This algorithm computes bus parameters like clock frequency, frame shape and port transport parameters based on active stream(s) running on the bus.

Developers can also implement their own .compute_params() callback for specific resource management algorithm, and set if before calling sdw_add_bus_master()

Credits: this patch is based on an earlier internal contribution by Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah. All hard-coded values were removed from the initial contribution to use BIOS information instead.

Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/Kconfig | 5 + drivers/soundwire/Makefile | 3 + drivers/soundwire/bus.c | 6 + drivers/soundwire/bus.h | 46 +- .../soundwire/generic_bandwidth_allocation.c | 427 ++++++++++++++++++ drivers/soundwire/intel.c | 3 + drivers/soundwire/stream.c | 12 + include/linux/soundwire/sdw.h | 3 + 8 files changed, 503 insertions(+), 2 deletions(-) create mode 100644 drivers/soundwire/generic_bandwidth_allocation.c

diff --git a/drivers/soundwire/Kconfig b/drivers/soundwire/Kconfig index f83d02c9c60a..016e74230bb7 100644 --- a/drivers/soundwire/Kconfig +++ b/drivers/soundwire/Kconfig @@ -24,6 +24,7 @@ config SOUNDWIRE_CADENCE config SOUNDWIRE_INTEL tristate "Intel SoundWire Master driver" select SOUNDWIRE_CADENCE + select SOUNDWIRE_GENERIC_ALLOCATION depends on ACPI && SND_SOC help SoundWire Intel Master driver. @@ -40,4 +41,8 @@ config SOUNDWIRE_QCOM If you have an Qualcomm platform which has a SoundWire Master then enable this config option to get the SoundWire support for that device + +config SOUNDWIRE_GENERIC_ALLOCATION + tristate + endif diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile index 7c53ffae9f50..bf1e250d50dd 100644 --- a/drivers/soundwire/Makefile +++ b/drivers/soundwire/Makefile @@ -8,6 +8,9 @@ soundwire-bus-y := bus_type.o bus.o master.o slave.o mipi_disco.o stream.o \ sysfs_slave.o sysfs_slave_dpn.o obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o

+soundwire-generic-allocation-objs := generic_bandwidth_allocation.o +obj-$(CONFIG_SOUNDWIRE_GENERIC_ALLOCATION) += soundwire-generic-allocation.o + ifdef CONFIG_DEBUG_FS soundwire-bus-y += debugfs.o endif diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index d808f0256ba0..11c5a402afcd 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -61,6 +61,12 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent, return -EINVAL; }

+ if (!bus->compute_params) { + dev_err(bus->dev, + "Bandwidth allocation not configured, compute_params no set\n"); + return -EINVAL; + } + mutex_init(&bus->msg_lock); mutex_init(&bus->bus_lock); INIT_LIST_HEAD(&bus->slaves); diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h index 82484f741168..d2fda8c69f0d 100644 --- a/drivers/soundwire/bus.h +++ b/drivers/soundwire/bus.h @@ -69,6 +69,7 @@ struct sdw_msg { };

#define SDW_DOUBLE_RATE_FACTOR 2 +#define SDW_STRM_RATE_GROUPING 1

extern int sdw_rows[SDW_FRAME_ROWS]; extern int sdw_cols[SDW_FRAME_COLS]; @@ -154,9 +155,50 @@ int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg, int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave, u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf);

+/* Retrieve and return channel count from channel mask */ +static inline int sdw_ch_mask_to_ch(int ch_mask) +{ + int c = 0; + + for (c = 0; ch_mask; ch_mask >>= 1) + c += ch_mask & 1; + + return c; +} + +/* Fill transport parameter data structure */ +static inline void sdw_fill_xport_params(struct sdw_transport_params *params, + int port_num, bool grp_ctrl_valid, + int grp_ctrl, int sample_int, + int off1, int off2, + int hstart, int hstop, + int pack_mode, int lane_ctrl) +{ + params->port_num = port_num; + params->blk_grp_ctrl_valid = grp_ctrl_valid; + params->blk_grp_ctrl = grp_ctrl; + params->sample_interval = sample_int; + params->offset1 = off1; + params->offset2 = off2; + params->hstart = hstart; + params->hstop = hstop; + params->blk_pkg_mode = pack_mode; + params->lane_ctrl = lane_ctrl; +} + +/* Fill port parameter data structure */ +static inline void sdw_fill_port_params(struct sdw_port_params *params, + int port_num, int bps, + int flow_mode, int data_mode) +{ + params->num = port_num; + params->bps = bps; + params->flow_mode = flow_mode; + params->data_mode = data_mode; +} + /* Read-Modify-Write Slave register */ -static inline int -sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val) +static inline int sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val) { int tmp;

