[PATCH 2/9] iommu/rockchip: Attach multiple power domains

[Tomeu Vizoso]

IOMMUs with multiple base addresses can also have multiple power
domains.

The base framework only takes care of a single power domain, as some
devices will need for these power domains to be powered on in a specific
order.

Use a helper function to stablish links in the order in which they are
in the DT.

This is needed by the IOMMU used by the NPU in the RK3588.

Signed-off-by: Tomeu Vizoso <to...@tomeuvizoso.net>
---
 drivers/iommu/rockchip-iommu.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index f5629515bd78..673b0ebb6262 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -6,6 +6,8 @@
  *                     Daniel Kurtz <djku...@chromium.org>
  */
 
+#include "linux/err.h"
+#include "linux/pm_domain.h"
 #include <linux/clk.h>
 #include <linux/compiler.h>
 #include <linux/delay.h>
@@ -115,6 +117,7 @@ struct rk_iommu {
        struct iommu_device iommu;
        struct list_head node; /* entry in rk_iommu_domain.iommus */
        struct iommu_domain *domain; /* domain to which iommu is attached */
+       struct dev_pm_domain_list *pmdomains;
 };
 
 struct rk_iommudata {
@@ -1186,6 +1189,7 @@ static int rk_iommu_probe(struct platform_device *pdev)
        struct resource *res;
        const struct rk_iommu_ops *ops;
        int num_res = pdev->num_resources;
+       int pm_domain_count;
        int err, i;
 
        iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
@@ -1271,6 +1275,35 @@ static int rk_iommu_probe(struct platform_device *pdev)
        if (!dma_dev)
                dma_dev = &pdev->dev;
 
+       pm_domain_count = of_property_count_strings(iommu->dev->of_node, 
"power-domain-names");
+       if (pm_domain_count > 0) {
+               const char **pm_domains = kvmalloc_array(pm_domain_count, 
sizeof(*pm_domains), GFP_KERNEL);
+               struct dev_pm_domain_attach_data pm_domain_data = {
+                       .pd_names = pm_domains,
+                       .num_pd_names = pm_domain_count,
+                       .pd_flags = PD_FLAG_DEV_LINK_ON,
+               };
+               int i;
+
+               if (!pm_domain_data.pd_names) {
+                       err = -ENOMEM;
+                       goto err_remove_sysfs;
+               }
+
+               for (i = 0; i < pm_domain_count; i++) {
+                       err = 
of_property_read_string_index(iommu->dev->of_node, "power-domain-names", i, 
&pm_domains[i]);
+                       if (err) {
+                               kfree(pm_domains);
+                               goto err_remove_sysfs;
+                       }
+               }
+
+               err = dev_pm_domain_attach_list(iommu->dev, &pm_domain_data, 
&iommu->pmdomains);
+               kfree(pm_domains);
+               if (err < 0)
+                       goto err_remove_sysfs;
+       }
+
        pm_runtime_enable(dev);
 
        for (i = 0; i < iommu->num_irq; i++) {
@@ -1292,6 +1325,7 @@ static int rk_iommu_probe(struct platform_device *pdev)
        return 0;
 err_pm_disable:
        pm_runtime_disable(dev);
+       dev_pm_domain_detach_list(iommu->pmdomains);
 err_remove_sysfs:
        iommu_device_sysfs_remove(&iommu->iommu);
 err_unprepare_clocks:
@@ -1310,6 +1344,8 @@ static void rk_iommu_shutdown(struct platform_device 
*pdev)
                devm_free_irq(iommu->dev, irq, iommu);
        }
 
+       dev_pm_domain_detach_list(iommu->pmdomains);
+
        pm_runtime_force_suspend(&pdev->dev);
 }
 

-- 
2.45.2