freebsd-src/sys/dev/qcom_clk/qcom_clk_rcg2.c
Emmanuel Vadot be82b3a0bf clk: Move clock code in dev/clk
We've removed kernel option EXT_RESOURCES almost two years ago.
While it was ok to have some code under a common 'extres' subdirectory
at first, we now have a lot of consumer of it and we made it mandatory
so no need to have it under a cryptic name.

Reviewed by:	mhorne
Sponsored by:	Beckhoff Automation GmbH & Co. KG
Differential Revision:	https://reviews.freebsd.org/D43191
2024-01-10 19:20:26 +01:00

660 lines
18 KiB
C

/*-
* Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <machine/bus.h>
#include <dev/clk/clk.h>
#include <dev/clk/clk_div.h>
#include <dev/clk/clk_fixed.h>
#include <dev/clk/clk_mux.h>
#include "qcom_clk_freqtbl.h"
#include "qcom_clk_rcg2.h"
#include "qcom_clk_rcg2_reg.h"
#include "clkdev_if.h"
#if 0
#define DPRINTF(dev, msg...) device_printf(dev, msg);
#else
#define DPRINTF(dev, msg...)
#endif
#define QCOM_CLK_RCG2_CFG_OFFSET(sc) \
((sc)->cmd_rcgr + (sc)->cfg_offset + QCOM_CLK_RCG2_CFG_REG)
#define QCOM_CLK_RCG2_CMD_REGISTER(sc) \
((sc)->cmd_rcgr + QCOM_CLK_RCG2_CMD_REG)
#define QCOM_CLK_RCG2_M_OFFSET(sc) \
((sc)->cmd_rcgr + (sc)->cfg_offset + QCOM_CLK_RCG2_M_REG)
#define QCOM_CLK_RCG2_N_OFFSET(sc) \
((sc)->cmd_rcgr + (sc)->cfg_offset + QCOM_CLK_RCG2_N_REG)
#define QCOM_CLK_RCG2_D_OFFSET(sc) \
((sc)->cmd_rcgr + (sc)->cfg_offset + QCOM_CLK_RCG2_D_REG)
struct qcom_clk_rcg2_sc {
struct clknode *clknode;
uint32_t cmd_rcgr;
uint32_t hid_width;
uint32_t mnd_width;
int32_t safe_src_idx;
uint32_t cfg_offset;
int safe_pre_parent_idx;
uint32_t flags;
const struct qcom_clk_freq_tbl *freq_tbl;
};
/*
* Finish a clock update.
*
* This instructs the configuration to take effect.
*/
static bool
qcom_clk_rcg2_update_config_locked(struct qcom_clk_rcg2_sc *sc)
{
uint32_t reg, count;
/*
* Send "update" to the controller.
*/
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CMD_REGISTER(sc), &reg);
reg |= QCOM_CLK_RCG2_CMD_UPDATE;
CLKDEV_WRITE_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CMD_REGISTER(sc), reg);
wmb();
/*
* Poll for completion of update.
*/
for (count = 0; count < 1000; count++) {
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CMD_REGISTER(sc), &reg);
if ((reg & QCOM_CLK_RCG2_CMD_UPDATE) == 0) {
return (true);
}
DELAY(10);
rmb();
}
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CMD_REGISTER(sc), &reg);
DPRINTF(clknode_get_device(sc->clknode), "%s: failed; reg=0x%08x\n",
__func__, reg);
return (false);
}
/*
* Calculate the output frequency given an input frequency and the m/n:d
* configuration.
*/
static uint64_t
qcom_clk_rcg2_calc_rate(uint64_t rate, uint32_t mode, uint32_t m, uint32_t n,
uint32_t hid_div)
{
if (hid_div != 0) {
rate = rate * 2;
rate = rate / (hid_div + 1);
}
/* Note: assume n is not 0 here; bad things happen if it is */
if (mode != 0) {
rate = (rate * m) / n;
}
return (rate);
}
/*
* The inverse of calc_rate() - calculate the required input frequency
* given the desired output freqency and m/n:d configuration.
