ("clocksource/drivers/imx-tpm: Add imx tpm timer support")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dong Aisheng <Aisheng.dong@nxp.com>
Cc: stable@vger.kernel.org
Cc: daniel.lezcano@linaro.org
Cc: Linux-imx@nxp.com
Link: https://lkml.kernel.org/r/1524117883-2484-1-git-send-email-Anson.Huang@nxp.com

clocksource/drivers/imx-tpm: Add different counter width support

Different TPM modules have different width counters which is 16-bit or 32-bit,
the counter width can be read from TPM_PARAM register bit[23:16], this patch
adds dynamic check for counter width to support both 16-bit and 32-bit TPM
modules.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Correct some registers operation flow

According to i.MX7ULP reference manual, TPM_SC_CPWMS can ONLY be written when
counter is disabled, TPM_SC_TOF is write-1-clear, TPM_C0SC_CHF is also
write-1-clear, correct these registers initialization flow;

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Fix typo of clock name

The clock name should be ipg instead of igp.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/imx-tpm: Add imx tpm timer support

IMX Timer/PWM Module (TPM) supports both timer and pwm function while
this patch only adds the timer support. PWM would be added later.

The TPM counter, compare and capture registers are clocked by an
asynchronous clock that can remain enabled in low power modes.

NOTE: We observed in a very small probability, the bus fabric
contention between GPU and A7 may results a few cycles delay
of writing CNT registers which may cause the min_delta event got
missed, so we need add a ETIME check here in case it happened.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Anson Huang <Anson.Huang@nxp.com>
Cc: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>