Commit 221b110d authored by Konrad Dybcio's avatar Konrad Dybcio Committed by Thomas Gleixner
Browse files

irqchip/qcom-mpm: Support passing a slice of SRAM as reg space 



The MPM hardware is accessible from the ARM CPUs through a shared memory
region (RPM MSG RAM) which is also concurrently accessed by other kinds of
cores on the system like modem, ADSP etc.

Modeling this relation in a (somewhat) sane manner in the device tree
requires to

  - either present the MPM as a child of said memory region, which
    makes little sense, as a mapped memory carveout is not a bus.

  - define nodes which bleed their register spaces into one another

  - or passing their slice of the MSG RAM through a property

Go with the third option and add a way to map a region passed through the
"qcom,rpm-msg-ram" property as register space for the MPM interrupt
controller.

The current way of using 'reg' is preserved for backwards compatibility
reasons.

[ tglx: Massaged changelog ]

Signed-off-by: default avatarKonrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarBryan O'Donoghue <bryan.odonoghue@linaro.org>
Acked-by: default avatarShawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20230328-topic-msgram_mpm-v7-2-6ee2bfeaac2c@linaro.org
parent ca596295

drivers/irqchip/irq-qcom-mpm.c

+23 −3
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/mailbox_client.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/pm_domain.h>
@@ -322,8 +323,10 @@ static int qcom_mpm_init(struct device_node *np, struct device_node *parent) 
	struct device *dev = &pdev->dev;

	struct irq_domain *parent_domain;

	struct generic_pm_domain *genpd;

	struct device_node *msgram_np;

	struct qcom_mpm_priv *priv;

	unsigned int pin_cnt;

	struct resource res;

	int i, irq;

	int ret;
@@ -374,9 +377,26 @@ static int qcom_mpm_init(struct device_node *np, struct device_node *parent) 


	raw_spin_lock_init(&priv->lock);



	/* If we have a handle to an RPM message ram partition, use it. */

	msgram_np = of_parse_phandle(np, "qcom,rpm-msg-ram", 0);

	if (msgram_np) {

		ret = of_address_to_resource(msgram_np, 0, &res);

		if (ret) {

			of_node_put(msgram_np);

			return ret;

		}



		/* Don't use devm_ioremap_resource, as we're accessing a shared region. */

		priv->base = devm_ioremap(dev, res.start, resource_size(&res));

		of_node_put(msgram_np);

		if (IS_ERR(priv->base))

			return PTR_ERR(priv->base);

	} else {

		/* Otherwise, fall back to simple MMIO. */

		priv->base = devm_platform_ioremap_resource(pdev, 0);

		if (IS_ERR(priv->base))

			return PTR_ERR(priv->base);

	}



	for (i = 0; i < priv->reg_stride; i++) {

		qcom_mpm_write(priv, MPM_REG_ENABLE, i, 0);