*/
static uint64_t
qcom_clk_rcg2_calc_input_freq(uint64_t freq, uint32_t m, uint32_t n,
uint32_t hid_div)
{
if (hid_div != 0) {
freq = freq / 2;
freq = freq * (hid_div + 1);
}
if (n != 0) {
freq = (freq * n) / m;
}
return (freq);
}
static int
qcom_clk_rcg2_recalc(struct clknode *clk, uint64_t *freq)
{
struct qcom_clk_rcg2_sc *sc;
uint32_t cfg, m = 0, n = 0, hid_div = 0;
uint32_t mode = 0, mask;
sc = clknode_get_softc(clk);
/* Read the MODE, CFG, M and N parameters */
CLKDEV_DEVICE_LOCK(clknode_get_device(sc->clknode));
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CFG_OFFSET(sc),
&cfg);
if (sc->mnd_width != 0) {
mask = (1U << sc->mnd_width) - 1;
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_M_OFFSET(sc), &m);
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_N_OFFSET(sc), &n);
m = m & mask;
n = ~ n;
n = n & mask;
n = n + m;
mode = (cfg & QCOM_CLK_RCG2_CFG_MODE_MASK)
>> QCOM_CLK_RCG2_CFG_MODE_SHIFT;
}
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
/* Fetch the divisor */
mask = (1U << sc->hid_width) - 1;
hid_div = (cfg >> QCOM_CLK_RCG2_CFG_SRC_DIV_SHIFT) & mask;
/* Calculate the rate based on the parent rate and config */
*freq = qcom_clk_rcg2_calc_rate(*freq, mode, m, n, hid_div);
return (0);
}
/*
* configure the mn:d divisor, pre-divisor, and parent.
*/
static void
qcom_clk_rcg2_set_config_locked(struct qcom_clk_rcg2_sc *sc,
const struct qcom_clk_freq_tbl *f, int parent_idx)
{
uint32_t mask, reg;
/* If we have MN:D, then update it */
if (sc->mnd_width != 0 && f->n != 0) {
mask = (1U << sc->mnd_width) - 1;
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_M_OFFSET(sc), &reg);
reg &= ~mask;
reg |= (f->m & mask);
CLKDEV_WRITE_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_M_OFFSET(sc), reg);
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_N_OFFSET(sc), &reg);
reg &= ~mask;
reg |= ((~(f->n - f->m)) & mask);
CLKDEV_WRITE_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_N_OFFSET(sc), reg);
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_D_OFFSET(sc), &reg);
reg &= ~mask;
reg |= ((~f->n) & mask);
CLKDEV_WRITE_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_D_OFFSET(sc), reg);
}
mask = (1U << sc->hid_width) - 1;
/*
* Mask out register fields we're going to modify along with
* the pre-divisor.
*/
mask |= QCOM_CLK_RCG2_CFG_SRC_SEL_MASK
| QCOM_CLK_RCG2_CFG_MODE_MASK
| QCOM_CLK_RCG2_CFG_HW_CLK_CTRL_MASK;
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CFG_OFFSET(sc), &reg);
reg &= ~mask;
/* Configure pre-divisor */
reg = reg | ((f->pre_div) << QCOM_CLK_RCG2_CFG_SRC_DIV_SHIFT);
/* Configure parent clock */
reg = reg | (((parent_idx << QCOM_CLK_RCG2_CFG_SRC_SEL_SHIFT)
& QCOM_CLK_RCG2_CFG_SRC_SEL_MASK));
/* Configure dual-edge if needed */
if (sc->mnd_width != 0 && f->n != 0 && (f->m != f->n))
reg |= QCOM_CLK_RCG2_CFG_MODE_DUAL_EDGE;
CLKDEV_WRITE_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CFG_OFFSET(sc), reg);
}
static int
qcom_clk_rcg2_init(struct clknode *clk, device_t dev)
{
struct qcom_clk_rcg2_sc *sc;
uint32_t reg;
uint32_t idx;
bool enabled __unused;
sc = clknode_get_softc(clk);
/*
* Read the mux setting to set the right parent.
* Whilst here, read the config to get whether we're enabled
* or not.
