From: Rahul Pathak <rpathak@xxxxxxxxxxxxxxxx> The RPMI specification defines a clock service group which can be accessed via SBI MPXY extension or dedicated S-mode RPMI transport. Add mailbox client based clock driver for the RISC-V RPMI clock service group. Co-developed-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx> Signed-off-by: Rahul Pathak <rpathak@xxxxxxxxxxxxxxxx> --- drivers/clk/Kconfig | 8 + drivers/clk/Makefile | 1 + drivers/clk/clk-rpmi.c | 588 +++++++++++++++++++++ include/linux/mailbox/riscv-rpmi-message.h | 16 + 4 files changed, 613 insertions(+) create mode 100644 drivers/clk/clk-rpmi.c diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 713573b6c86c..874cea2ab21c 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -493,6 +493,14 @@ config COMMON_CLK_SP7021 Not all features of the PLL are currently supported by the driver. +config COMMON_CLK_RPMI + tristate "Clock driver based on RISC-V RPMI" + depends on MAILBOX || COMPILE_TEST + default RISCV + help + Support for clocks based on the clock service group defined by + the RISC-V platform management interface (RPMI) specification. + source "drivers/clk/actions/Kconfig" source "drivers/clk/analogbits/Kconfig" source "drivers/clk/baikal-t1/Kconfig" diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index bf4bd45adc3a..95ef59e439bf 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -107,6 +107,7 @@ obj-$(CONFIG_COMMON_CLK_VC5) += clk-versaclock5.o obj-$(CONFIG_COMMON_CLK_VC7) += clk-versaclock7.o obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o obj-$(CONFIG_COMMON_CLK_XGENE) += clk-xgene.o +obj-$(CONFIG_COMMON_CLK_RPMI) += clk-rpmi.o # please keep this section sorted lexicographically by directory path name obj-y += actions/ diff --git a/drivers/clk/clk-rpmi.c b/drivers/clk/clk-rpmi.c new file mode 100644 index 000000000000..ed8e32527d3d --- /dev/null +++ b/drivers/clk/clk-rpmi.c @@ -0,0 +1,588 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RISC-V MPXY Based Clock Driver + * + * Copyright (C) 2024 Ventana Micro Systems Ltd. + */ + +#include <linux/io.h> +#include <linux/mm.h> +#include <linux/of.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/mailbox/riscv-rpmi-message.h> +#include <linux/mailbox_client.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/clk-provider.h> + +#define RPMI_CLK_MAX_NUM_RATES 16 +#define RPMI_CLK_NAME_LEN 16 + +#define GET_RATE_LO_U32(rate_u64) ((u32)rate_u64) +#define GET_RATE_HI_U32(rate_u64) ((u32)((u64)(rate_u64) >> 32)) +#define GET_RATE_U64(hi_u32, lo_u32) ((u64)(hi_u32) << 32 | (lo_u32)) + +enum rpmi_clk_config { + RPMI_CLK_DISABLE = 0, + RPMI_CLK_ENABLE = 1, +}; + +enum rpmi_clk_type { + RPMI_CLK_DISCRETE = 0, + RPMI_CLK_LINEAR = 1, + RPMI_CLK_TYPE_MAX_IDX, +}; + +struct rpmi_clk_context { + struct device *dev; + struct mbox_chan *chan; + struct mbox_client client; +}; + +union rpmi_clk_rate { + struct { + u32 lo; + u32 hi; + } discrete[RPMI_CLK_MAX_NUM_RATES]; + struct { + u32 min_lo; + u32 min_hi; + u32 max_lo; + u32 max_hi; + u32 step_lo; + u32 step_hi; + } linear; +}; + +union rpmi_clk_rates { + u64 discrete[RPMI_CLK_MAX_NUM_RATES]; + struct { + u64 min; + u64 max; + u64 step; + } linear; +}; + +struct rpmi_clk { + struct rpmi_clk_context *context; + u32 id; + u32 num_rates; + u32 transition_latency; + enum rpmi_clk_type type; + union rpmi_clk_rates *rates; + char