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SubjectRe: [v3,2/2] clk: qcom: clk-rpmh: Add QCOM RPMh clock driver
On Sat, Apr 14, 2018 at 08:06:41AM +0530, Taniya Das wrote:
> Add the RPMh clock driver to control the RPMh managed clock resources on
> some of the Qualcomm Technologies, Inc. SoCs.
>
> Signed-off-by: David Collins <collinsd@codeaurora.org>
> Signed-off-by: Amit Nischal <anischal@codeaurora.org>
> ---
> drivers/clk/qcom/Kconfig | 9 ++
> drivers/clk/qcom/Makefile | 1 +
> drivers/clk/qcom/clk-rpmh.c | 367 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 377 insertions(+)
> create mode 100644 drivers/clk/qcom/clk-rpmh.c
>
> --
> diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
> index fbf4532..63c3372 100644
> --- a/drivers/clk/qcom/Kconfig
> +++ b/drivers/clk/qcom/Kconfig
> @@ -112,6 +112,15 @@ config IPQ_GCC_8074
> i2c, USB, SD/eMMC, etc. Select this for the root clock
> of ipq8074.
>
> +config QCOM_CLK_RPMH
> + tristate "RPMh Clock Driver"
> + depends on COMMON_CLK_QCOM && QCOM_RPMH
> + help
> + RPMh manages shared resources on some Qualcomm Technologies, Inc.
> + SoCs. It accepts requests from other hardware subsystems via RSC.
> + Say Y if you want to support the clocks exposed by RPMh on
> + platforms such as sdm845.
> +
> config MSM_GCC_8660
> tristate "MSM8660 Global Clock Controller"
> depends on COMMON_CLK_QCOM
> diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
> index 230332c..b2b5babf 100644
> --- a/drivers/clk/qcom/Makefile
> +++ b/drivers/clk/qcom/Makefile
> @@ -36,5 +36,6 @@ obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
> obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
> obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
> obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
> +obj-$(CONFIG_QCOM_CLK_RPMH) += clk-rpmh.o
> obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
> obj-$(CONFIG_SPMI_PMIC_CLKDIV) += clk-spmi-pmic-div.o
> diff --git a/drivers/clk/qcom/clk-rpmh.c b/drivers/clk/qcom/clk-rpmh.c
> new file mode 100644
> index 0000000..fa61284
> --- /dev/null
> +++ b/drivers/clk/qcom/clk-rpmh.c
> @@ -0,0 +1,367 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <soc/qcom/cmd-db.h>
> +#include <soc/qcom/rpmh.h>
> +
> +#include <dt-bindings/clock/qcom,rpmh.h>
> +
> +#define CLK_RPMH_ARC_EN_OFFSET 0
> +#define CLK_RPMH_VRM_EN_OFFSET 4
> +#define CLK_RPMH_APPS_RSC_AO_STATE_MASK (BIT(RPMH_WAKE_ONLY_STATE) | \
> + BIT(RPMH_ACTIVE_ONLY_STATE))
> +#define CLK_RPMH_APPS_RSC_STATE_MASK (BIT(RPMH_WAKE_ONLY_STATE) | \
> + BIT(RPMH_ACTIVE_ONLY_STATE) | \
> + BIT(RPMH_SLEEP_STATE))
> +struct clk_rpmh {
> + struct clk_hw hw;
> + const char *res_name;
> + u32 res_addr;
> + u32 res_en_offset;
> + u32 res_on_val;
> + u32 res_off_val;
> + u32 state;
> + u32 aggr_state;
> + u32 last_sent_aggr_state;
> + u32 valid_state_mask;
> + struct rpmh_client *rpmh_client;
> + struct device *dev;
> + struct clk_rpmh *peer;
> + unsigned long rate;
> +};
> +
> +struct rpmh_cc {
> + struct clk_onecell_data data;
> + struct clk *clks[];
> +};
> +
> +struct clk_rpmh_desc {
> + struct clk_hw **clks;
> + size_t num_clks;
> +};

Could you briefly document the struct members, especially struct clk_rpmh?