diff --git a/drivers/soundwire/generic_bandwidth_allocation.c b/drivers/soundwire/generic_bandwidth_allocation.c new file mode 100644 index 000000000000..6088775b67a5 --- /dev/null +++ b/drivers/soundwire/generic_bandwidth_allocation.c @@ -0,0 +1,427 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) +// Copyright(c) 2015-2020 Intel Corporation. + +/* + * Bandwidth management algorithm based on 2^n gears + * + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/slab.h> +#include <linux/soundwire/sdw.h> +#include "bus.h" + +#define SDW_STRM_RATE_GROUPING 1 + +struct sdw_group_params { + unsigned int rate; + int full_bw; + int payload_bw; + int hwidth; +}; + +struct sdw_group { + unsigned int count; + unsigned int max_size; + unsigned int *rates; +}; + +struct sdw_transport_data { + int hstart; + int hstop; + int block_offset; + int sub_block_offset; +}; + +static void sdw_compute_slave_ports(struct sdw_master_runtime *m_rt, + struct sdw_transport_data *t_data) +{ + struct sdw_slave_runtime *s_rt = NULL; + struct sdw_port_runtime *p_rt; + int port_bo, sample_int; + unsigned int rate, bps, ch = 0; + unsigned int slave_total_ch; + + port_bo = t_data->block_offset; + + list_for_each_entry(s_rt, &m_rt->slave_rt_list, m_rt_node) { + rate = m_rt->stream->params.rate; + bps = m_rt->stream->params.bps; + sample_int = (m_rt->bus->params.curr_dr_freq / rate); + slave_total_ch = 0; + + list_for_each_entry(p_rt, &s_rt->port_list, port_node) { + ch = sdw_ch_mask_to_ch(p_rt->ch_mask); + + sdw_fill_xport_params(&p_rt->transport_params, + p_rt->num, false, + SDW_BLK_GRP_CNT_1, + sample_int, port_bo, port_bo >> 8, + t_data->hstart, + t_data->hstop, + (SDW_BLK_GRP_CNT_1 * ch), 0x0); + + sdw_fill_port_params(&p_rt->port_params, + p_rt->num, bps, + SDW_PORT_FLOW_MODE_ISOCH, + SDW_PORT_DATA_MODE_NORMAL); + + port_bo += bps * ch; + slave_total_ch += ch; + } + + if (m_rt->direction == SDW_DATA_DIR_TX && + m_rt->ch_count == slave_total_ch) { + /* + * Slave devices were configured to access all channels + * of the stream, which indicates that they operate in + * 'mirror mode'. Make sure we reset the port offset for + * the next device in the list + */ + port_bo = t_data->block_offset; + } + } +} + +static void sdw_compute_master_ports(struct sdw_master_runtime *m_rt, + struct sdw_group_params *params, + int port_bo, int hstop) +{ + struct sdw_transport_data t_data = {0}; + struct sdw_port_runtime *p_rt; + struct sdw_bus *bus = m_rt->bus; + int sample_int, hstart = 0; + unsigned int rate, bps, ch, no_ch; + + rate = m_rt->stream->params.rate; + bps = m_rt->stream->params.bps; + ch = m_rt->ch_count; + sample_int = (bus->params.curr_dr_freq / rate); + + if (rate != params->rate) + return; + + t_data.hstop = hstop; + hstart = hstop - params->hwidth + 1; + t_data.hstart = hstart; + + list_for_each_entry(p_rt, &m_rt->port_list, port_node) { + no_ch = sdw_ch_mask_to_ch(p_rt->ch_mask); + + sdw_fill_xport_params(&p_rt->transport_params, p_rt->num, + false, SDW_BLK_GRP_CNT_1, sample_int, + port_bo, port_bo >> 8, hstart, hstop, + (SDW_BLK_GRP_CNT_1 * no_ch), 0x0); + + sdw_fill_port_params(&p_rt->port_params, + p_rt->num, bps, + SDW_PORT_FLOW_MODE_ISOCH, + SDW_PORT_DATA_MODE_NORMAL); + + /* Check for first entry */ + if (!(p_rt == list_first_entry(&m_rt->port_list, + struct sdw_port_runtime, + port_node))) { + port_bo += bps * ch; + continue; + } + + t_data.hstart = hstart; + t_data.hstop = hstop; + t_data.block_offset = port_bo; + t_data.sub_block_offset = 0; + port_bo += bps * ch; + } + + sdw_compute_slave_ports(m_rt, &t_data); +} + +static void _sdw_compute_port_params(struct sdw_bus *bus, + struct sdw_group_params *params, int count) +{ + struct sdw_master_runtime *m_rt = NULL; + int hstop = bus->params.col - 1; + int block_offset, port_bo, i; + + /* Run loop for all groups to compute transport parameters */ + for (i = 0; i < count; i++) { + port_bo = 1; + block_offset = 1; + + list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) { + sdw_compute_master_ports(m_rt, &params[i], + port_bo, hstop); + + block_offset += m_rt->ch_count * + m_rt->stream->params.bps; + port_bo = block_offset; + } + + hstop = hstop - params[i].hwidth; + } +} + +static int sdw_compute_group_params(struct sdw_bus *bus, + struct sdw_group_params *params, + int *rates, int count) +{ + struct sdw_master_runtime *m_rt = NULL; + int sel_col = bus->params.col; + unsigned int rate, bps, ch; + int i, column_needed = 0; + + /* Calculate bandwidth per group */ + for (i = 0; i < count; i++) { + params[i].rate = rates[i]; + params[i].full_bw = bus->params.curr_dr_freq / params[i].rate; + } + + list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) { + rate = m_rt->stream->params.rate; + bps = m_rt->stream->params.bps; + ch = m_rt->ch_count; + + for (i = 0; i < count; i++) { + if (rate == params[i].rate) + params[i].payload_bw += bps * ch; + } + } + + for (i = 0; i < count; i++) { + params[i].hwidth = (sel_col * + params[i].payload_bw + params[i].full_bw - 1) / + params[i].full_bw; + + column_needed += params[i].hwidth; + } + + if (column_needed > sel_col - 1) + return -EINVAL; + + return 0; +} + +static int sdw_add_element_group_count(struct sdw_group *group, + unsigned int rate) +{ + int num = group->count; + int i; + + for (i = 0; i <= num; i++) { + if (rate == group->rates[i]) + break; + + if (i != num) + continue; + + if (group->count >= group->max_size) { + unsigned int *rates; + + group->max_size += 1; + rates = krealloc(group->rates, + (sizeof(int) * group->max_size), + GFP_KERNEL); + if (!rates) + return -ENOMEM; + group->rates = rates; + } + + group->rates[group->count++] = rate; + } + + return 0; +} + +static int sdw_get_group_count(struct sdw_bus *bus, + struct sdw_group *group) +{ + struct sdw_master_runtime *m_rt; + unsigned int rate; + int ret = 0; + + group->count = 0; + group->max_size = SDW_STRM_RATE_GROUPING; + group->rates = kcalloc(group->max_size, sizeof(int), GFP_KERNEL); + if (!group->rates) + return -ENOMEM; + + list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) { + rate = m_rt->stream->params.rate; + if (m_rt == list_first_entry(&bus->m_rt_list, + struct sdw_master_runtime, + bus_node)) { + group->rates[group->count++] = rate; + + } else { + ret = sdw_add_element_group_count(group, rate); + if (ret < 0) { + kfree(group->rates); + return ret; + } + } + } + + return ret; +} + +/** + * sdw_compute_port_params: Compute transport and port parameters + * + * @bus: SDW Bus instance + */ +static int sdw_compute_port_params(struct sdw_bus *bus) +{ + struct sdw_group_params *params = NULL; + struct sdw_group group; + int ret; + + ret = sdw_get_group_count(bus, &group); + if (ret < 0) + return ret; + + if (group.count == 0) + goto out; + + params = kcalloc(group.count, sizeof(*params), GFP_KERNEL); + if (!params) { + ret = -ENOMEM; + goto out; + } + + /* Compute transport parameters for grouped streams */ + ret = sdw_compute_group_params(bus, params, + &group.rates[0], group.count); + if (ret < 0) + goto free_params; + + _sdw_compute_port_params(bus, params, group.count); + +free_params: + kfree(params); +out: + kfree(group.rates); + + return ret; +} + +static int sdw_select_row_col(struct sdw_bus *bus, int clk_freq) +{ + struct sdw_master_prop *prop = &bus->prop; + int frame_int, frame_freq; + int r, c; + + for (c = 0; c < SDW_FRAME_COLS; c++) { + for (r = 0; r < SDW_FRAME_ROWS; r++) { + if (sdw_rows[r] != prop->default_row || + sdw_cols[c] != prop->default_col) + continue; + + frame_int = sdw_rows[r] * sdw_cols[c]; + frame_freq = clk_freq / frame_int; + + if ((clk_freq - (frame_freq * SDW_FRAME_CTRL_BITS)) < + bus->params.bandwidth) + continue; + + bus->params.row = sdw_rows[r]; + bus->params.col = sdw_cols[c]; + return 0; + } + } + + return -EINVAL; +} + +/** + * sdw_compute_bus_params: Compute bus parameters + * + * @bus: SDW Bus instance + */ +static int sdw_compute_bus_params(struct sdw_bus *bus) +{ + unsigned int max_dr_freq, curr_dr_freq = 0; + struct sdw_master_prop *mstr_prop = NULL; + int i, clk_values, ret; + bool is_gear = false; + u32 *clk_buf; + + mstr_prop = &bus->prop; + if (!mstr_prop) + return -EINVAL; + + if (mstr_prop->num_clk_gears) { + clk_values = mstr_prop->num_clk_gears; + clk_buf = mstr_prop->clk_gears; + is_gear = true; + } else if (mstr_prop->num_clk_freq) { + clk_values = mstr_prop->num_clk_freq; + clk_buf = mstr_prop->clk_freq; + } else { + clk_values = 1; + clk_buf = NULL; + } + + max_dr_freq = mstr_prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR; + + for (i = 0; i < clk_values; i++) { + if (!clk_buf) + curr_dr_freq = max_dr_freq; + else + curr_dr_freq = (is_gear) ? + (max_dr_freq >> clk_buf[i]) : + clk_buf[i] * SDW_DOUBLE_RATE_FACTOR; + + if (curr_dr_freq <= bus->params.bandwidth) + continue; + + break; + + /* + * TODO: Check all the Slave(s) port(s) audio modes and find + * whether given clock rate is supported with glitchless + * transition. + */ + } + + if (i == clk_values) + return -EINVAL; + + ret = sdw_select_row_col(bus, curr_dr_freq); + if (ret < 0) + return -EINVAL; + + bus->params.curr_dr_freq = curr_dr_freq; + return 0; +} + +/** + * sdw_compute_params: Compute bus, transport and port parameters + * + * @bus: SDW Bus instance + */ +int sdw_compute_params(struct sdw_bus *bus) +{ + int ret; + + /* Computes clock frequency, frame shape and frame frequency */ + ret = sdw_compute_bus_params(bus); + if (ret < 0) { + dev_err(bus->dev, "Compute bus params failed: %d", ret); + return ret; + } + + /* Compute transport and port params */ + ret = sdw_compute_port_params(bus); + if (ret < 0) { + dev_err(bus->dev, "Compute transport params failed: %d", ret); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(sdw_compute_params); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_DESCRIPTION("SoundWire Generic Bandwidth Allocation"); diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index e047910d73f5..1211d114ff59 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -1318,6 +1318,9 @@ static int intel_master_probe(struct platform_device *pdev) /* set driver data, accessed by snd_soc_dai_get_drvdata() */ dev_set_drvdata(dev, cdns);