*/
CLKDEV_DEVICE_LOCK(clknode_get_device(sc->clknode));
/* check if rcg2 root clock is enabled */
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CMD_REGISTER(sc), &reg);
if (reg & QCOM_CLK_RCG2_CMD_ROOT_OFF)
enabled = false;
else
enabled = true;
/* mux settings */
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CFG_OFFSET(sc), &reg);
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
idx = (reg & QCOM_CLK_RCG2_CFG_SRC_SEL_MASK)
>> QCOM_CLK_RCG2_CFG_SRC_SEL_SHIFT;
DPRINTF(clknode_get_device(sc->clknode),
"%s: mux index %u, enabled=%d\n",
__func__, idx, enabled);
clknode_init_parent_idx(clk, idx);
/*
* If we could be sure our parent clocks existed here in the tree,
* we could calculate our current frequency by fetching the parent
* frequency and then do our divider math. Unfortunately that
* currently isn't the case.
*/
return(0);
}
static int
qcom_clk_rcg2_set_gate(struct clknode *clk, bool enable)
{
/*
* For now this isn't supported; there's some support for
* "shared" rcg2 nodes in the Qualcomm/upstream Linux trees but
* it's not currently needed for the supported platforms.
*/
return (0);
}
/*
* Program the parent index.
*
* This doesn't do the update. It also must be called with the device
* lock held.
*/
static void
qcom_clk_rcg2_set_parent_index_locked(struct qcom_clk_rcg2_sc *sc,
uint32_t index)
{
uint32_t reg;
CLKDEV_READ_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CFG_OFFSET(sc), &reg);
reg = reg & ~QCOM_CLK_RCG2_CFG_SRC_SEL_MASK;
reg = reg | (((index << QCOM_CLK_RCG2_CFG_SRC_SEL_SHIFT)
& QCOM_CLK_RCG2_CFG_SRC_SEL_MASK));
CLKDEV_WRITE_4(clknode_get_device(sc->clknode),
QCOM_CLK_RCG2_CFG_OFFSET(sc),
reg);
}
/*
* Set frequency
*
* fin - the parent frequency, if exists
* fout - starts as the requested frequency, ends with the configured
* or dry-run frequency
* Flags - CLK_SET_DRYRUN, CLK_SET_ROUND_UP, CLK_SET_ROUND_DOWN
* retval - 0, ERANGE
*/
static int
qcom_clk_rcg2_set_freq(struct clknode *clk, uint64_t fin, uint64_t *fout,
int flags, int *stop)
{
struct qcom_clk_rcg2_sc *sc;
const struct qcom_clk_freq_tbl *f;
const char **parent_names;
uint64_t p_freq, p_clk_freq;
int parent_cnt;
struct clknode *p_clk;
int i;
sc = clknode_get_softc(clk);
/*
* Find a suitable frequency in the frequency table.
*
* TODO: should pay attention to ROUND_UP / ROUND_DOWN and add
* a freqtbl method to handle both accordingly.
*/
f = qcom_clk_freq_tbl_lookup(sc->freq_tbl, *fout);
if (f == NULL) {
device_printf(clknode_get_device(sc->clknode),
"%s: no suitable freqtbl entry found for freq %llu\n",
__func__,
*fout);
return (ERANGE);
}
/*
* Find the parent index for the given parent clock.
* Abort if we can't actually find it.
*
* XXX TODO: this should be a clk API call!
*/
parent_cnt = clknode_get_parents_num(clk);
parent_names = clknode_get_parent_names(clk);
for (i = 0; i < parent_cnt; i++) {
if (parent_names[i] == NULL)
continue;
if (strcmp(parent_names[i], f->parent) == 0)
break;
}
if (i >= parent_cnt) {
device_printf(clknode_get_device(sc->clknode),
"%s: couldn't find suitable parent?\n",
__func__);
return (ENXIO);
}
/*
* If we aren't setting the parent clock, then we need
* to just program the new parent clock in and update.
* (or for DRYRUN just skip that and return the new
* frequency.)
