diff options
Diffstat (limited to 'drivers/clk/clk-rpmi.c')
| -rw-r--r-- | drivers/clk/clk-rpmi.c | 620 |
1 files changed, 620 insertions, 0 deletions
diff --git a/drivers/clk/clk-rpmi.c b/drivers/clk/clk-rpmi.c new file mode 100644 index 000000000000..921296aafa68 --- /dev/null +++ b/drivers/clk/clk-rpmi.c @@ -0,0 +1,620 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RISC-V MPXY Based Clock Driver + * + * Copyright (C) 2025 Ventana Micro Systems Ltd. + */ + +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/mailbox_client.h> +#include <linux/mailbox/riscv-rpmi-message.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/wordpart.h> + +#define RPMI_CLK_DISCRETE_MAX_NUM_RATES 16 +#define RPMI_CLK_NAME_LEN 16 + +#define to_rpmi_clk(clk) container_of(clk, struct rpmi_clk, hw) + +enum rpmi_clk_config { + RPMI_CLK_DISABLE = 0, + RPMI_CLK_ENABLE = 1, + RPMI_CLK_CONFIG_MAX_IDX +}; + +#define RPMI_CLK_TYPE_MASK GENMASK(1, 0) +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; + u32 max_msg_data_size; +}; + +/* + * rpmi_clk_rates represents the rates format + * as specified by the RPMI specification. + * No other data format (e.g., struct linear_range) + * is required to avoid to and from conversion. + */ +union rpmi_clk_rates { + u64 discrete[RPMI_CLK_DISCRETE_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; +}; + +struct rpmi_clk_rate_discrete { + __le32 lo; + __le32 hi; +}; + +struct rpmi_clk_rate_linear { + __le32 min_lo; + __le32 min_hi; + __le32 max_lo; + __le32 max_hi; + __le32 step_lo; + __le32 step_hi; +}; + +struct rpmi_get_num_clocks_rx { + __le32 status; + __le32 num_clocks; +}; + +struct rpmi_get_attrs_tx { + __le32 clkid; +}; + +struct rpmi_get_attrs_rx { + __le32 status; + __le32 flags; + __le32 num_rates; + __le32 transition_latency; + char name[RPMI_CLK_NAME_LEN]; +}; + +struct rpmi_get_supp_rates_tx { + __le32 clkid; + __le32 clk_rate_idx; +}; + +struct rpmi_get_supp_rates_rx { + __le32 status; + __le32 flags; + __le32 remaining; + __le32 returned; + __le32 rates[]; +}; + +struct rpmi_get_rate_tx { + __le32 clkid; +}; + +struct rpmi_get_rate_rx { + __le32 status; + __le32 lo; + __le32 hi; +}; + +struct rpmi_set_rate_tx { + __le32 clkid; + __le32 flags; + __le32 lo; + __le32 hi; +}; + +struct rpmi_set_rate_rx { + __le32 status; +}; + +struct rpmi_set_config_tx { + __le32 clkid; + __le32 config; +}; + +struct rpmi_set_config_rx { + __le32 status; +}; + +static inline u64 rpmi_clkrate_u64(u32 __hi, u32 __lo) +{ + return (((u64)(__hi) << 32) | (u32)(__lo)); +} + +static u32 rpmi_clk_get_num_clocks(struct rpmi_clk_context *context) +{ + struct rpmi_get_num_clocks_rx rx, *resp; + 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 0; + + resp = rpmi_mbox_get_msg_response(&msg); + if (!resp || resp->status) + return 0; + + return le32_to_cpu(resp->num_clocks); +} + +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, *resp; + 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; + + resp = rpmi_mbox_get_msg_response(&msg); + if (!resp) + return -EINVAL; + if (resp->status) + return rpmi_to_linux_error(le32_to_cpu(resp->status)); + + rpmi_clk->id = clkid; + rpmi_clk->num_rates = le32_to_cpu(resp->num_rates); + rpmi_clk->transition_latency = le32_to_cpu(resp->transition_latency); + strscpy(rpmi_clk->name, resp->name, RPMI_CLK_NAME_LEN); + + format = le32_to_cpu(resp->flags) & RPMI_CLK_TYPE_MASK; + 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_clk_rate_discrete *rate_discrete; + struct rpmi_clk_rate_linear *rate_linear; + struct rpmi_get_supp_rates_tx tx; + struct rpmi_get_supp_rates_rx *resp; + struct rpmi_mbox_message msg; + size_t clk_rate_idx; + int ret, rateidx, j; + + tx.clkid = cpu_to_le32(clkid); + tx.clk_rate_idx = 0; + + /* + * Make sure we allocate rx buffer sufficient to be accommodate all + * the rates sent in one RPMI message. + */ + struct rpmi_get_supp_rates_rx *rx __free(kfree) = + kzalloc(context->max_msg_data_size, GFP_KERNEL); + if (!rx) + return -ENOMEM; + + rpmi_mbox_init_send_with_response(&msg, RPMI_CLK_SRV_GET_SUPPORTED_RATES, + &tx, sizeof(tx), rx, context->max_msg_data_size); + + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + + resp = rpmi_mbox_get_msg_response(&msg); + if (!resp) + return -EINVAL; + if (resp->status) + return rpmi_to_linux_error(le32_to_cpu(resp->status)); + if (!le32_to_cpu(resp->returned)) + return -EINVAL; + + if (rpmi_clk->type == RPMI_CLK_DISCRETE) { + rate_discrete = (struct rpmi_clk_rate_discrete *)resp->rates; + + for (rateidx = 0; rateidx < le32_to_cpu(resp->returned); rateidx++) { + rpmi_clk->rates->discrete[rateidx] = + rpmi_clkrate_u64(le32_to_cpu(rate_discrete[rateidx].hi), + le32_to_cpu(rate_discrete[rateidx].lo)); + } + + /* + * Keep sending the request message until all + * the rates are received. + */ + clk_rate_idx = 0; + while (le32_to_cpu(resp->remaining)) { + clk_rate_idx += le32_to_cpu(resp->returned); + tx.clk_rate_idx = cpu_to_le32(clk_rate_idx); + + rpmi_mbox_init_send_with_response(&msg, + RPMI_CLK_SRV_GET_SUPPORTED_RATES, + &tx, sizeof(tx), + rx, context->max_msg_data_size); + + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return ret; + + resp = rpmi_mbox_get_msg_response(&msg); + if (!resp) + return -EINVAL; + if (resp->status) + return rpmi_to_linux_error(le32_to_cpu(resp->status)); + if (!le32_to_cpu(resp->returned)) + return -EINVAL; + + for (j = 0; j < le32_to_cpu(resp->returned); j++) { + if (rateidx >= clk_rate_idx + le32_to_cpu(resp->returned)) + break; + rpmi_clk->rates->discrete[rateidx++] = + rpmi_clkrate_u64(le32_to_cpu(rate_discrete[j].hi), + le32_to_cpu(rate_discrete[j].lo)); + } + } + } else if (rpmi_clk->type == RPMI_CLK_LINEAR) { + rate_linear = (struct rpmi_clk_rate_linear *)resp->rates; + + rpmi_clk->rates->linear.min = rpmi_clkrate_u64(le32_to_cpu(rate_linear->min_hi), + le32_to_cpu(rate_linear->min_lo)); + rpmi_clk->rates->linear.max = rpmi_clkrate_u64(le32_to_cpu(rate_linear->max_hi), + le32_to_cpu(rate_linear->max_lo)); + rpmi_clk->rates->linear.step = rpmi_clkrate_u64(le32_to_cpu(rate_linear->step_hi), + le32_to_cpu(rate_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, *resp; + 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; + + resp = rpmi_mbox_get_msg_response(&msg); + if (!resp) + return -EINVAL; + if (resp->status) + return rpmi_to_linux_error(le32_to_cpu(resp->status)); + + return rpmi_clkrate_u64(le32_to_cpu(resp->hi), le32_to_cpu(resp->lo)); +} + +static int rpmi_clk_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct rpmi_clk *rpmi_clk = to_rpmi_clk(hw); + u64 fmin, fmax, ftmp; + + /* + * Keep the requested rate if the clock format + * is of discrete type. Let the platform which + * is actually controlling the clock handle that. + */ + if (rpmi_clk->type == RPMI_CLK_DISCRETE) + return 0; + + fmin = rpmi_clk->rates->linear.min; + fmax = rpmi_clk->rates->linear.max; + + if (req->rate <= fmin) { + req->rate = fmin; + return 0; + } else if (req->rate >= fmax) { + req->rate = fmax; + return 0; + } + + ftmp = req->rate - fmin; + ftmp += rpmi_clk->rates->linear.step - 1; + do_div(ftmp, rpmi_clk->rates->linear.step); + + req->rate = ftmp * rpmi_clk->rates->linear.step + fmin; + + return 0; +} + +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, *resp; + int ret; + + tx.clkid = cpu_to_le32(rpmi_clk->id); + tx.lo = cpu_to_le32(lower_32_bits(rate)); + tx.hi = cpu_to_le32(upper_32_bits(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; + + resp = rpmi_mbox_get_msg_response(&msg); + if (!resp) + return -EINVAL; + if (resp->status) + return rpmi_to_linux_error(le32_to_cpu(resp->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, *resp; + 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; + + resp = rpmi_mbox_get_msg_response(&msg); + if (!resp) + return -EINVAL; + if (resp->status) + return rpmi_to_linux_error(le32_to_cpu(resp->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; + + 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)); + + rpmi_mbox_send_message(context->chan, &msg); +} + +static const struct clk_ops rpmi_clk_ops = { + .recalc_rate = rpmi_clk_recalc_rate, + .determine_rate = rpmi_clk_determine_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(*rates), GFP_KERNEL); + if (!rates) + return ERR_PTR(-ENOMEM); + + rpmi_clk = devm_kzalloc(dev, sizeof(*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) + return dev_err_ptr_probe(dev, ret, + "Failed to get clk-%u attributes\n", + clkid); + + ret = rpmi_clk_get_supported_rates(clkid, rpmi_clk); + if (ret) + return dev_err_ptr_probe(dev, ret, + "Get supported rates failed for clk-%u\n", + clkid); + + 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) + return dev_err_ptr_probe(dev, ret, + "Unable to register clk-%u\n", + clkid); + + 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 clk_hw; +} + +static void rpmi_clk_mbox_chan_release(void *data) +{ + struct mbox_chan *chan = data; + + mbox_free_channel(chan); +} + +static int rpmi_clk_probe(struct platform_device *pdev) +{ + int ret; + unsigned int num_clocks, i; + struct clk_hw_onecell_data *clk_data; + struct rpmi_clk_context *context; + struct rpmi_mbox_message msg; + struct clk_hw *hw_ptr; + struct device *dev = &pdev->dev; + + context = devm_kzalloc(dev, sizeof(*context), GFP_KERNEL); + if (!context) + return -ENOMEM; + context->dev = dev; + platform_set_drvdata(pdev, context); + + context->client.dev = context->dev; + context->client.rx_callback = NULL; + context->client.tx_block = false; + context->client.knows_txdone = true; + context->client.tx_tout = 0; + + context->chan = mbox_request_channel(&context->client, 0); + if (IS_ERR(context->chan)) + return PTR_ERR(context->chan); + + ret = devm_add_action_or_reset(dev, rpmi_clk_mbox_chan_release, context->chan); + if (ret) + return dev_err_probe(dev, ret, "Failed to add rpmi mbox channel cleanup\n"); + + rpmi_mbox_init_get_attribute(&msg, RPMI_MBOX_ATTR_SPEC_VERSION); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return dev_err_probe(dev, ret, "Failed to get spec version\n"); + if (msg.attr.value < RPMI_MKVER(1, 0)) { + return dev_err_probe(dev, -EINVAL, + "msg protocol version mismatch, expected 0x%x, found 0x%x\n", + RPMI_MKVER(1, 0), msg.attr.value); + } + + rpmi_mbox_init_get_attribute(&msg, RPMI_MBOX_ATTR_SERVICEGROUP_ID); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return dev_err_probe(dev, ret, "Failed to get service group ID\n"); + if (msg.attr.value != RPMI_SRVGRP_CLOCK) { + return dev_err_probe(dev, -EINVAL, + "service group match failed, expected 0x%x, found 0x%x\n", + RPMI_SRVGRP_CLOCK, msg.attr.value); + } + + rpmi_mbox_init_get_attribute(&msg, RPMI_MBOX_ATTR_SERVICEGROUP_VERSION); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return dev_err_probe(dev, ret, "Failed to get service group version\n"); + if (msg.attr.value < RPMI_MKVER(1, 0)) { + return dev_err_probe(dev, -EINVAL, + "service group version failed, expected 0x%x, found 0x%x\n", + RPMI_MKVER(1, 0), msg.attr.value); + } + + rpmi_mbox_init_get_attribute(&msg, RPMI_MBOX_ATTR_MAX_MSG_DATA_SIZE); + ret = rpmi_mbox_send_message(context->chan, &msg); + if (ret) + return dev_err_probe(dev, ret, "Failed to get max message data size\n"); + + context->max_msg_data_size = msg.attr.value; + num_clocks = rpmi_clk_get_num_clocks(context); + if (!num_clocks) + return dev_err_probe(dev, -ENODEV, "No clocks found\n"); + + clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, num_clocks), + GFP_KERNEL); + if (!clk_data) + return dev_err_probe(dev, -ENOMEM, "No memory for clock data\n"); + clk_data->num = num_clocks; + + for (i = 0; i < clk_data->num; i++) { + hw_ptr = rpmi_clk_enumerate(context, i); + if (IS_ERR(hw_ptr)) { + return dev_err_probe(dev, PTR_ERR(hw_ptr), + "Failed to register clk-%d\n", i); + } + clk_data->hws[i] = hw_ptr; + } + + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data); + if (ret) + return dev_err_probe(dev, ret, "Failed to register clock HW provider\n"); + + return 0; +} + +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, +}; +module_platform_driver(rpmi_clk_driver); + +MODULE_AUTHOR("Rahul Pathak <rpathak@ventanamicro.com>"); +MODULE_DESCRIPTION("Clock Driver based on RPMI message protocol"); +MODULE_LICENSE("GPL"); |