diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/bus/qcom-ssc-block-bus.c | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/drivers/bus/qcom-ssc-block-bus.c b/drivers/bus/qcom-ssc-block-bus.c new file mode 100644 index 000000000..eedeb29a5 --- /dev/null +++ b/drivers/bus/qcom-ssc-block-bus.c @@ -0,0 +1,389 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) 2021, Michael Srba + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pm_clock.h> +#include <linux/pm_domain.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <linux/reset.h> + +/* AXI Halt Register Offsets */ +#define AXI_HALTREQ_REG 0x0 +#define AXI_HALTACK_REG 0x4 +#define AXI_IDLE_REG 0x8 + +#define SSCAON_CONFIG0_CLAMP_EN_OVRD BIT(4) +#define SSCAON_CONFIG0_CLAMP_EN_OVRD_VAL BIT(5) + +static const char *const qcom_ssc_block_pd_names[] = { + "ssc_cx", + "ssc_mx" +}; + +struct qcom_ssc_block_bus_data { + const char *const *pd_names; + struct device *pds[ARRAY_SIZE(qcom_ssc_block_pd_names)]; + char __iomem *reg_mpm_sscaon_config0; + char __iomem *reg_mpm_sscaon_config1; + struct regmap *halt_map; + struct clk *xo_clk; + struct clk *aggre2_clk; + struct clk *gcc_im_sleep_clk; + struct clk *aggre2_north_clk; + struct clk *ssc_xo_clk; + struct clk *ssc_ahbs_clk; + struct reset_control *ssc_bcr; + struct reset_control *ssc_reset; + u32 ssc_axi_halt; + int num_pds; +}; + +static void reg32_set_bits(char __iomem *reg, u32 value) +{ + u32 tmp = ioread32(reg); + + iowrite32(tmp | value, reg); +} + +static void reg32_clear_bits(char __iomem *reg, u32 value) +{ + u32 tmp = ioread32(reg); + + iowrite32(tmp & (~value), reg); +} + +static int qcom_ssc_block_bus_init(struct device *dev) +{ + int ret; + + struct qcom_ssc_block_bus_data *data = dev_get_drvdata(dev); + + ret = clk_prepare_enable(data->xo_clk); + if (ret) { + dev_err(dev, "error enabling xo_clk: %d\n", ret); + goto err_xo_clk; + } + + ret = clk_prepare_enable(data->aggre2_clk); + if (ret) { + dev_err(dev, "error enabling aggre2_clk: %d\n", ret); + goto err_aggre2_clk; + } + + ret = clk_prepare_enable(data->gcc_im_sleep_clk); + if (ret) { + dev_err(dev, "error enabling gcc_im_sleep_clk: %d\n", ret); + goto err_gcc_im_sleep_clk; + } + + /* + * We need to intervene here because the HW logic driving these signals cannot handle + * initialization after power collapse by itself. + */ + reg32_clear_bits(data->reg_mpm_sscaon_config0, + SSCAON_CONFIG0_CLAMP_EN_OVRD | SSCAON_CONFIG0_CLAMP_EN_OVRD_VAL); + /* override few_ack/rest_ack */ + reg32_clear_bits(data->reg_mpm_sscaon_config1, BIT(31)); + + ret = clk_prepare_enable(data->aggre2_north_clk); + if (ret) { + dev_err(dev, "error enabling aggre2_north_clk: %d\n", ret); + goto err_aggre2_north_clk; + } + + ret = reset_control_deassert(data->ssc_reset); + if (ret) { + dev_err(dev, "error deasserting ssc_reset: %d\n", ret); + goto err_ssc_reset; + } + + ret = reset_control_deassert(data->ssc_bcr); + if (ret) { + dev_err(dev, "error deasserting ssc_bcr: %d\n", ret); + goto err_ssc_bcr; + } + + regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 0); + + ret = clk_prepare_enable(data->ssc_xo_clk); + if (ret) { + dev_err(dev, "error deasserting ssc_xo_clk: %d\n", ret); + goto err_ssc_xo_clk; + } + + ret = clk_prepare_enable(data->ssc_ahbs_clk); + if (ret) { + dev_err(dev, "error deasserting ssc_ahbs_clk: %d\n", ret); + goto err_ssc_ahbs_clk; + } + + return 0; + +err_ssc_ahbs_clk: + clk_disable(data->ssc_xo_clk); + +err_ssc_xo_clk: + regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 1); + + reset_control_assert(data->ssc_bcr); + +err_ssc_bcr: + reset_control_assert(data->ssc_reset); + +err_ssc_reset: + clk_disable(data->aggre2_north_clk); + +err_aggre2_north_clk: + reg32_set_bits(data->reg_mpm_sscaon_config0, BIT(4) | BIT(5)); + reg32_set_bits(data->reg_mpm_sscaon_config1, BIT(31)); + + clk_disable(data->gcc_im_sleep_clk); + +err_gcc_im_sleep_clk: + clk_disable(data->aggre2_clk); + +err_aggre2_clk: + clk_disable(data->xo_clk); + +err_xo_clk: + return ret; +} + +static void qcom_ssc_block_bus_deinit(struct device *dev) +{ + int ret; + + struct qcom_ssc_block_bus_data *data = dev_get_drvdata(dev); + + clk_disable(data->ssc_xo_clk); + clk_disable(data->ssc_ahbs_clk); + + ret = reset_control_assert(data->ssc_bcr); + if (ret) + dev_err(dev, "error asserting ssc_bcr: %d\n", ret); + + regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 1); + + reg32_set_bits(data->reg_mpm_sscaon_config1, BIT(31)); + reg32_set_bits(data->reg_mpm_sscaon_config0, BIT(4) | BIT(5)); + + ret = reset_control_assert(data->ssc_reset); + if (ret) + dev_err(dev, "error asserting ssc_reset: %d\n", ret); + + clk_disable(data->gcc_im_sleep_clk); + + clk_disable(data->aggre2_north_clk); + + clk_disable(data->aggre2_clk); + clk_disable(data->xo_clk); +} + +static int qcom_ssc_block_bus_pds_attach(struct device *dev, struct device **pds, + const char *const *pd_names, size_t num_pds) +{ + int ret; + int i; + + for (i = 0; i < num_pds; i++) { + pds[i] = dev_pm_domain_attach_by_name(dev, pd_names[i]); + if (IS_ERR_OR_NULL(pds[i])) { + ret = PTR_ERR(pds[i]) ? : -ENODATA; + goto unroll_attach; + } + } + + return num_pds; + +unroll_attach: + for (i--; i >= 0; i--) + dev_pm_domain_detach(pds[i], false); + + return ret; +}; + +static void qcom_ssc_block_bus_pds_detach(struct device *dev, struct device **pds, size_t num_pds) +{ + int i; + + for (i = 0; i < num_pds; i++) + dev_pm_domain_detach(pds[i], false); +} + +static int qcom_ssc_block_bus_pds_enable(struct device **pds, size_t num_pds) +{ + int ret; + int i; + + for (i = 0; i < num_pds; i++) { + dev_pm_genpd_set_performance_state(pds[i], INT_MAX); + ret = pm_runtime_get_sync(pds[i]); + if (ret < 0) + goto unroll_pd_votes; + } + + return 0; + +unroll_pd_votes: + for (i--; i >= 0; i--) { + dev_pm_genpd_set_performance_state(pds[i], 0); + pm_runtime_put(pds[i]); + } + + return ret; +}; + +static void qcom_ssc_block_bus_pds_disable(struct device **pds, size_t num_pds) +{ + int i; + + for (i = 0; i < num_pds; i++) { + dev_pm_genpd_set_performance_state(pds[i], 0); + pm_runtime_put(pds[i]); + } +} + +static int qcom_ssc_block_bus_probe(struct platform_device *pdev) +{ + struct qcom_ssc_block_bus_data *data; + struct device_node *np = pdev->dev.of_node; + struct of_phandle_args halt_args; + struct resource *res; + int ret; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + platform_set_drvdata(pdev, data); + + data->pd_names = qcom_ssc_block_pd_names; + data->num_pds = ARRAY_SIZE(qcom_ssc_block_pd_names); + + /* power domains */ + ret = qcom_ssc_block_bus_pds_attach(&pdev->dev, data->pds, data->pd_names, data->num_pds); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "error when attaching power domains\n"); + + ret = qcom_ssc_block_bus_pds_enable(data->pds, data->num_pds); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "error when enabling power domains\n"); + + /* low level overrides for when the HW logic doesn't "just work" */ + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpm_sscaon_config0"); + data->reg_mpm_sscaon_config0 = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(data->reg_mpm_sscaon_config0)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->reg_mpm_sscaon_config0), + "Failed to ioremap