> +static DEFINE_MUTEX(rpmh_clk_lock);
> +
> +#define __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name, \
> + _res_en_offset, _res_on, _res_off, _rate) \
> + static struct clk_rpmh _platform##_##_name_active; \
> + static struct clk_rpmh _platform##_##_name = { \
> + .res_name = _res_name, \
> + .res_en_offset = _res_en_offset, \
> + .res_on_val = _res_on, \
> + .res_off_val = _res_off, \
> + .rate = _rate, \
> + .peer = &_platform##_##_name_active, \
> + .valid_state_mask = CLK_RPMH_APPS_RSC_STATE_MASK, \
> + .hw.init = &(struct clk_init_data){ \
> + .ops = &clk_rpmh_ops, \
> + .name = #_name, \
> + }, \
> + }; \
> + static struct clk_rpmh _platform##_##_name_active = { \
> + .res_name = _res_name, \
> + .res_en_offset = _res_en_offset, \
> + .res_on_val = _res_on, \
> + .res_off_val = _res_off, \
> + .rate = _rate, \
> + .peer = &_platform##_##_name, \
> + .valid_state_mask = CLK_RPMH_APPS_RSC_AO_STATE_MASK, \
> + .hw.init = &(struct clk_init_data){ \
> + .ops = &clk_rpmh_ops, \
> + .name = #_name_active, \
> + }, \
> + }
> +
> +#define DEFINE_CLK_RPMH_ARC(_platform, _name, _name_active, _res_name, \
> + _res_on, _res_off, _rate) \
> + __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name, \
> + CLK_RPMH_ARC_EN_OFFSET, _res_on, _res_off, _rate)
> +
> +#define DEFINE_CLK_RPMH_VRM(_platform, _name, _name_active, _res_name, \
> + _rate) \
> + __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name, \
> + CLK_RPMH_VRM_EN_OFFSET, true, false, _rate)
> +
> +static inline struct clk_rpmh *to_clk_rpmh(struct clk_hw *_hw)
> +{
> + return container_of(_hw, struct clk_rpmh, hw);
> +}
> +
> +static inline bool has_state_changed(struct clk_rpmh *c, u32 state)
> +{
> + return ((c->last_sent_aggr_state & BIT(state))
> + != (c->aggr_state & BIT(state)));
> +}
> +
> +static int clk_rpmh_send_aggregate_command(struct clk_rpmh *c)
> +{
> + struct tcs_cmd cmd = { 0 };
> + u32 cmd_state, on_val;
> + enum rpmh_state state = RPMH_SLEEP_STATE;
> + int ret = 0;

nit: initialization of 'ret' is not needed.

> +
> + cmd.addr = c->res_addr + c->res_en_offset;
> + cmd_state = c->aggr_state;
> + on_val = c->res_on_val;
> +
> + for (; state <= RPMH_ACTIVE_ONLY_STATE; state++) {

It would be clearer to initialize 'state' here.

> + if (has_state_changed(c, state)) {
> + cmd.data = (cmd_state & BIT(state)) ? on_val : 0;
~
Shouldn't this be c->res_off_val?

> + ret = rpmh_write_async(c->rpmh_client, state,
> + &cmd, 1);
> + if (ret) {
> + dev_err(c->dev, "set %s state of %s failed: (%d)\n",
> + (!state) ? "sleep" :
> + (state == RPMH_WAKE_ONLY_STATE) ?
> + "wake" : "active", c->res_name, ret);
> + return ret;
> + }
> + }
> + }
> +
> + c->last_sent_aggr_state = c->aggr_state;
> + c->peer->last_sent_aggr_state = c->last_sent_aggr_state;
> +
> + return 0;
> +}
> +
> +static int clk_rpmh_aggregate_state_send_command(struct clk_rpmh *c,
> + bool enable)
> +{
> + int ret;
> +
> + /* Update state and aggregate state values based on enable value. */
> + c->state = enable ? c->valid_state_mask : 0;
> + c->aggr_state = c->state | c->peer->state;
> + c->peer->aggr_state = c->aggr_state;
> +
> + ret = clk_rpmh_send_aggregate_command(c);
> + if (ret && enable) {
> + c->state = 0;
> + } else if (ret) {
> + c->state = c->valid_state_mask;
> + WARN(1, "clk: %s failed to disable\n", c->res_name);
> + }
> +
> + return ret;
> +}
> +
> +static int clk_rpmh_prepare(struct clk_hw *hw)
> +{
> + struct clk_rpmh *c = to_clk_rpmh(hw);
> + int ret = 0;
> +
> + mutex_lock(&rpmh_clk_lock);
> +
> + if (c->state)
> + goto out;
> +
> + ret = clk_rpmh_aggregate_state_send_command(c, true);

This ends up calling rpmh_write_async(), hence the operation might
still be in flight when the function returns. Is this intended?

