diff mbox

[2/2,v2] cpufreq: qoriq: Don't look at clock implementation details

Message ID 1486532585-36463-2-git-send-email-yuantian.tang@nxp.com
State Not Applicable, archived
Headers show

Commit Message

tang yuantian Feb. 8, 2017, 5:43 a.m. UTC
From: Tang Yuantian <Yuantian.Tang@nxp.com>

Get the CPU clock's potential parent clocks from the clock interface
itself, rather than manually parsing the clocks property to find a
phandle, looking at the clock-names property of that, and assuming that
those are valid parent clocks for the cpu clock.

This is necessary now that the clocks are generated based on the clock
driver's knowledge of the chip rather than a fragile device-tree
description of the mux options.

We can now rely on the clock driver to ensure that the mux only exposes
options that are valid.  The cpufreq driver was currently being overly
conservative in some cases -- for example, the "min_cpufreq =
get_bus_freq()" restriction only applies to chips with erratum
A-004510, and whether the freq_mask used on p5020 is needed depends on
the actual frequencies of the PLLs (FWIW, p5040 has a similar
limitation but its .freq_mask was zero) -- and the frequency mask
mechanism made assumptions about particular parent clock indices that
are no longer valid.

Signed-off-by: Scott Wood <scottwood@nxp.com>
Signed-off-by: Tang Yuantian <yuantian.tang@nxp.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
---
v2:
  - added more soc compatible strings

 drivers/cpufreq/qoriq-cpufreq.c | 145 +++++++++++++---------------------------
 1 file changed, 48 insertions(+), 97 deletions(-)

Comments

kernel test robot Feb. 8, 2017, 11:19 a.m. UTC | #1
Hi Tang,

[auto build test WARNING on pm/linux-next]
[also build test WARNING on v4.10-rc7 next-20170208]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/yuantian-tang-nxp-com/cpufreq-qoriq-added-arm64-socs-support/20170208-163748
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: arm-multi_v7_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   drivers/cpufreq/qoriq-cpufreq.c: In function 'qoriq_cpufreq_cpu_init':
>> drivers/cpufreq/qoriq-cpufreq.c:230:2: warning: 'pnode' may be used uninitialized in this function [-Wmaybe-uninitialized]
     of_node_put(pnode);
     ^~~~~~~~~~~~~~~~~~

vim +/pnode +230 drivers/cpufreq/qoriq-cpufreq.c

defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  214  		pr_err("invalid frequency table: %d\n", ret);
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  215  		goto err_nomem1;
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  216  	}
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  217  
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  218  	data->table = table;
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  219  
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  220  	/* update ->cpus if we have cluster, no harm if not */
a4f20742 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2015-03-13  221  	set_affected_cpus(policy);
a4f20742 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2015-03-13  222  	policy->driver_data = data;
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  223  
906fe033 drivers/cpufreq/ppc-corenet-cpufreq.c Ed Swarthout  2014-06-05  224  	/* Minimum transition latency is 12 platform clocks */
906fe033 drivers/cpufreq/ppc-corenet-cpufreq.c Ed Swarthout  2014-06-05  225  	u64temp = 12ULL * NSEC_PER_SEC;
a4f20742 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2015-03-13  226  	do_div(u64temp, get_bus_freq());
906fe033 drivers/cpufreq/ppc-corenet-cpufreq.c Ed Swarthout  2014-06-05  227  	policy->cpuinfo.transition_latency = u64temp + 1;
6712d293 drivers/cpufreq/ppc-corenet-cpufreq.c Tim Gardner   2014-04-28  228  
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  229  	of_node_put(np);
8a95c144 drivers/cpufreq/qoriq-cpufreq.c       Tang Yuantian 2015-06-04 @230  	of_node_put(pnode);
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  231  
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  232  	return 0;
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  233  
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  234  err_nomem1:
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  235  	kfree(table);
8a95c144 drivers/cpufreq/qoriq-cpufreq.c       Tang Yuantian 2015-06-04  236  err_pclk:
8a95c144 drivers/cpufreq/qoriq-cpufreq.c       Tang Yuantian 2015-06-04  237  	kfree(data->pclk);
defa4c73 drivers/cpufreq/ppc-corenet-cpufreq.c Tang Yuantian 2013-06-05  238  err_nomem2:

