Re: [PATCH 02/16] OMAP3: PM: Create list to keep track of various smartreflex instances.

[Kevin Hilman <khilman@deeprootsystems.com>]

Mike Turquette <mturquette@ti.com> writes:

> Gopinath, Thara wrote:
>> This patch removes the pointer sr1, sr2 in smartreflex.c and
>> instead creatse a list for keeping track of multiple smartreflex
>> instances.. This makes it scalable for next gen OMAPs where there
>> are more than two smartreflex modules.
>>
>> Signed-off-by: Thara Gopinath <thara@ti.com>
>> ---
>>  arch/arm/mach-omap2/smartreflex.c |  114 ++++++++++++++++++++++++------------
>>  1 files changed, 76 insertions(+), 38 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/smartreflex.c b/arch/arm/mach-omap2/smartreflex.c
>> index 1c5ec37..4a9c2e2 100644
>> --- a/arch/arm/mach-omap2/smartreflex.c
>> +++ b/arch/arm/mach-omap2/smartreflex.c
>> @@ -26,6 +26,7 @@
>>  #include <linux/kobject.h>
>>  #include <linux/i2c/twl.h>
>>  #include <linux/io.h>
>> +#include <linux/list.h>
>>   #include <plat/omap34xx.h>
>>  #include <plat/control.h>
>> @@ -51,9 +52,12 @@ struct omap_sr {
>>  	u32		opp5_nvalue;
>>  	u32		senp_mod, senn_mod;
>>  	void __iomem	*srbase_addr;
>> -	void __iomem	*vpbase_addr;
>> +	struct list_head 	node;
>>  };
>>  +/* sr_list contains all the instances of smartreflex module */
>> +static LIST_HEAD(sr_list);
>> +
>>  #define SR_REGADDR(offs)	(sr->srbase_addr + offset)
>>   static inline void sr_write_reg(struct omap_sr *sr, unsigned
>> offset, u32 value)
>> @@ -78,6 +82,20 @@ static inline u32 sr_read_reg(struct omap_sr *sr, unsigned offset)
>>  	return __raw_readl(SR_REGADDR(offset));
>>  }
>>  +static struct omap_sr *_sr_lookup(int srid)
>> +{
>> +	struct omap_sr *sr_info, *temp_sr_info;
>> +
>> +	sr_info = NULL;
>> +	list_for_each_entry(temp_sr_info, &sr_list, node) {
>> +		if (srid == temp_sr_info->srid) {
>> +			sr_info = temp_sr_info;
>> +			break;
>> +		}
>> +	}
>> +	return sr_info;
>> +}
>> +
>>  static int sr_clk_enable(struct omap_sr *sr)
>>  {
>>  	if (clk_enable(sr->clk) != 0) {
>> @@ -151,11 +169,17 @@ static u8 get_vdd1_opp(void)
>>  {
>>  	struct omap_opp *opp;
>>  	unsigned long freq;
>> +	struct omap_sr *sr_info = _sr_lookup(SR1);
>
> Why has the list implementation been chosen over individually
> registered platform devices?  

Not sure I follow your question exactly here, but IIUC, Thara converts
to individually registered platform_devices in the next patch.  This
is a preliminary one to prepare for that.  In PATCH 03/16, the devices
are found via hwmod then registered via omap_device_build() (which in
turn does the platform_device_register())

