Messages in this thread Patch in this message | | | From | Konrad Dybcio <> | Date | Wed, 23 Aug 2023 13:15:32 +0200 | Subject | [PATCH v5 2/2] irqchip: irq-qcom-mpm: Support passing a slice of SRAM as reg space |
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The MPM hardware is accessible to us from the ARM CPUs through a shared memory region (RPM MSG RAM) that's 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 basically requires us 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 some kind of a property.
Go with the third option and add a way to map a region passed through the "qcom,rpm-msg-ram" property as our register space.
The current way of using 'reg' is preserved for ABI reasons.
Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org> --- drivers/irqchip/irq-qcom-mpm.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/irqchip/irq-qcom-mpm.c b/drivers/irqchip/irq-qcom-mpm.c index 7124565234a5..7115e3056aa5 100644 --- a/drivers/irqchip/irq-qcom-mpm.c +++ b/drivers/irqchip/irq-qcom-mpm.c @@ -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 +377,21 @@ static int qcom_mpm_init(struct device_node *np, struct device_node *parent) raw_spin_lock_init(&priv->lock); - priv->base = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(priv->base)) - return PTR_ERR(priv->base); + /* 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); + /* 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); -- 2.42.0
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