--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2021 Pengutronix, Lucas Stach <kernel@pengutronix.de>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/clk.h>
+
+#include <dt-bindings/power/imx8mm-power.h>
+
+#define BLK_SFT_RSTN 0x0
+#define BLK_CLK_EN 0x4
+
+struct imx8m_blk_ctrl_domain;
+
+struct imx8m_blk_ctrl {
+ struct device *dev;
+ struct notifier_block power_nb;
+ struct device *bus_power_dev;
+ struct regmap *regmap;
+ struct imx8m_blk_ctrl_domain *domains;
+ struct genpd_onecell_data onecell_data;
+};
+
+struct imx8m_blk_ctrl_domain_data {
+ const char *name;
+ const char * const *clk_names;
+ int num_clks;
+ const char *gpc_name;
+ u32 rst_mask;
+ u32 clk_mask;
+};
+
+#define DOMAIN_MAX_CLKS 3
+
+struct imx8m_blk_ctrl_domain {
+ struct generic_pm_domain genpd;
+ const struct imx8m_blk_ctrl_domain_data *data;
+ struct clk_bulk_data clks[DOMAIN_MAX_CLKS];
+ struct device *power_dev;
+ struct imx8m_blk_ctrl *bc;
+};
+
+struct imx8m_blk_ctrl_data {
+ int max_reg;
+ notifier_fn_t power_notifier_fn;
+ const struct imx8m_blk_ctrl_domain_data *domains;
+ int num_domains;
+};
+
+static inline struct imx8m_blk_ctrl_domain *
+to_imx8m_blk_ctrl_domain(struct generic_pm_domain *genpd)
+{
+ return container_of(genpd, struct imx8m_blk_ctrl_domain, genpd);
+}
+
+static int imx8m_blk_ctrl_power_on(struct generic_pm_domain *genpd)
+{
+ struct imx8m_blk_ctrl_domain *domain = to_imx8m_blk_ctrl_domain(genpd);
+ const struct imx8m_blk_ctrl_domain_data *data = domain->data;
+ struct imx8m_blk_ctrl *bc = domain->bc;
+ int ret;
+
+ /* make sure bus domain is awake */
+ ret = pm_runtime_get_sync(bc->bus_power_dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(bc->bus_power_dev);
+ dev_err(bc->dev, "failed to power up bus domain\n");
+ return ret;
+ }
+
+ /* put devices into reset */
+ regmap_clear_bits(bc->regmap, BLK_SFT_RSTN, data->rst_mask);
+
+ /* enable upstream and blk-ctrl clocks to allow reset to propagate */
+ ret = clk_bulk_prepare_enable(data->num_clks, domain->clks);
+ if (ret) {
+ dev_err(bc->dev, "failed to enable clocks\n");
+ goto bus_put;
+ }
+ regmap_set_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
+
+ /* power up upstream GPC domain */
+ ret = pm_runtime_get_sync(domain->power_dev);
+ if (ret < 0) {
+ dev_err(bc->dev, "failed to power up peripheral domain\n");
+ goto clk_disable;
+ }
+
+ /* wait for reset to propagate */
+ udelay(5);
+
+ /* release reset */
+ regmap_set_bits(bc->regmap, BLK_SFT_RSTN, data->rst_mask);
+
+ /* disable upstream clocks */
+ clk_bulk_disable_unprepare(data->num_clks, domain->clks);
+
+ return 0;
+
+clk_disable:
+ clk_bulk_disable_unprepare(data->num_clks, domain->clks);
+bus_put:
+ pm_runtime_put(bc->bus_power_dev);
+
+ return ret;
+}
+
+static int imx8m_blk_ctrl_power_off(struct generic_pm_domain *genpd)
+{
+ struct imx8m_blk_ctrl_domain *domain = to_imx8m_blk_ctrl_domain(genpd);
+ const struct imx8m_blk_ctrl_domain_data *data = domain->data;
+ struct imx8m_blk_ctrl *bc = domain->bc;
+
+ /* put devices into reset and disable clocks */
+ regmap_clear_bits(bc->regmap, BLK_SFT_RSTN, data->rst_mask);
+ regmap_clear_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