> +out:
> + mutex_unlock(&rpmh_clk_lock);
> + return ret;
> +};
> +
> +static void clk_rpmh_unprepare(struct clk_hw *hw)
> +{
> + struct clk_rpmh *c = to_clk_rpmh(hw);
> +
> + mutex_lock(&rpmh_clk_lock);
> +
> + if (!c->state)
> + goto out;
> +
> + clk_rpmh_aggregate_state_send_command(c, false);
> +out:
> + mutex_unlock(&rpmh_clk_lock);
> + return;
> +};
> +
> +static unsigned long clk_rpmh_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + struct clk_rpmh *r = to_clk_rpmh(hw);
> +
> + /*
> + * RPMh clocks have a fixed rate. Return static rate set
> + * at init time.
> + */
> + return r->rate;
> +}
> +
> +static const struct clk_ops clk_rpmh_ops = {
> + .prepare = clk_rpmh_prepare,
> + .unprepare = clk_rpmh_unprepare,
> + .recalc_rate = clk_rpmh_recalc_rate,
> +};
> +
> +/* Resource name must match resource id present in cmd-db. */
> +DEFINE_CLK_RPMH_ARC(sdm845, bi_tcxo, bi_tcxo_ao, "xo.lvl", 0x3, 0x0, 19200000);
> +DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk2, ln_bb_clk2_ao, "lnbclka2", 19200000);
> +DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk3, ln_bb_clk3_ao, "lnbclka3", 19200000);
> +DEFINE_CLK_RPMH_VRM(sdm845, rf_clk1, rf_clk1_ao, "rfclka1", 38400000);
> +DEFINE_CLK_RPMH_VRM(sdm845, rf_clk2, rf_clk2_ao, "rfclka2", 38400000);
> +DEFINE_CLK_RPMH_VRM(sdm845, rf_clk3, rf_clk3_ao, "rfclka3", 38400000);
> +
> +static struct clk_hw *sdm845_rpmh_clocks[] = {
> + [RPMH_CXO_CLK] = &sdm845_bi_tcxo.hw,
> + [RPMH_CXO_CLK_A] = &sdm845_bi_tcxo_ao.hw,
> + [RPMH_LN_BB_CLK2] = &sdm845_ln_bb_clk2.hw,
> + [RPMH_LN_BB_CLK2_A] = &sdm845_ln_bb_clk2_ao.hw,
> + [RPMH_LN_BB_CLK3] = &sdm845_ln_bb_clk3.hw,
> + [RPMH_LN_BB_CLK3_A] = &sdm845_ln_bb_clk3_ao.hw,
> + [RPMH_RF_CLK1] = &sdm845_rf_clk1.hw,
> + [RPMH_RF_CLK1_A] = &sdm845_rf_clk1_ao.hw,
> + [RPMH_RF_CLK2] = &sdm845_rf_clk2.hw,
> + [RPMH_RF_CLK2_A] = &sdm845_rf_clk2_ao.hw,
> + [RPMH_RF_CLK3] = &sdm845_rf_clk3.hw,
> + [RPMH_RF_CLK3_A] = &sdm845_rf_clk3_ao.hw,
> +};
> +
> +static const struct clk_rpmh_desc clk_rpmh_sdm845 = {
> + .clks = sdm845_rpmh_clocks,
> + .num_clks = ARRAY_SIZE(sdm845_rpmh_clocks),
> +};
> +
> +static int clk_rpmh_probe(struct platform_device *pdev)
> +{
> + struct clk **clks;
> + struct clk *clk;
> + struct rpmh_cc *rcc;
> + struct clk_onecell_data *data;
> + struct clk_hw **hw_clks;
> + struct clk_rpmh *rpmh_clk;
> + const struct clk_rpmh_desc *desc;
> + struct rpmh_client *rpmh_client;
> + struct device *dev;
> + size_t num_clks, i;
> + int ret;
> +
> + dev = &pdev->dev;
> +
> + ret = cmd_db_ready();
> + if (ret) {
> + if (ret != -EPROBE_DEFER) {
> + dev_err(dev, "Command DB not available (%d)\n", ret);
> + goto fail;
> + }
> + return ret;
> + }
> +
> + rpmh_client = rpmh_get_client(pdev);