name[RPMI_CLK_NAME_LEN]; + struct clk_hw hw; +}; + +#define to_rpmi_clk(clk) container_of(clk, struct rpmi_clk, hw) + +struct rpmi_get_num_clocks_rx { + s32 status; + u32 num_clocks; +}; + +struct rpmi_get_attrs_tx { + u32 clkid; +}; + +struct rpmi_get_attrs_rx { + s32 status; + u32 flags; + u32 num_rates; + u32 transition_latency; + char name[RPMI_CLK_NAME_LEN]; +}; + +struct rpmi_get_supp_rates_tx { + u32 clkid; + u32 clk_rate_idx; +}; + +struct rpmi_get_supp_rates_rx { + u32 status; + u32 flags; + u32 remaining; + u32 returned; + union rpmi_clk_rate rates; +}; + +struct rpmi_get_rate_tx { + u32 clkid; +}; + +struct rpmi_get_rate_rx { + u32 status; + u32 lo; + u32 hi; +}; + +struct rpmi_set_rate_tx { + u32 clkid; + u32 flags; + u32 lo; + u32 hi; +}; + +struct rpmi_set_rate_rx { + u32 status; +}; + +struct rpmi_set_config_tx { + u32 clkid; + u32 config; +}; + +struct rpmi_set_config_rx { + u32 status; +}; + +static int rpmi_clk_get_num_clocks(struct rpmi_clk_context *context) +{ + struct rpmi_get_num_clocks_rx rx; + struct rpmi_mbox_message msg; + int ret; + + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_GET_NUM_CLOCKS, + NULL, 0, &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + if (rx.status) + return rpmi_to_linux_error(rx.status); + + return rx.num_clocks; +} + +/** + * Get the RPMI Clock Attributes. + * These attributes belong to a particular clock(clkid) + * which are different from the MPXY channel attributes. + */ +static int rpmi_clk_get_attrs(u32 clkid, struct rpmi_clk *rpmi_clk) +{ + struct rpmi_clk_context *context = rpmi_clk->context; + struct rpmi_mbox_message msg; + struct rpmi_get_attrs_tx tx; + struct rpmi_get_attrs_rx rx; + u8 format; + int ret; + + tx.clkid = cpu_to_le32(clkid); + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_GET_ATTRIBUTES, + &tx, sizeof(tx), &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + if (rx.status) + return rpmi_to_linux_error(rx.status); + + rpmi_clk->id = clkid; + rpmi_clk->num_rates = rx.num_rates; + rpmi_clk->transition_latency = rx.transition_latency; + strscpy(rpmi_clk->name, rx.name, RPMI_CLK_NAME_LEN); + + format = rx.flags & 1U; + if (format >= RPMI_CLK_TYPE_MAX_IDX) + return -EINVAL; + + rpmi_clk->type = format; + + return 0; +} + +static int rpmi_clk_get_supported_rates(u32 clkid, struct rpmi_clk *rpmi_clk) +{ + struct rpmi_clk_context *context = rpmi_clk->context; + struct rpmi_get_supp_rates_tx tx; + struct rpmi_get_supp_rates_rx rx; + struct rpmi_mbox_message msg; + size_t clk_rate_idx = 0; + int ret, rateidx, j; + + tx.clkid = cpu_to_le32(clkid); + tx.clk_rate_idx = 0; + + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_GET_SUPPORTED_RATES, + &tx, sizeof(tx), &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + if (rx.status) + return rpmi_to_linux_error(rx.status); + if (!rx.returned) + return -EINVAL; + + if (rpmi_clk->type == RPMI_CLK_DISCRETE) { + for (rateidx = 0; rateidx < rx.returned; rateidx++) { + rpmi_clk->rates->discrete[rateidx] = + GET_RATE_U64(rx.rates.discrete[rateidx].hi, + rx.rates.discrete[rateidx].lo); + } + + while (rx.remaining) { + clk_rate_idx += rx.returned; + tx.clk_rate_idx = clk_rate_idx; + + rpmi_mbox_init_send_with_response(&msg, + RPMI_CLK_SRV_GET_SUPPORTED_RATES, + &tx, sizeof(tx), &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + + for (j = 0; j < rx.returned; j++) { + if (rateidx >= (clk_rate_idx + rx.returned)) + break; + rpmi_clk->rates->discrete[rateidx++] = + GET_RATE_U64(rx.rates.discrete[j].hi, + rx.rates.discrete[j].lo); + } + } + } else if (rpmi_clk->type == RPMI_CLK_LINEAR) { + rpmi_clk->rates->linear.min = + GET_RATE_U64(rx.rates.linear.min_hi, + rx.rates.linear.min_lo); + rpmi_clk->rates->linear.max = + GET_RATE_U64(rx.rates.linear.max_hi, + rx.rates.linear.max_lo); + rpmi_clk->rates->linear.step = + GET_RATE_U64(rx.rates.linear.step_hi, + rx.rates.linear.step_lo); + } + + return 0; +} + +static unsigned long rpmi_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct rpmi_clk *rpmi_clk = to_rpmi_clk(hw); + struct rpmi_clk_context *context = rpmi_clk->context; + struct rpmi_mbox_message msg; + struct rpmi_get_rate_tx tx; + struct rpmi_get_rate_rx rx; + int ret; + + tx.clkid = cpu_to_le32(rpmi_clk->id); + + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_GET_RATE, + &tx, sizeof(tx), &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + if (rx.status) + return rx.status; + + return GET_RATE_U64(rx.hi, rx.lo); +} + +static long rpmi_clk_round_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate) +{ + struct rpmi_clk *rpmi_clk = to_rpmi_clk(hw); + u64 fmin, fmax, ftmp; + + if (rpmi_clk->type == RPMI_CLK_DISCRETE) + return rate; + + fmin = rpmi_clk->rates->linear.min; + fmax = rpmi_clk->rates->linear.max; + + if (rate <= fmin) + return fmin; + else if (rate >= fmax) + return fmax; + + ftmp = rate - fmin; + ftmp += rpmi_clk->rates->linear.step - 1; + do_div(ftmp, rpmi_clk->rates->linear.step); + + return ftmp * rpmi_clk->rates->linear.step + fmin; +} + +static int rpmi_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct rpmi_clk *rpmi_clk = to_rpmi_clk(hw); + struct rpmi_clk_context *context = rpmi_clk->context; + struct rpmi_mbox_message msg; + struct rpmi_set_rate_tx tx; + struct rpmi_set_rate_rx rx; + int ret; + + tx.clkid = cpu_to_le32(rpmi_clk->id); + tx.lo = cpu_to_le32(GET_RATE_LO_U32(rate)); + tx.hi = cpu_to_le32(GET_RATE_HI_U32(rate)); + + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_SET_RATE, + &tx, sizeof(tx), &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + if (rx.status) + return rpmi_to_linux_error(rx.status); + + return 0; +} + +static int rpmi_clk_enable(struct clk_hw *hw) +{ + struct rpmi_clk *rpmi_clk = to_rpmi_clk(hw); + struct rpmi_clk_context *context = rpmi_clk->context; + struct rpmi_mbox_message msg; + struct rpmi_set_config_tx tx; + struct rpmi_set_config_rx rx; + int ret; + + tx.config = cpu_to_le32(RPMI_CLK_ENABLE); + tx.clkid = cpu_to_le32(rpmi_clk->id); + + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_SET_CONFIG, + &tx, sizeof(tx), &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + if (rx.status) + return rpmi_to_linux_error(rx.status); + + return 0; +} + +static void rpmi_clk_disable(struct clk_hw *hw) +{ + struct rpmi_clk *rpmi_clk = to_rpmi_clk(hw); + struct rpmi_clk_context *context = rpmi_clk->context; + struct rpmi_mbox_message msg; + struct rpmi_set_config_tx tx; + struct rpmi_set_config_rx rx; + int ret; + + tx.config = cpu_to_le32(RPMI_CLK_DISABLE); + tx.clkid = cpu_to_le32(rpmi_clk->id); + + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_SET_CONFIG, + &tx, sizeof(tx), &rx, sizeof(rx)); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret || rx.status) + pr_err("Failed to disable clk-%u\n", rpmi_clk->id); +} + +static