+
+ /* power down upstream GPC domain */
+ pm_runtime_put(domain->power_dev);
+
+ /* allow bus domain to suspend */
+ pm_runtime_put(bc->bus_power_dev);
+
+ return 0;
+}
+
+static struct generic_pm_domain *
+imx8m_blk_ctrl_xlate(struct of_phandle_args *args, void *data)
+{
+ struct genpd_onecell_data *onecell_data = data;
+ unsigned int index = args->args[0];
+
+ if (args->args_count != 1 ||
+ index > onecell_data->num_domains)
+ return ERR_PTR(-EINVAL);
+
+ return onecell_data->domains[index];
+}
+
+static struct lock_class_key blk_ctrl_genpd_lock_class;
+
+static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
+{
+ const struct imx8m_blk_ctrl_data *bc_data;
+ struct device *dev = &pdev->dev;
+ struct imx8m_blk_ctrl *bc;
+ void __iomem *base;
+ int i, ret;
+
+ struct regmap_config regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ };
+
+ bc = devm_kzalloc(dev, sizeof(*bc), GFP_KERNEL);
+ if (!bc)
+ return -ENOMEM;
+
+ bc->dev = dev;
+
+ bc_data = of_device_get_match_data(dev);
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ regmap_config.max_register = bc_data->max_reg;
+ bc->regmap = devm_regmap_init_mmio(dev, base, ®map_config);
+ if (IS_ERR(bc->regmap))
+ return dev_err_probe(dev, PTR_ERR(bc->regmap),
+ "failed to init regmap\n");
+
+ bc->domains = devm_kcalloc(dev, bc_data->num_domains,
+ sizeof(struct imx8m_blk_ctrl_domain),
+ GFP_KERNEL);
+ if (!bc->domains)
+ return -ENOMEM;
+
+ bc->onecell_data.num_domains = bc_data->num_domains;
+ bc->onecell_data.xlate = imx8m_blk_ctrl_xlate;
+ bc->onecell_data.domains =
+ devm_kcalloc(dev, bc_data->num_domains,
+ sizeof(struct generic_pm_domain *), GFP_KERNEL);
+ if (!bc->onecell_data.domains)
+ return -ENOMEM;
+
+ bc->bus_power_dev = genpd_dev_pm_attach_by_name(dev, "bus");
+ if (IS_ERR(bc->bus_power_dev))
+ return dev_err_probe(dev, PTR_ERR(bc->bus_power_dev),
+ "failed to attach power domain\n");
+
+ for (i = 0; i < bc_data->num_domains; i++) {
+ const struct imx8m_blk_ctrl_domain_data *data = &bc_data->domains[i];
+ struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
+ int j;
+
+ domain->data = data;
+
+ for (j = 0; j < data->num_clks; j++)
+ domain->clks[j].id = data->clk_names[j];
+
+ ret = devm_clk_bulk_get(dev, data->num_clks, domain->clks);
+ if (ret) {
+ dev_err_probe(dev, ret, "failed to get clock\n");
+ goto cleanup_pds;
+ }
+
+ domain->power_dev =
+ dev_pm_domain_attach_by_name(dev, data->gpc_name);
+ if (IS_ERR(domain->power_dev)) {
+ dev_err_probe(dev, PTR_ERR(domain->power_dev),
+ "failed to attach power domain\n");
+ ret = PTR_ERR(domain->power_dev);
+ goto cleanup_pds;
+ }
+
+ domain->genpd.name = data->name;
+ domain->genpd.power_on = imx8m_blk_ctrl_power_on;
+ domain->genpd.power_off = imx8m_blk_ctrl_power_off;
+ domain->bc = bc;
+
+ ret = pm_genpd_init(&domain->genpd, NULL, true);
+ if (ret) {
+ dev_err_probe(dev, ret, "failed to init power domain\n");
+ dev_pm_domain_detach(domain->power_dev, true);
+ goto cleanup_pds;
+ }
+
+ /*
+ * We use runtime PM to trigger power on/off of the upstream GPC
+ * domain, as a strict hierarchical parent/child power domain
+ * setup doesn't allow us to meet the sequencing requirements.