Kevin


> There seems to be a trend lately in
> device drivers to have a single platform device with either an array
> of pointers or a list implementation to track the multiple instances
> of the same device on a board.  McBSP is another example of this
> approach.
>
> Why is that?  Is it a bad idea to have each SR instance be a separate
> platform device?  Please let me know if my question is nuts.
>
> Mike
>
>>  -	if (sr1.vdd_opp_clk == NULL || IS_ERR(sr1.vdd_opp_clk))
>> +	if (!sr_info) {
>> +		pr_warning("omap_sr struct corresponding to SR1 not found\n");
>> +		return 0;
>> +	}
>> +
>> +	if (sr_info->vdd_opp_clk == NULL || IS_ERR(sr_info->vdd_opp_clk))
>>  		return 0;
>>  -	freq = sr1.vdd_opp_clk->rate;
>> +	freq = sr_info->vdd_opp_clk->rate;
>>  	opp = opp_find_freq_ceil(OPP_MPU, &freq);
>>  	if (IS_ERR(opp))
>>  		return 0;
>> @@ -163,9 +187,9 @@ static u8 get_vdd1_opp(void)
>>  	 * Use higher freq voltage even if an exact match is not available
>>  	 * we are probably masking a clock framework bug, so warn
>>  	 */
>> -	if (unlikely(freq != sr1.vdd_opp_clk->rate))
>> +	if (unlikely(freq != sr_info->vdd_opp_clk->rate))
>>  		pr_warning("%s: Available freq %ld != dpll freq %ld.\n",
>> -			   __func__, freq, sr1.vdd_opp_clk->rate);
>> +			   __func__, freq, sr_info->vdd_opp_clk->rate);
>>   	return opp_get_opp_id(opp);
>>  }
>> @@ -174,11 +198,17 @@ static u8 get_vdd2_opp(void)
>>  {
>>  	struct omap_opp *opp;
>>  	unsigned long freq;
>> +	struct omap_sr *sr_info = _sr_lookup(SR2);
>> +
>> +	if (!sr_info) {
>> +		pr_warning("omap_sr struct corresponding to SR2 not found\n");
>> +		return 0;
>> +	}
>>  -	if (sr2.vdd_opp_clk == NULL || IS_ERR(sr2.vdd_opp_clk))
>> +	if (sr_info->vdd_opp_clk == NULL || IS_ERR(sr_info->vdd_opp_clk))
>>  		return 0;
>>  -	freq = sr2.vdd_opp_clk->rate;
>> +	freq = sr_info->vdd_opp_clk->rate;
>>  	opp = opp_find_freq_ceil(OPP_L3, &freq);
>>  	if (IS_ERR(opp))
>>  		return 0;
>> @@ -187,9 +217,9 @@ static u8 get_vdd2_opp(void)
>>  	 * Use higher freq voltage even if an exact match is not available
>>  	 * we are probably masking a clock framework bug, so warn
>>  	 */
>> -	if (unlikely(freq != sr2.vdd_opp_clk->rate))
>> +	if (unlikely(freq != sr_info->vdd_opp_clk->rate))
>>  		pr_warning("%s: Available freq %ld != dpll freq %ld.\n",
>> -			   __func__, freq, sr2.vdd_opp_clk->rate);
>> +			   __func__, freq, sr_info->vdd_opp_clk->rate);
>>  	return opp_get_opp_id(opp);
>>  }
>>  @@ -694,14 +724,13 @@ static void sr_disable(struct omap_sr *sr)
>>   void sr_start_vddautocomap(int srid, u32 target_opp_no)
>>  {
>> -	struct omap_sr *sr = NULL;
>> +	struct omap_sr *sr = _sr_lookup(srid);
>>  -	if (srid == SR1)
>> -		sr = &sr1;
>> -	else if (srid == SR2)
>> -		sr = &sr2;
>> -	else
>> +	if (!sr) {
>> +		pr_warning("omap_sr struct corresponding to SR%d not found\n",
>> +								srid);
>>  		return;
>> +	}
>>   	if (sr->is_sr_reset == 1) {
>>  		sr_clk_enable(sr);
>> @@ -719,14 +748,13 @@ EXPORT_SYMBOL(sr_start_vddautocomap);
>>   int sr_stop_vddautocomap(int srid)
>>  {
>> -	struct omap_sr *sr = NULL;