const struct clk_ops rpmi_clk_ops = { + .recalc_rate = rpmi_clk_recalc_rate, + .round_rate = rpmi_clk_round_rate, + .set_rate = rpmi_clk_set_rate, + .prepare = rpmi_clk_enable, + .unprepare = rpmi_clk_disable, +}; + +static struct clk_hw *rpmi_clk_enumerate(struct rpmi_clk_context *context, u32 clkid) +{ + struct device *dev = context->dev; + unsigned long min_rate, max_rate; + union rpmi_clk_rates *rates; + struct rpmi_clk *rpmi_clk; + struct clk_init_data init; + struct clk_hw *clk_hw; + int ret; + + rates = devm_kzalloc(dev, sizeof(union rpmi_clk_rates), GFP_KERNEL); + if (!rates) + return ERR_PTR(-ENOMEM); + + rpmi_clk = devm_kzalloc(dev, sizeof(struct rpmi_clk), GFP_KERNEL); + if (!rpmi_clk) + return ERR_PTR(-ENOMEM); + rpmi_clk->context = context; + rpmi_clk->rates = rates; + + ret = rpmi_clk_get_attrs(clkid, rpmi_clk); + if (ret) { + dev_err(dev, "Failed to get clk-%u attributes\n", clkid); + return ERR_PTR(ret); + } + + ret = rpmi_clk_get_supported_rates(clkid, rpmi_clk); + if (ret) { + dev_err(dev, "Get supported rates failed for clk-%u, %d\n", + clkid, ret); + return ERR_PTR(ret); + } + + init.flags = CLK_GET_RATE_NOCACHE; + init.num_parents = 0; + init.ops = &rpmi_clk_ops; + init.name = rpmi_clk->name; + clk_hw = &rpmi_clk->hw; + clk_hw->init = &init; + + ret = devm_clk_hw_register(dev, clk_hw); + if (ret) { + dev_err(dev, "Unable to register clk-%u\n", clkid); + return ERR_PTR(ret); + } + + if (rpmi_clk->type == RPMI_CLK_DISCRETE) { + min_rate = rpmi_clk->rates->discrete[0]; + max_rate = rpmi_clk->rates->discrete[rpmi_clk->num_rates - 1]; + } else { + min_rate = rpmi_clk->rates->linear.min; + max_rate = rpmi_clk->rates->linear.max; + } + + clk_hw_set_rate_range(clk_hw, min_rate, max_rate); + + return NULL; +} + +static void rpmi_clk_receive_message(struct mbox_client *cl, void *msg) +{ + /* Nothing to do here. */ +} + +static int rpmi_clk_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct clk_hw_onecell_data *clk_data; + struct rpmi_clk_context *context; + struct rpmi_mbox_message msg; + int ret, num_clocks, i; + struct clk_hw *hw_ptr; + + /* Allocate RPMI clock context */ + context = devm_kzalloc(dev, sizeof(*context), GFP_KERNEL); + if (!context) + return -ENOMEM; + context->dev = dev; + platform_set_drvdata(pdev, context); + + /* Setup mailbox client */ + context->client.dev = context->dev; + context->client.rx_callback = rpmi_clk_receive_message; + context->client.tx_block = false; + context->client.knows_txdone = true; + context->client.tx_tout = 0; + + /* Request mailbox channel */ + context->chan = mbox_request_channel(&context->client, 0); + if (IS_ERR(context->chan)) + return PTR_ERR(context->chan); + + /* Validate RPMI specification version */ + rpmi_mbox_init_get_attribute(&msg, RPMI_MBOX_ATTR_SPEC_VERSION); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) { + dev_err(dev, "Failed to get spec version\n"); + goto fail_free_channel; + } + if (msg.attr.value < RPMI_MKVER(1, 0)) { + dev_err(dev, + "msg protocol version mismatch, expected 0x%x, found 0x%x\n", + RPMI_MKVER(1, 0), msg.attr.value); + ret = -EINVAL; + goto fail_free_channel; + } + + /* Validate clock service group ID */ + rpmi_mbox_init_get_attribute(&msg, RPMI_MBOX_ATTR_SERVICEGROUP_ID); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) { + dev_err(dev, "Failed to get service group ID\n"); + goto