+ * This means we have nested locking of genpd locks, without the
+ * nesting being visible at the genpd level, so we need a
+ * separate lock class to make lockdep aware of the fact that
+ * this are separate domain locks that can be nested without a
+ * self-deadlock.
+ */
+ lockdep_set_class(&domain->genpd.mlock,
+ &blk_ctrl_genpd_lock_class);
+
+ bc->onecell_data.domains[i] = &domain->genpd;
+ }
+
+ ret = of_genpd_add_provider_onecell(dev->of_node, &bc->onecell_data);
+ if (ret) {
+ dev_err_probe(dev, ret, "failed to add power domain provider\n");
+ goto cleanup_pds;
+ }
+
+ bc->power_nb.notifier_call = bc_data->power_notifier_fn;
+ ret = dev_pm_genpd_add_notifier(bc->bus_power_dev, &bc->power_nb);
+ if (ret) {
+ dev_err_probe(dev, ret, "failed to add power notifier\n");
+ goto cleanup_provider;
+ }
+
+ dev_set_drvdata(dev, bc);
+
+ return 0;
+
+cleanup_provider:
+ of_genpd_del_provider(dev->of_node);
+cleanup_pds:
+ for (i--; i >= 0; i--) {
+ pm_genpd_remove(&bc->domains[i].genpd);
+ dev_pm_domain_detach(bc->domains[i].power_dev, true);
+ }
+
+ dev_pm_domain_detach(bc->bus_power_dev, true);
+
+ return ret;
+}
+
+static int imx8m_blk_ctrl_remove(struct platform_device *pdev)
+{
+ struct imx8m_blk_ctrl *bc = dev_get_drvdata(&pdev->dev);
+ int i;
+
+ of_genpd_del_provider(pdev->dev.of_node);
+
+ for (i = 0; bc->onecell_data.num_domains; i++) {
+ struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
+
+ pm_genpd_remove(&domain->genpd);
+ dev_pm_domain_detach(domain->power_dev, true);
+ }
+
+ dev_pm_genpd_remove_notifier(bc->bus_power_dev);
+
+ dev_pm_domain_detach(bc->bus_power_dev, true);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int imx8m_blk_ctrl_suspend(struct device *dev)
+{
+ struct imx8m_blk_ctrl *bc = dev_get_drvdata(dev);
+ int ret, i;
+
+ /*
+ * This may look strange, but is done so the generic PM_SLEEP code
+ * can power down our domains and more importantly power them up again
+ * after resume, without tripping over our usage of runtime PM to
+ * control the upstream GPC domains. Things happen in the right order
+ * in the system suspend/resume paths due to the device parent/child
+ * hierarchy.
+ */
+ ret = pm_runtime_get_sync(bc->bus_power_dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(bc->bus_power_dev);
+ return ret;
+ }
+
+ for (i = 0; i < bc->onecell_data.num_domains; i++) {
+ struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
+
+ ret = pm_runtime_get_sync(domain->power_dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(domain->power_dev);
+ goto out_fail;
+ }
+ }
+
+ return 0;
+
+out_fail:
+ for (i--; i >= 0; i--)
+ pm_runtime_put(bc->domains[i].power_dev);
+
+ pm_runtime_put(bc->bus_power_dev);
+
+ return ret;
+}
+
+static int imx8m_blk_ctrl_resume(struct device *dev)
+{
+ struct imx8m_blk_ctrl *bc = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < bc->onecell_data.num_domains; i++)
+ pm_runtime_put(bc->domains[i].power_dev);
+
+ pm_runtime_put(bc->bus_power_dev);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops imx8m_blk_ctrl_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(imx8m_blk_ctrl_suspend, imx8m_blk_ctrl_resume)
+};
+
+static int imx8mm_vpu_power_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct imx8m_blk_ctrl *bc = container_of(nb, struct imx8m_blk_ctrl,
+ power_nb);
+
+ if (action != GENPD_NOTIFY_ON && action != GENPD_NOTIFY_PRE_OFF)
+ return NOTIFY_OK;
+
+ /*
+ * The ADB in the VPUMIX domain has no separate reset and clock
+ * enable bits, but is ungated together with the VPU clocks. To
+ * allow the handshake with the GPC to progress we put the VPUs
+ * in reset and ungate the clocks.