:::::: The code at line 230 was first introduced by commit
:::::: 8a95c1441c799bb0f0d31cdb11523d91923d51a7 cpufreq: qoriq: optimize the CPU frequency switching time

:::::: TO: Tang Yuantian <Yuantian.Tang@freescale.com>
:::::: CC: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox

Patch

diff --git a/drivers/cpufreq/qoriq-cpufreq.c b/drivers/cpufreq/qoriq-cpufreq.c
index 53d8c3f..eee83c1 100644
--- a/drivers/cpufreq/qoriq-cpufreq.c
+++ b/drivers/cpufreq/qoriq-cpufreq.c
@@ -11,6 +11,7 @@ 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
 
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/cpufreq.h>
 #include <linux/cpu_cooling.h>
 #include <linux/errno.h>
@@ -37,53 +38,20 @@  struct cpu_data {
 	struct thermal_cooling_device *cdev;
 };
 
+/*
+ * Don't use cpufreq on this SoC -- used when the SoC would have otherwise
+ * matched a more generic compatible.
+ */
+#define SOC_BLACKLIST		1
+
 /**
  * struct soc_data - SoC specific data
- * @freq_mask: mask the disallowed frequencies
- * @flag: unique flags
+ * @flags: SOC_xxx
  */
 struct soc_data {
-	u32 freq_mask[4];
-	u32 flag;
-};
-
-#define FREQ_MASK	1
-/* see hardware specification for the allowed frqeuencies */
-static const struct soc_data sdata[] = {
-	{ /* used by p2041 and p3041 */
-		.freq_mask = {0x8, 0x8, 0x2, 0x2},
-		.flag = FREQ_MASK,
-	},
-	{ /* used by p5020 */
-		.freq_mask = {0x8, 0x2},
-		.flag = FREQ_MASK,
-	},
-	{ /* used by p4080, p5040 */
-		.freq_mask = {0},
-		.flag = 0,
-	},
+	u32 flags;
 };
 
-/*
- * the minimum allowed core frequency, in Hz
- * for chassis v1.0, >= platform frequency
- * for chassis v2.0, >= platform frequency / 2
- */
-static u32 min_cpufreq;
-static const u32 *fmask;
-
-#if defined(CONFIG_ARM)
-static int get_cpu_physical_id(int cpu)
-{
-	return topology_core_id(cpu);
-}
-#else
-static int get_cpu_physical_id(int cpu)
-{
-	return get_hard_smp_processor_id(cpu);
-}
-#endif
-
 static u32 get_bus_freq(void)
 {
 	struct device_node *soc;
@@ -101,9 +69,10 @@  static u32 get_bus_freq(void)
 	return sysfreq;
 }
 
-static struct device_node *cpu_to_clk_node(int cpu)
+static struct clk *cpu_to_clk(int cpu)
 {
-	struct device_node *np, *clk_np;
+	struct device_node *np;
+	struct clk *clk;
 
 	if (!cpu_present(cpu))
 		return NULL;
@@ -112,37 +81,28 @@  static struct device_node *cpu_to_clk_node(int cpu)
 	if (!np)
 		return NULL;
 
-	clk_np = of_parse_phandle(np, "clocks", 0);
-	if (!clk_np)
-		return NULL;
-
+	clk = of_clk_get(np, 0);
 	of_node_put(np);
-
-	return clk_np;
+	return clk;
 }
 
 /* traverse cpu nodes to get cpu mask of sharing clock wire */
 static void set_affected_cpus(struct cpufreq_policy *policy)
 {
-	struct device_node *np, *clk_np;
 	struct cpumask *dstp = policy->cpus;
+	struct clk *clk;
 	int i;
 
-	np = cpu_to_clk_node(policy->cpu);
-	if (!np)
-		return;
-
 	for_each_present_cpu(i) {
-		clk_np = cpu_to_clk_node(i);
-		if (!clk_np)
+		clk = cpu_to_clk(i);
+		if (IS_ERR(clk)) {
+			pr_err("%s: no clock for cpu %d\n", __func__, i);
 			continue;
+		}
 
-		if (clk_np == np)
+		if (clk_is_match(policy->clk, clk))
 			cpumask_set_cpu(i, dstp);
-
-		of_node_put(clk_np);
 	}
-	of_node_put(np);
 }
 