fail_free_channel; + } + if (msg.attr.value != RPMI_SRVGRP_CLOCK) { + dev_err(dev, + "service group match failed, expected 0x%x, found 0x%x\n", + RPMI_SRVGRP_CLOCK, msg.attr.value); + ret = -EINVAL; + goto fail_free_channel; + } + + /* Validate clock service group version */ + rpmi_mbox_init_get_attribute(&msg, RPMI_MBOX_ATTR_SERVICEGROUP_VERSION); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) { + dev_err(dev, "Failed to get service group version\n"); + goto fail_free_channel; + } + if (msg.attr.value < RPMI_MKVER(1, 0)) { + dev_err(dev, + "service group version failed, expected 0x%x, found 0x%x\n", + RPMI_MKVER(1, 0), msg.attr.value); + ret = -EINVAL; + goto fail_free_channel; + } + + /* Find-out number of clocks */ + num_clocks = rpmi_clk_get_num_clocks(context); + if (!num_clocks) { + dev_err(dev, "No clocks found\n"); + ret = -ENODEV; + goto fail_free_channel; + } + + /* Allocate clock data */ + clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, num_clocks), + GFP_KERNEL); + if (!clk_data) { + ret = -ENOMEM; + goto fail_free_channel; + } + clk_data->num = num_clocks; + + /* Setup clock data */ + for (i = 0; i < clk_data->num; i++) { + hw_ptr = rpmi_clk_enumerate(context, i); + if (IS_ERR(hw_ptr)) { + dev_err(dev, "failed to register clk-%d\n", i); + ret = PTR_ERR(hw_ptr); + goto fail_free_channel; + } + clk_data->hws[i] = hw_ptr; + } + + /* Register clock HW provider */ + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data); + if (ret) { + dev_err(dev, "failed to register clock HW provider\n"); + goto fail_free_channel; + } + + dev_info(dev, "clk HW provider registered with %d clocks\n", + num_clocks); + return 0; + +fail_free_channel: + mbox_free_channel(context->chan); + return ret; +} + +static void rpmi_clk_remove(struct platform_device *pdev) +{ + struct rpmi_clk_context *context = platform_get_drvdata(pdev); + + mbox_free_channel(context->chan); +} + +static const struct of_device_id rpmi_clk_of_match[] = { + { .compatible = "riscv,rpmi-clock" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, rpmi_clk_of_match); + +static struct platform_driver rpmi_clk_driver = { + .driver = { + .name = "riscv-rpmi-clock", + .of_match_table = rpmi_clk_of_match, + }, + .probe = rpmi_clk_probe, + .remove = rpmi_clk_remove, +}; +module_platform_driver(rpmi_clk_driver); + +MODULE_AUTHOR("Rahul Pathak <rpathak@xxxxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("Clock Driver based on RPMI message protocol"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/mailbox/riscv-rpmi-message.h b/include/linux/mailbox/riscv-rpmi-message.h index 8f4b3a0edbce..4e9478c4c0a3 100644 --- a/include/linux/mailbox/riscv-rpmi-message.h +++ b/include/linux/mailbox/riscv-rpmi-message.h @@ -89,6 +89,22 @@ static inline int rpmi_to_linux_error(int rpmi_error) } } +/** RPMI service group IDs */ +#define RPMI_SRVGRP_CLOCK 0x00007 + +/** RPMI clock service IDs */ +enum rpmi_clock_service_id { + RPMI_CLK_SRV_ENABLE_NOTIFICATION = 0x01, + RPMI_CLK_SRV_GET_NUM_CLOCKS = 0x02, + RPMI_CLK_SRV_GET_ATTRIBUTES = 0x03, + RPMI_CLK_SRV_GET_SUPPORTED_RATES = 0x04, + RPMI_CLK_SRV_SET_CONFIG = 0x05, + RPMI_CLK_SRV_GET_CONFIG = 0x06, + RPMI_CLK_SRV_SET_RATE = 0x07, + RPMI_CLK_SRV_GET_RATE = 0x08, + RPMI_CLK_SRV_ID_MAX_COUNT, +}; + /** RPMI linux mailbox attribute IDs */ enum rpmi_mbox_attribute_id { RPMI_MBOX_ATTR_SPEC_VERSION = 0, -- 2.43.0