+ */
+ regmap_clear_bits(bc->regmap, BLK_SFT_RSTN, BIT(0) | BIT(1) | BIT(2));
+ regmap_set_bits(bc->regmap, BLK_CLK_EN, BIT(0) | BIT(1) | BIT(2));
+
+ if (action == GENPD_NOTIFY_ON) {
+ /*
+ * On power up we have no software backchannel to the GPC to
+ * wait for the ADB handshake to happen, so we just delay for a
+ * bit. On power down the GPC driver waits for the handshake.
+ */
+ udelay(5);
+
+ /* set "fuse" bits to enable the VPUs */
+ regmap_set_bits(bc->regmap, 0x8, 0xffffffff);
+ regmap_set_bits(bc->regmap, 0xc, 0xffffffff);
+ regmap_set_bits(bc->regmap, 0x10, 0xffffffff);
+ regmap_set_bits(bc->regmap, 0x14, 0xffffffff);
+ }
+
+ return NOTIFY_OK;
+}
+
+static const struct imx8m_blk_ctrl_domain_data imx8mm_vpu_blk_ctl_domain_data[] = {
+ [IMX8MM_VPUBLK_PD_G1] = {
+ .name = "vpublk-g1",
+ .clk_names = (const char *[]){ "g1", },
+ .num_clks = 1,
+ .gpc_name = "g1",
+ .rst_mask = BIT(1),
+ .clk_mask = BIT(1),
+ },
+ [IMX8MM_VPUBLK_PD_G2] = {
+ .name = "vpublk-g2",
+ .clk_names = (const char *[]){ "g2", },
+ .num_clks = 1,
+ .gpc_name = "g2",
+ .rst_mask = BIT(0),
+ .clk_mask = BIT(0),
+ },
+ [IMX8MM_VPUBLK_PD_H1] = {
+ .name = "vpublk-h1",
+ .clk_names = (const char *[]){ "h1", },
+ .num_clks = 1,
+ .gpc_name = "h1",
+ .rst_mask = BIT(2),
+ .clk_mask = BIT(2),
+ },
+};
+
+static const struct imx8m_blk_ctrl_data imx8mm_vpu_blk_ctl_dev_data = {
+ .max_reg = 0x18,
+ .power_notifier_fn = imx8mm_vpu_power_notifier,
+ .domains = imx8mm_vpu_blk_ctl_domain_data,
+ .num_domains = ARRAY_SIZE(imx8mm_vpu_blk_ctl_domain_data),
+};
+
+static const struct of_device_id imx8m_blk_ctrl_of_match[] = {
+ {
+ .compatible = "fsl,imx8mm-vpu-blk-ctrl",
+ .data = &imx8mm_vpu_blk_ctl_dev_data
+ }, {
+ /* Sentinel */
+ }
+};
+MODULE_DEVICE_TABLE(of, imx8m_blk_ctrl_of_match);
+
+static struct platform_driver imx8m_blk_ctrl_driver = {
+ .probe = imx8m_blk_ctrl_probe,
+ .remove = imx8m_blk_ctrl_remove,
+ .driver = {
+ .name = "imx8m-blk-ctrl",
+ .pm = &imx8m_blk_ctrl_pm_ops,
+ .of_match_table = imx8m_blk_ctrl_of_match,
+ },
+};
+module_platform_driver(imx8m_blk_ctrl_driver);
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