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- // SPDX-License-Identifier: GPL-2.0
- /*
- * This file is part the core part STM32 DFSDM driver
- *
- * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
- * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics.
- */
- #include <linux/clk.h>
- #include <linux/iio/iio.h>
- #include <linux/iio/sysfs.h>
- #include <linux/interrupt.h>
- #include <linux/module.h>
- #include <linux/of_device.h>
- #include <linux/pinctrl/consumer.h>
- #include <linux/pm_runtime.h>
- #include <linux/regmap.h>
- #include <linux/slab.h>
- #include "stm32-dfsdm.h"
- struct stm32_dfsdm_dev_data {
- unsigned int num_filters;
- unsigned int num_channels;
- const struct regmap_config *regmap_cfg;
- };
- #define STM32H7_DFSDM_NUM_FILTERS 4
- #define STM32H7_DFSDM_NUM_CHANNELS 8
- #define STM32MP1_DFSDM_NUM_FILTERS 6
- #define STM32MP1_DFSDM_NUM_CHANNELS 8
- static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
- {
- if (reg < DFSDM_FILTER_BASE_ADR)
- return false;
- /*
- * Mask is done on register to avoid to list registers of all
- * filter instances.
- */
- switch (reg & DFSDM_FILTER_REG_MASK) {
- case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK:
- case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK:
- case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK:
- case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK:
- return true;
- }
- return false;
- }
- static const struct regmap_config stm32h7_dfsdm_regmap_cfg = {
- .reg_bits = 32,
- .val_bits = 32,
- .reg_stride = sizeof(u32),
- .max_register = 0x2B8,
- .volatile_reg = stm32_dfsdm_volatile_reg,
- .fast_io = true,
- };
- static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = {
- .num_filters = STM32H7_DFSDM_NUM_FILTERS,
- .num_channels = STM32H7_DFSDM_NUM_CHANNELS,
- .regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
- };
- static const struct regmap_config stm32mp1_dfsdm_regmap_cfg = {
- .reg_bits = 32,
- .val_bits = 32,
- .reg_stride = sizeof(u32),
- .max_register = 0x7fc,
- .volatile_reg = stm32_dfsdm_volatile_reg,
- .fast_io = true,
- };
- static const struct stm32_dfsdm_dev_data stm32mp1_dfsdm_data = {
- .num_filters = STM32MP1_DFSDM_NUM_FILTERS,
- .num_channels = STM32MP1_DFSDM_NUM_CHANNELS,
- .regmap_cfg = &stm32mp1_dfsdm_regmap_cfg,
- };
- struct dfsdm_priv {
- struct platform_device *pdev; /* platform device */
- struct stm32_dfsdm dfsdm; /* common data exported for all instances */
- unsigned int spi_clk_out_div; /* SPI clkout divider value */
- atomic_t n_active_ch; /* number of current active channels */
- struct clk *clk; /* DFSDM clock */
- struct clk *aclk; /* audio clock */
- };
- static inline struct dfsdm_priv *to_stm32_dfsdm_priv(struct stm32_dfsdm *dfsdm)
- {
- return container_of(dfsdm, struct dfsdm_priv, dfsdm);
- }
- static int stm32_dfsdm_clk_prepare_enable(struct stm32_dfsdm *dfsdm)
- {
- struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
- int ret;
- ret = clk_prepare_enable(priv->clk);
- if (ret || !priv->aclk)
- return ret;
- ret = clk_prepare_enable(priv->aclk);
- if (ret)
- clk_disable_unprepare(priv->clk);
- return ret;
- }
- static void stm32_dfsdm_clk_disable_unprepare(struct stm32_dfsdm *dfsdm)
- {
- struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
- if (priv->aclk)
- clk_disable_unprepare(priv->aclk);
- clk_disable_unprepare(priv->clk);
- }
- /**
- * stm32_dfsdm_start_dfsdm - start global dfsdm interface.
- *
- * Enable interface if n_active_ch is not null.
- * @dfsdm: Handle used to retrieve dfsdm context.