>> +	struct omap_sr *sr = _sr_lookup(srid);
>>  -	if (srid == SR1)
>> -		sr = &sr1;
>> -	else if (srid == SR2)
>> -		sr = &sr2;
>> -	else
>> -		return -EINVAL;
>> +	if (!sr) {
>> +		pr_warning("omap_sr struct corresponding to SR%d not found\n",
>> +								srid);
>> +		return false;
>> +	}
>>   	if (sr->is_autocomp_active == 1) {
>>  		sr_disable(sr);
>> @@ -744,14 +772,13 @@ EXPORT_SYMBOL(sr_stop_vddautocomap);
>>  void enable_smartreflex(int srid)
>>  {
>>  	u32 target_opp_no = 0;
>> -	struct omap_sr *sr = NULL;
>> +	struct omap_sr *sr = _sr_lookup(srid);
>>  -	if (srid == SR1)
>> -		sr = &sr1;
>> -	else if (srid == SR2)
>> -		sr = &sr2;
>> -	else
>> +	if (!sr) {
>> +		pr_warning("omap_sr struct corresponding to SR%d not found\n",
>> +								srid);
>>  		return;
>> +	}
>>   	if (sr->is_autocomp_active == 1) {
>>  		if (sr->is_sr_reset == 1) {
>> @@ -779,15 +806,13 @@ void enable_smartreflex(int srid)
>>  void disable_smartreflex(int srid)
>>  {
>>  	u32 i = 0;
>> +	struct omap_sr *sr = _sr_lookup(srid);
>>  -	struct omap_sr *sr = NULL;
>> -
>> -	if (srid == SR1)
>> -		sr = &sr1;
>> -	else if (srid == SR2)
>> -		sr = &sr2;
>> -	else
>> +	if (!sr) {
>> +		pr_warning("omap_sr struct corresponding to SR%d not found\n",
>> +								srid);
>>  		return;
>> +	}
>>   	if (sr->is_autocomp_active == 1) {
>>  		if (sr->is_sr_reset == 0) {
>> @@ -920,7 +945,13 @@ int sr_voltagescale_vcbypass(u32 target_opp, u32 current_opp,
>>  static ssize_t omap_sr_vdd1_autocomp_show(struct kobject *kobj,
>>  					struct kobj_attribute *attr, char *buf)
>>  {
>> -	return sprintf(buf, "%d\n", sr1.is_autocomp_active);
>> +	struct omap_sr *sr_info = _sr_lookup(SR1);
>> +
>> +	if (!sr_info) {
>> +		pr_warning("omap_sr struct corresponding to SR1 not found\n");
>> +		return 0;
>> +	}
>> +	return sprintf(buf, "%d\n", sr_info->is_autocomp_active);
>>  }
>>   static ssize_t omap_sr_vdd1_autocomp_store(struct kobject *kobj,
>> @@ -960,7 +991,13 @@ static struct kobj_attribute sr_vdd1_autocomp = {
>>  static ssize_t omap_sr_vdd2_autocomp_show(struct kobject *kobj,
>>  					struct kobj_attribute *attr, char *buf)
>>  {
>> -	return sprintf(buf, "%d\n", sr2.is_autocomp_active);
>> +	struct omap_sr *sr_info = _sr_lookup(SR2);
>> +
>> +	if (!sr_info) {
>> +		pr_warning("omap_sr struct corresponding to SR2 not found\n");
>> +		return 0;
>> +	}
>> +	return sprintf(buf, "%d\n", sr_info->is_autocomp_active);
>>  }
>>   static ssize_t omap_sr_vdd2_autocomp_store(struct kobject *kobj,
>> @@ -1010,7 +1047,6 @@ static int __init omap3_sr_init(void)
>>  	RdReg |= DCDC_GLOBAL_CFG_ENABLE_SRFLX;
>>  	ret |= twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, RdReg,
>>  				R_DCDC_GLOBAL_CFG);
>> -
>>  	if (cpu_is_omap34xx()) {
>>  		sr1.clk = clk_get(NULL, "sr1_fck");
>>  		sr2.clk = clk_get(NULL, "sr2_fck");
>> @@ -1036,6 +1072,8 @@ static int __init omap3_sr_init(void)
>>  	ret = sysfs_create_file(power_kobj, &sr_vdd2_autocomp.attr);
>>  	if (ret)
>>  		pr_err("sysfs_create_file failed: %d\n", ret);
>> +	list_add(&sr1.node, &sr_list);
>> +	list_add(&sr2.node, &sr_list);
>>   	return 0;
>>  }