> + if (IS_ERR(rpmh_client)) {
> + ret = PTR_ERR(rpmh_client);
> + dev_err(dev, "Failed to request RPMh client, ret=%d\n", ret);
> + return ret;
> + }
> +
> + desc = of_device_get_match_data(&pdev->dev);
> + hw_clks = desc->clks;
> + num_clks = desc->num_clks;
> +
> + rcc = devm_kzalloc(&pdev->dev, sizeof(*rcc) + sizeof(*clks) * num_clks,
> + GFP_KERNEL);
> + if (!rcc) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + clks = rcc->clks;
> + data = &rcc->data;
> + data->clks = clks;
> + data->clk_num = num_clks;
> +
> + for (i = 0; i < num_clks; i++) {
> + rpmh_clk = to_clk_rpmh(hw_clks[i]);
> + rpmh_clk->res_addr = cmd_db_read_addr(rpmh_clk->res_name);
> + if (!rpmh_clk->res_addr) {
> + dev_err(dev, "missing RPMh resource address for %s\n",
> + rpmh_clk->res_name);
> + ret = -ENODEV;
> + goto err;
> + }
> +
> + rpmh_clk->rpmh_client = rpmh_client;
> +
> + clk = devm_clk_register(&pdev->dev, hw_clks[i]);
> + if (IS_ERR(clk)) {
> + ret = PTR_ERR(clk);
> + dev_err(dev, "failed to register %s\n",
> + hw_clks[i]->init->name);
> + goto err;
> + }
> +
> + clks[i] = clk;
> + rpmh_clk->dev = &pdev->dev;
> + }
> +
> + ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_onecell_get,
> + data);
> + if (ret) {
> + dev_err(dev, "Failed to add clock provider\n");
> + goto err;
> + }
> +
> + dev_dbg(dev, "Registered RPMh clocks\n");
> +
> + return 0;
> +err:
> + if (rpmh_client)
> + rpmh_release(rpmh_client);
> +fail:
> + dev_err(dev, "Error registering RPMh Clock driver (%d)\n", ret);
> + return ret;
> +}
> +
> +static int clk_rpmh_remove(struct platform_device *pdev)
> +{
> + const struct clk_rpmh_desc *desc =
> + of_device_get_match_data(&pdev->dev);
> + struct clk_hw **hw_clks = desc->clks;
> + struct clk_rpmh *rpmh_clk = to_clk_rpmh(hw_clks[0]);
> +
> + rpmh_release(rpmh_clk->rpmh_client);
> + of_clk_del_provider(pdev->dev.of_node);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id clk_rpmh_match_table[] = {
> + { .compatible = "qcom,sdm845-rpmh-clk", .data = &clk_rpmh_sdm845},
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, clk_rpmh_match_table);
> +
> +static struct platform_driver clk_rpmh_driver = {
> + .probe = clk_rpmh_probe,
> + .remove = clk_rpmh_remove,
> + .driver = {
> + .name = "clk-rpmh",
> + .of_match_table = clk_rpmh_match_table,
> + },
> +};
> +
> +static int __init clk_rpmh_init(void)
> +{
> + return platform_driver_register(&clk_rpmh_driver);
> +}
> +subsys_initcall(clk_rpmh_init);
> +
> +static void __exit clk_rpmh_exit(void)
> +{
> + platform_driver_unregister(&clk_rpmh_driver);
> +}
> +module_exit(clk_rpmh_exit);
> +
> +MODULE_DESCRIPTION("QCOM RPMh Clock Driver");
> +MODULE_LICENSE("GPL v2");

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