- */
- int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
- {
- struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
- struct device *dev = &priv->pdev->dev;
- unsigned int clk_div = priv->spi_clk_out_div, clk_src;
- int ret;
- if (atomic_inc_return(&priv->n_active_ch) == 1) {
- ret = pm_runtime_get_sync(dev);
- if (ret < 0) {
- pm_runtime_put_noidle(dev);
- goto error_ret;
- }
- /* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */
- clk_src = priv->aclk ? 1 : 0;
- ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
- DFSDM_CHCFGR1_CKOUTSRC_MASK,
- DFSDM_CHCFGR1_CKOUTSRC(clk_src));
- if (ret < 0)
- goto pm_put;
- /* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */
- ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
- DFSDM_CHCFGR1_CKOUTDIV_MASK,
- DFSDM_CHCFGR1_CKOUTDIV(clk_div));
- if (ret < 0)
- goto pm_put;
- /* Global enable of DFSDM interface */
- ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
- DFSDM_CHCFGR1_DFSDMEN_MASK,
- DFSDM_CHCFGR1_DFSDMEN(1));
- if (ret < 0)
- goto pm_put;
- }
- dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
- atomic_read(&priv->n_active_ch));
- return 0;
- pm_put:
- pm_runtime_put_sync(dev);
- error_ret:
- atomic_dec(&priv->n_active_ch);
- return ret;
- }
- EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);
- /**
- * stm32_dfsdm_stop_dfsdm - stop global DFSDM interface.
- *
- * Disable interface if n_active_ch is null
- * @dfsdm: Handle used to retrieve dfsdm context.
- */
- int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
- {
- struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
- int ret;
- if (atomic_dec_and_test(&priv->n_active_ch)) {
- /* Global disable of DFSDM interface */
- ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
- DFSDM_CHCFGR1_DFSDMEN_MASK,
- DFSDM_CHCFGR1_DFSDMEN(0));
- if (ret < 0)
- return ret;
- /* Stop SPI CLKOUT */
- ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
- DFSDM_CHCFGR1_CKOUTDIV_MASK,
- DFSDM_CHCFGR1_CKOUTDIV(0));
- if (ret < 0)
- return ret;
- pm_runtime_put_sync(&priv->pdev->dev);
- }
- dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
- atomic_read(&priv->n_active_ch));
- return 0;
- }
- EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm);
- static int stm32_dfsdm_parse_of(struct platform_device *pdev,
- struct dfsdm_priv *priv)
- {
- struct device_node *node = pdev->dev.of_node;
- struct resource *res;
- unsigned long clk_freq, divider;
- unsigned int spi_freq, rem;
- int ret;
- if (!node)
- return -EINVAL;
- priv->dfsdm.base = devm_platform_get_and_ioremap_resource(pdev, 0,
- &res);
- if (IS_ERR(priv->dfsdm.base))
- return PTR_ERR(priv->dfsdm.base);
- priv->dfsdm.phys_base = res->start;
- /*
- * "dfsdm" clock is mandatory for DFSDM peripheral clocking.
- * "dfsdm" or "audio" clocks can be used as source clock for
- * the SPI clock out signal and internal processing, depending
- * on use case.
- */
- priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
- if (IS_ERR(priv->clk))
- return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
- "Failed to get clock\n");
- priv->aclk = devm_clk_get(&pdev->dev, "audio");
- if (IS_ERR(priv->aclk))
- priv->aclk = NULL;
- if (priv->aclk)
- clk_freq = clk_get_rate(priv->aclk);
- else
- clk_freq = clk_get_rate(priv->clk);
- /* SPI clock out frequency */
- ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
- &spi_freq);
- if (ret < 0) {
- /* No SPI master mode */
- return 0;
- }
- divider = div_u64_rem(clk_freq, spi_freq, &rem);
- /* Round up divider when ckout isn't precise, not to exceed spi_freq */
- if (rem)
- divider++;
- /* programmable divider is in range of [2:256] */
- if (divider < 2 || divider > 256) {
- dev_err(&pdev->dev, "spi-max-frequency not achievable\n");
- return -EINVAL;
- }
- /* SPI clock output divider is: divider = CKOUTDIV + 1 */
- priv->spi_clk_out_div = divider - 1;
- priv->dfsdm.spi_master_freq = clk_freq / (priv->spi_clk_out_div + 1);
- if (rem) {
- dev_warn(&pdev->dev, "SPI clock not accurate\n");
- dev_warn(&pdev->dev, "%ld = %d * %d + %d\n",
- clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem);
- }
- return 0;
- };