mpm_sscaon_config0\n"); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpm_sscaon_config1"); + data->reg_mpm_sscaon_config1 = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(data->reg_mpm_sscaon_config1)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->reg_mpm_sscaon_config1), + "Failed to ioremap mpm_sscaon_config1\n"); + + /* resets */ + data->ssc_bcr = devm_reset_control_get_exclusive(&pdev->dev, "ssc_bcr"); + if (IS_ERR(data->ssc_bcr)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_bcr), + "Failed to acquire reset: scc_bcr\n"); + + data->ssc_reset = devm_reset_control_get_exclusive(&pdev->dev, "ssc_reset"); + if (IS_ERR(data->ssc_reset)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_reset), + "Failed to acquire reset: ssc_reset:\n"); + + /* clocks */ + data->xo_clk = devm_clk_get(&pdev->dev, "xo"); + if (IS_ERR(data->xo_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->xo_clk), + "Failed to get clock: xo\n"); + + data->aggre2_clk = devm_clk_get(&pdev->dev, "aggre2"); + if (IS_ERR(data->aggre2_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->aggre2_clk), + "Failed to get clock: aggre2\n"); + + data->gcc_im_sleep_clk = devm_clk_get(&pdev->dev, "gcc_im_sleep"); + if (IS_ERR(data->gcc_im_sleep_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->gcc_im_sleep_clk), + "Failed to get clock: gcc_im_sleep\n"); + + data->aggre2_north_clk = devm_clk_get(&pdev->dev, "aggre2_north"); + if (IS_ERR(data->aggre2_north_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->aggre2_north_clk), + "Failed to get clock: aggre2_north\n"); + + data->ssc_xo_clk = devm_clk_get(&pdev->dev, "ssc_xo"); + if (IS_ERR(data->ssc_xo_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_xo_clk), + "Failed to get clock: ssc_xo\n"); + + data->ssc_ahbs_clk = devm_clk_get(&pdev->dev, "ssc_ahbs"); + if (IS_ERR(data->ssc_ahbs_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_ahbs_clk), + "Failed to get clock: ssc_ahbs\n"); + + ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node, "qcom,halt-regs", 1, 0, + &halt_args); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "Failed to parse qcom,halt-regs\n"); + + data->halt_map = syscon_node_to_regmap(halt_args.np); + of_node_put(halt_args.np); + if (IS_ERR(data->halt_map)) + return PTR_ERR(data->halt_map); + + data->ssc_axi_halt = halt_args.args[0]; + + qcom_ssc_block_bus_init(&pdev->dev); + + of_platform_populate(np, NULL, NULL, &pdev->dev); + + return 0; +} + +static int qcom_ssc_block_bus_remove(struct platform_device *pdev) +{ + struct qcom_ssc_block_bus_data *data = platform_get_drvdata(pdev); + + qcom_ssc_block_bus_deinit(&pdev->dev); + + iounmap(data->reg_mpm_sscaon_config0); + iounmap(data->reg_mpm_sscaon_config1); + + qcom_ssc_block_bus_pds_disable(data->pds, data->num_pds); + qcom_ssc_block_bus_pds_detach(&pdev->dev, data->pds, data->num_pds); + pm_runtime_disable(&pdev->dev); + pm_clk_destroy(&pdev->dev); + + return 0; +} + +static const struct of_device_id qcom_ssc_block_bus_of_match[] = { + { .compatible = "qcom,ssc-block-bus", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, qcom_ssc_block_bus_of_match); + +static struct platform_driver qcom_ssc_block_bus_driver = { + .probe = qcom_ssc_block_bus_probe, + .remove = qcom_ssc_block_bus_remove, + .driver = { + .name = "qcom-ssc-block-bus", + .of_match_table = qcom_ssc_block_bus_of_match, + }, +}; + +module_platform_driver(qcom_ssc_block_bus_driver); + +MODULE_DESCRIPTION("A driver for handling the init sequence needed for accessing the SSC block on (some) qcom SoCs over AHB"); +MODULE_AUTHOR("Michael Srba <Michael.Srba@seznam.cz>"); +MODULE_LICENSE("GPL v2"); |