+ /* use generic bandwidth allocation algorithm */ + sdw->cdns.bus.compute_params = sdw_compute_params; + ret = sdw_bus_master_add(bus, dev, dev->fwnode); if (ret) { dev_err(dev, "sdw_bus_master_add fail: %d\n", ret); diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c index b8b1973e3ee2..f3219d1fa63b 100644 --- a/drivers/soundwire/stream.c +++ b/drivers/soundwire/stream.c @@ -25,8 +25,10 @@ int sdw_rows[SDW_FRAME_ROWS] = {48, 50, 60, 64, 75, 80, 125, 147, 96, 100, 120, 128, 150, 160, 250, 0, 192, 200, 240, 256, 72, 144, 90, 180}; +EXPORT_SYMBOL(sdw_rows);

int sdw_cols[SDW_FRAME_COLS] = {2, 4, 6, 8, 10, 12, 14, 16}; +EXPORT_SYMBOL(sdw_cols);

int sdw_find_col_index(int col) { @@ -1782,6 +1784,16 @@ static int _sdw_deprepare_stream(struct sdw_stream_runtime *stream) bus->params.bandwidth -= m_rt->stream->params.rate * m_rt->ch_count * m_rt->stream->params.bps;

+ /* Compute params */ + if (bus->compute_params) { + ret = bus->compute_params(bus); + if (ret < 0) { + dev_err(bus->dev, "Compute params failed: %d", + ret); + return ret; + } + } + /* Program params */ ret = sdw_program_params(bus, false); if (ret < 0) { diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index 1e9010c139f0..3fa1b18f7f97 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -955,6 +955,9 @@ struct sdw_stream_runtime {

struct sdw_stream_runtime *sdw_alloc_stream(const char *stream_name); void sdw_release_stream(struct sdw_stream_runtime *stream); + +int sdw_compute_params(struct sdw_bus *bus); + int sdw_stream_add_master(struct sdw_bus *bus, struct sdw_stream_config *stream_config, struct sdw_port_config *port_config,