- static const struct of_device_id stm32_dfsdm_of_match[] = {
- {
- .compatible = "st,stm32h7-dfsdm",
- .data = &stm32h7_dfsdm_data,
- },
- {
- .compatible = "st,stm32mp1-dfsdm",
- .data = &stm32mp1_dfsdm_data,
- },
- {}
- };
- MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);
- static int stm32_dfsdm_probe(struct platform_device *pdev)
- {
- struct dfsdm_priv *priv;
- const struct stm32_dfsdm_dev_data *dev_data;
- struct stm32_dfsdm *dfsdm;
- int ret;
- priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
- priv->pdev = pdev;
- dev_data = of_device_get_match_data(&pdev->dev);
- dfsdm = &priv->dfsdm;
- dfsdm->fl_list = devm_kcalloc(&pdev->dev, dev_data->num_filters,
- sizeof(*dfsdm->fl_list), GFP_KERNEL);
- if (!dfsdm->fl_list)
- return -ENOMEM;
- dfsdm->num_fls = dev_data->num_filters;
- dfsdm->ch_list = devm_kcalloc(&pdev->dev, dev_data->num_channels,
- sizeof(*dfsdm->ch_list),
- GFP_KERNEL);
- if (!dfsdm->ch_list)
- return -ENOMEM;
- dfsdm->num_chs = dev_data->num_channels;
- ret = stm32_dfsdm_parse_of(pdev, priv);
- if (ret < 0)
- return ret;
- dfsdm->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dfsdm",
- dfsdm->base,
- dev_data->regmap_cfg);
- if (IS_ERR(dfsdm->regmap)) {
- ret = PTR_ERR(dfsdm->regmap);
- dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n",
- __func__, ret);
- return ret;
- }
- platform_set_drvdata(pdev, dfsdm);
- ret = stm32_dfsdm_clk_prepare_enable(dfsdm);
- if (ret) {
- dev_err(&pdev->dev, "Failed to start clock\n");
- return ret;
- }
- pm_runtime_get_noresume(&pdev->dev);
- pm_runtime_set_active(&pdev->dev);
- pm_runtime_enable(&pdev->dev);
- ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
- if (ret)
- goto pm_put;
- pm_runtime_put(&pdev->dev);
- return 0;
- pm_put:
- pm_runtime_disable(&pdev->dev);
- pm_runtime_set_suspended(&pdev->dev);
- pm_runtime_put_noidle(&pdev->dev);
- stm32_dfsdm_clk_disable_unprepare(dfsdm);
- return ret;
- }
- static int stm32_dfsdm_core_remove(struct platform_device *pdev)
- {
- struct stm32_dfsdm *dfsdm = platform_get_drvdata(pdev);
- pm_runtime_get_sync(&pdev->dev);
- of_platform_depopulate(&pdev->dev);
- pm_runtime_disable(&pdev->dev);
- pm_runtime_set_suspended(&pdev->dev);
- pm_runtime_put_noidle(&pdev->dev);
- stm32_dfsdm_clk_disable_unprepare(dfsdm);
- return 0;
- }
- static int __maybe_unused stm32_dfsdm_core_suspend(struct device *dev)
- {
- struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
- struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
- int ret;
- ret = pm_runtime_force_suspend(dev);
- if (ret)
- return ret;
- /* Balance devm_regmap_init_mmio_clk() clk_prepare() */
- clk_unprepare(priv->clk);
- return pinctrl_pm_select_sleep_state(dev);
- }
- static int __maybe_unused stm32_dfsdm_core_resume(struct device *dev)
- {
- struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
- struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
- int ret;
- ret = pinctrl_pm_select_default_state(dev);
- if (ret)
- return ret;
- ret = clk_prepare(priv->clk);
- if (ret)
- return ret;
- return pm_runtime_force_resume(dev);
- }
- static int __maybe_unused stm32_dfsdm_core_runtime_suspend(struct device *dev)
- {
- struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
- stm32_dfsdm_clk_disable_unprepare(dfsdm);
- return 0;
- }
- static int __maybe_unused stm32_dfsdm_core_runtime_resume(struct device *dev)
- {
- struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
- return stm32_dfsdm_clk_prepare_enable(dfsdm);
- }
- static const struct dev_pm_ops stm32_dfsdm_core_pm_ops = {
- SET_SYSTEM_SLEEP_PM_OPS(stm32_dfsdm_core_suspend,
- stm32_dfsdm_core_resume)
- SET_RUNTIME_PM_OPS(stm32_dfsdm_core_runtime_suspend,
- stm32_dfsdm_core_runtime_resume,
- NULL)
- };
- static struct platform_driver stm32_dfsdm_driver = {
- .probe = stm32_dfsdm_probe,
- .remove = stm32_dfsdm_core_remove,
- .driver = {
- .name = "stm32-dfsdm",
- .of_match_table = stm32_dfsdm_of_match,
- .pm = &stm32_dfsdm_core_pm_ops,
- },
- };
- module_platform_driver(stm32_dfsdm_driver);
- MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
- MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver");
- MODULE_LICENSE("GPL v2");
|