*/
if ((sc->flags & QCOM_CLK_RCG2_FLAGS_SET_RATE_PARENT) == 0) {
if (flags & CLK_SET_DRYRUN) {
*fout = f->freq;
return (0);
}
if (sc->safe_pre_parent_idx > -1) {
DPRINTF(clknode_get_device(sc->clknode),
"%s: setting to safe parent idx %d\n",
__func__,
sc->safe_pre_parent_idx);
CLKDEV_DEVICE_LOCK(clknode_get_device(sc->clknode));
qcom_clk_rcg2_set_parent_index_locked(sc,
sc->safe_pre_parent_idx);
DPRINTF(clknode_get_device(sc->clknode),
"%s: safe parent: updating config\n", __func__);
if (! qcom_clk_rcg2_update_config_locked(sc)) {
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
DPRINTF(clknode_get_device(sc->clknode),
"%s: error updating config\n",
__func__);
return (ENXIO);
}
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
DPRINTF(clknode_get_device(sc->clknode),
"%s: safe parent: done\n", __func__);
clknode_set_parent_by_idx(sc->clknode,
sc->safe_pre_parent_idx);
}
/* Program parent index, then schedule update */
CLKDEV_DEVICE_LOCK(clknode_get_device(sc->clknode));
qcom_clk_rcg2_set_parent_index_locked(sc, i);
if (! qcom_clk_rcg2_update_config_locked(sc)) {
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
device_printf(clknode_get_device(sc->clknode),
"%s: couldn't program in parent idx %u!\n",
__func__, i);
return (ENXIO);
}
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
clknode_set_parent_by_idx(sc->clknode, i);
*fout = f->freq;
return (0);
}
/*
* If we /are/ setting the parent clock, then we need
* to determine what frequency we need the parent to
* be, and then reconfigure the parent to the new
* frequency, and then change our parent.
*
* (Again, if we're doing DRYRUN, just skip that
* and return the new frequency.)
*/
p_clk = clknode_find_by_name(f->parent);
if (p_clk == NULL) {
device_printf(clknode_get_device(sc->clknode),
"%s: couldn't find parent clk (%s)\n",
__func__, f->parent);
return (ENXIO);
}
/*
* Calculate required frequency from said parent clock to
* meet the needs of our target clock.
*/
p_freq = qcom_clk_rcg2_calc_input_freq(f->freq, f->m, f->n,
f->pre_div);
DPRINTF(clknode_get_device(sc->clknode),
"%s: request %llu, parent %s freq %llu, parent freq %llu\n",
__func__,
*fout,
f->parent,
f->freq,
p_freq);
/*
* To ensure glitch-free operation on some clocks, set it to
* a safe parent before programming our divisor and the parent
* clock configuration. Then once it's done, flip the parent
* to the new parent.
*
* If we're doing a dry-run then we don't need to re-parent the
* clock just yet!
*/
if (((flags & CLK_SET_DRYRUN) == 0) &&
(sc->safe_pre_parent_idx > -1)) {
DPRINTF(clknode_get_device(sc->clknode),
"%s: setting to safe parent idx %d\n",
__func__,
sc->safe_pre_parent_idx);
CLKDEV_DEVICE_LOCK(clknode_get_device(sc->clknode));
qcom_clk_rcg2_set_parent_index_locked(sc,
sc->safe_pre_parent_idx);
DPRINTF(clknode_get_device(sc->clknode),
"%s: safe parent: updating config\n", __func__);
if (! qcom_clk_rcg2_update_config_locked(sc)) {
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
DPRINTF(clknode_get_device(sc->clknode),
"%s: error updating config\n",
__func__);
return (ENXIO);
}
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
DPRINTF(clknode_get_device(sc->clknode),
"%s: safe parent: done\n", __func__);
clknode_set_parent_by_idx(sc->clknode,
sc->safe_pre_parent_idx);
}
/*
* Set the parent frequency before we change our mux and divisor
* configuration.
*/
if (clknode_get_freq(p_clk, &p_clk_freq) != 0) {
device_printf(clknode_get_device(sc->clknode),
"%s: couldn't get freq for parent clock %s\n",
__func__,
f->parent);
return (ENXIO);
}
if (p_clk_freq != p_freq) {
uint64_t n_freq;
int rv;
/*
* If we're doing a dryrun then call test_freq() not set_freq().
* That way we get the frequency back that we would be set to.
*
* If we're not doing a dry run then set the frequency, then
* call get_freq to get what it was set to.
