The root clock generators with MND divider has the capability to support
change in duty-cycle by updating the 'D'. Add the clock ops which would
check all the boundary conditions and enable setting the desired duty-cycle
as per the consumer.
Signed-off-by: Taniya Das <[email protected]>
---
drivers/clk/qcom/clk-rcg2.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index 42f13a2..e070f1a 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -357,6 +357,44 @@ static int clk_rcg2_set_floor_rate_and_parent(struct clk_hw *hw,
return __clk_rcg2_set_rate(hw, rate, FLOOR);
}
+static int clk_rcg2_set_duty_cycle(struct clk_hw *hw, struct clk_duty *duty)
+{
+ struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+ u32 notn_m_val, n_val, m_val, d_val, not2d_val, mask, duty_per;
+ int ret;
+
+ if (!rcg->mnd_width)
+ return 0;
+
+ mask = BIT(rcg->mnd_width) - 1;
+
+ regmap_read(rcg->clkr.regmap, RCG_N_OFFSET(rcg), ¬n_m_val);
+ regmap_read(rcg->clkr.regmap, RCG_M_OFFSET(rcg), &m_val);
+
+ n_val = (~(notn_m_val) + m_val) & mask;
+
+ /* Calculate 2d value */
+ d_val = DIV_ROUND_CLOSEST(n_val * duty_per * 2, 100);
+
+ /* Check BIT WIDTHS OF 2d. If D is too big reduce Duty cycle. */
+ if (d_val > mask)
+ d_val = mask;
+
+ if ((d_val / 2) > (n_val - m_val))
+ d_val = (n_val - m_val) * 2;
+ else if ((d_val / 2) < (m_val / 2))
+ d_val = m_val;
+
+ not2d_val = ~d_val & mask;
+
+ ret = regmap_update_bits(rcg->clkr.regmap, RCG_D_OFFSET(rcg), mask,
+ not2d_val);
+ if (ret)
+ return ret;
+
+ return update_config(rcg);
+}
+
const struct clk_ops clk_rcg2_ops = {
.is_enabled = clk_rcg2_is_enabled,
.get_parent = clk_rcg2_get_parent,
@@ -365,6 +403,7 @@ const struct clk_ops clk_rcg2_ops = {
.determine_rate = clk_rcg2_determine_rate,
.set_rate = clk_rcg2_set_rate,
.set_rate_and_parent = clk_rcg2_set_rate_and_parent,
+ .set_duty_cycle = clk_rcg2_set_duty_cycle,
};
EXPORT_SYMBOL_GPL(clk_rcg2_ops);
@@ -376,6 +415,7 @@ const struct clk_ops clk_rcg2_floor_ops = {
.determine_rate = clk_rcg2_determine_floor_rate,
.set_rate = clk_rcg2_set_floor_rate,
.set_rate_and_parent = clk_rcg2_set_floor_rate_and_parent,
+ .set_duty_cycle = clk_rcg2_set_duty_cycle,
};
EXPORT_SYMBOL_GPL(clk_rcg2_floor_ops);
--
Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc.is a member
of the Code Aurora Forum, hosted by the Linux Foundation.
Hi Taniya,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on clk/clk-next]
[also build test WARNING on v5.12-rc2 next-20210310]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Taniya-Das/clk-qcom-clk-rcg2-Add-support-for-duty-cycle-for-RCG/20210311-024657
base: https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git clk-next
config: powerpc64-randconfig-r035-20210310 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project cd9a69289c7825d54450cb6829fef2c8e0f1963a)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install powerpc64 cross compiling tool for clang build
# apt-get install binutils-powerpc64-linux-gnu
# https://github.com/0day-ci/linux/commit/affeb4ce842dbf391537c4e7279ff85e050e1e47
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Taniya-Das/clk-qcom-clk-rcg2-Add-support-for-duty-cycle-for-RCG/20210311-024657
git checkout affeb4ce842dbf391537c4e7279ff85e050e1e47
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
>> drivers/clk/qcom/clk-rcg2.c:377:36: warning: variable 'duty_per' is uninitialized when used here [-Wuninitialized]
d_val = DIV_ROUND_CLOSEST(n_val * duty_per * 2, 100);
^~~~~~~~
include/linux/math.h:87:18: note: expanded from macro 'DIV_ROUND_CLOSEST'
typeof(x) __x = x; \
^
drivers/clk/qcom/clk-rcg2.c:363:64: note: initialize the variable 'duty_per' to silence this warning
u32 notn_m_val, n_val, m_val, d_val, not2d_val, mask, duty_per;
^
= 0
1 warning generated.
vim +/duty_per +377 drivers/clk/qcom/clk-rcg2.c
359
360 static int clk_rcg2_set_duty_cycle(struct clk_hw *hw, struct clk_duty *duty)
361 {
362 struct clk_rcg2 *rcg = to_clk_rcg2(hw);
363 u32 notn_m_val, n_val, m_val, d_val, not2d_val, mask, duty_per;
364 int ret;
365
366 if (!rcg->mnd_width)
367 return 0;
368
369 mask = BIT(rcg->mnd_width) - 1;
370
371 regmap_read(rcg->clkr.regmap, RCG_N_OFFSET(rcg), ¬n_m_val);
372 regmap_read(rcg->clkr.regmap, RCG_M_OFFSET(rcg), &m_val);
373
374 n_val = (~(notn_m_val) + m_val) & mask;
375
376 /* Calculate 2d value */
> 377 d_val = DIV_ROUND_CLOSEST(n_val * duty_per * 2, 100);
378
379 /* Check BIT WIDTHS OF 2d. If D is too big reduce Duty cycle. */
380 if (d_val > mask)
381 d_val = mask;
382
383 if ((d_val / 2) > (n_val - m_val))
384 d_val = (n_val - m_val) * 2;
385 else if ((d_val / 2) < (m_val / 2))
386 d_val = m_val;
387
388 not2d_val = ~d_val & mask;
389
390 ret = regmap_update_bits(rcg->clkr.regmap, RCG_D_OFFSET(rcg), mask,
391 not2d_val);
392 if (ret)
393 return ret;
394
395 return update_config(rcg);
396 }
397
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]