 /* reduce the duplicated frequencies in frequency table */
@@ -200,8 +160,9 @@  static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	struct device_node *np, *pnode;
 	int i, count, ret;
-	u32 freq, mask;
+	u32 freq;
 	struct clk *clk;
+	const struct clk_hw *hwclk;
 	struct cpufreq_frequency_table *table;
 	struct cpu_data *data;
 	unsigned int cpu = policy->cpu;
@@ -221,17 +182,13 @@  static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		goto err_nomem2;
 	}
 
-	pnode = of_parse_phandle(np, "clocks", 0);
-	if (!pnode) {
-		pr_err("%s: could not get clock information\n", __func__);
-		goto err_nomem2;
-	}
+	hwclk = __clk_get_hw(policy->clk);
+	count = clk_hw_get_num_parents(hwclk);
 
-	count = of_property_count_strings(pnode, "clock-names");
 	data->pclk = kcalloc(count, sizeof(struct clk *), GFP_KERNEL);
 	if (!data->pclk) {
 		pr_err("%s: no memory\n", __func__);
-		goto err_node;
+		goto err_nomem2;
 	}
 
 	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
@@ -240,23 +197,11 @@  static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		goto err_pclk;
 	}
 
-	if (fmask)
-		mask = fmask[get_cpu_physical_id(cpu)];
-	else
-		mask = 0x0;
-
 	for (i = 0; i < count; i++) {
-		clk = of_clk_get(pnode, i);
+		clk = clk_hw_get_parent_by_index(hwclk, i)->clk;
 		data->pclk[i] = clk;
 		freq = clk_get_rate(clk);
-		/*
-		 * the clock is valid if its frequency is not masked
-		 * and large than minimum allowed frequency.
-		 */
-		if (freq < min_cpufreq || (mask & (1 << i)))
-			table[i].frequency = CPUFREQ_ENTRY_INVALID;
-		else
-			table[i].frequency = freq / 1000;
+		table[i].frequency = freq / 1000;
 		table[i].driver_data = i;
 	}
 	freq_table_redup(table, count);
@@ -290,10 +235,7 @@  static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	kfree(table);
 err_pclk:
 	kfree(data->pclk);
-err_node:
-	of_node_put(pnode);
 err_nomem2:
-	policy->driver_data = NULL;
 	kfree(data);
 err_np:
 	of_node_put(np);
@@ -357,12 +299,25 @@  static struct cpufreq_driver qoriq_cpufreq_driver = {
 	.attr		= cpufreq_generic_attr,
 };
 
+static const struct soc_data blacklist = {
+	.flags = SOC_BLACKLIST,
+};
+
 static const struct of_device_id node_matches[] __initconst = {
-	{ .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
-	{ .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
-	{ .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
-	{ .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
-	{ .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
+	/* e6500 cannot use cpufreq due to erratum A-008083 */
+	{ .compatible = "fsl,b4420-clockgen", &blacklist },
+	{ .compatible = "fsl,b4860-clockgen", &blacklist },
+	{ .compatible = "fsl,t2080-clockgen", &blacklist },
+	{ .compatible = "fsl,t4240-clockgen", &blacklist },
+
+	{ .compatible = "fsl,ls1012a-clockgen", },
+	{ .compatible = "fsl,ls1021a-clockgen", },
+	{ .compatible = "fsl,ls1043a-clockgen", },
+	{ .compatible = "fsl,ls1046a-clockgen", },
+	{ .compatible = "fsl,ls1088a-clockgen", },
+	{ .compatible = "fsl,ls2080a-clockgen", },
+	{ .compatible = "fsl,p4080-clockgen", },
+	{ .compatible = "fsl,qoriq-clockgen-1.0", },
 	{ .compatible = "fsl,qoriq-clockgen-2.0", },
 	{}
 };
@@ -380,16 +335,12 @@  static int __init qoriq_cpufreq_init(void)
 
 	match = of_match_node(node_matches, np);
 	data = match->data;
-	if (data) {
-		if (data->flag)
-			fmask = data->freq_mask;
-		min_cpufreq = get_bus_freq();
-	} else {
-		min_cpufreq = get_bus_freq() / 2;
-	}
 
 	of_node_put(np);
 
+	if (data && data->flags & SOC_BLACKLIST)
+		return -ENODEV;
+
 	ret = cpufreq_register_driver(&qoriq_cpufreq_driver);
 	if (!ret)
 		pr_info("Freescale QorIQ CPU frequency scaling driver\n");