*/
if (flags & CLK_SET_DRYRUN) {
n_freq = p_freq;
rv = clknode_test_freq(p_clk, n_freq, flags, 0,
&p_freq);
} else {
rv = clknode_set_freq(p_clk, p_freq, flags, 0);
}
if (rv != 0) {
device_printf(clknode_get_device(sc->clknode),
"%s: couldn't set parent clock %s frequency to "
"%llu\n",
__func__,
f->parent,
p_freq);
return (ENXIO);
}
/* Frequency was set, fetch what it was set to */
if ((flags & CLK_SET_DRYRUN) == 0) {
rv = clknode_get_freq(p_clk, &p_freq);
if (rv != 0) {
device_printf(clknode_get_device(sc->clknode),
"%s: couldn't get parent frequency",
__func__);
return (ENXIO);
}
}
}
DPRINTF(clknode_get_device(sc->clknode),
"%s: requested freq=%llu, target freq=%llu,"
" parent choice=%s, parent_freq=%llu\n",
__func__,
*fout,
f->freq,
f->parent,
p_freq);
/*
* Set the parent node, the parent programming and the divisor
* config. Because they're done together, we don't go via
* a mux method on this node.
*/
/*
* Program the divisor and parent.
*/
if ((flags & CLK_SET_DRYRUN) == 0) {
CLKDEV_DEVICE_LOCK(clknode_get_device(sc->clknode));
qcom_clk_rcg2_set_config_locked(sc, f, i);
if (! qcom_clk_rcg2_update_config_locked(sc)) {
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
device_printf(clknode_get_device(sc->clknode),
"%s: couldn't program in divisor, help!\n",
__func__);
return (ENXIO);
}
CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
clknode_set_parent_by_idx(sc->clknode, i);
}
/*
* p_freq is now the frequency that the parent /is/ set to.
* (Or would be set to for a dry run.)
*
* Calculate what the eventual frequency would be, we'll want
* this to return when we're done - and again, if it's a dryrun,
* don't set anything up. This doesn't rely on the register
* contents.
*/
*fout = qcom_clk_rcg2_calc_rate(p_freq, (f->n == 0 ? 0 : 1),
f->m, f->n, f->pre_div);
return (0);
}
static clknode_method_t qcom_clk_rcg2_methods[] = {
/* Device interface */
CLKNODEMETHOD(clknode_init, qcom_clk_rcg2_init),
CLKNODEMETHOD(clknode_recalc_freq, qcom_clk_rcg2_recalc),
CLKNODEMETHOD(clknode_set_gate, qcom_clk_rcg2_set_gate),
CLKNODEMETHOD(clknode_set_freq, qcom_clk_rcg2_set_freq),
CLKNODEMETHOD_END
};
DEFINE_CLASS_1(qcom_clk_fepll, qcom_clk_rcg2_class, qcom_clk_rcg2_methods,
sizeof(struct qcom_clk_rcg2_sc), clknode_class);
int
qcom_clk_rcg2_register(struct clkdom *clkdom,
struct qcom_clk_rcg2_def *clkdef)
{
struct clknode *clk;
struct qcom_clk_rcg2_sc *sc;
/*
* Right now the rcg2 code isn't supporting turning off the clock
* or limiting it to the lowest parent clock. But, do set the
* flags appropriately.
*/
if (clkdef->flags & QCOM_CLK_RCG2_FLAGS_CRITICAL)
clkdef->clkdef.flags |= CLK_NODE_CANNOT_STOP;
clk = clknode_create(clkdom, &qcom_clk_rcg2_class, &clkdef->clkdef);
if (clk == NULL)
return (1);
sc = clknode_get_softc(clk);
sc->clknode = clk;
sc->cmd_rcgr = clkdef->cmd_rcgr;
sc->hid_width = clkdef->hid_width;
sc->mnd_width = clkdef->mnd_width;
sc->safe_src_idx = clkdef->safe_src_idx;
sc->safe_pre_parent_idx = clkdef->safe_pre_parent_idx;
sc->cfg_offset = clkdef->cfg_offset;
sc->flags = clkdef->flags;
sc->freq_tbl = clkdef->freq_tbl;
clknode_register(clkdom, clk);
return (0);
}