[3/3] ASoC: fsl_ssi: remove register defaults

Commit Message

Maciej S. Szmigiero Jan. 17, 2016, 10:02 p.m. UTC

On 17.01.2016 19:38, Timur Tabi wrote:
> Maciej S. Szmigiero wrote:
>> On 17.01.2016 15:16, Maciej S. Szmigiero wrote:
>>> On 17.01.2016 06:16, Timur Tabi wrote:
>>>> Maciej S. Szmigiero wrote:
>>>>> This is because (at least according to the datasheet) imx21-class SSI
>>>>> registers end at CCSR_SSI_SRMSK (no SACC{ST,EN,DIS} regs), so
>>>>> reading them for cache initialization may not be safe.
>>>>>
>>>>> Also, a "MXC 91221 only" comment before these regs in FSL tree
>>>>> (drivers/mxc/ssi/registers.h) seems to confirm that these registers
>>>>> aren't present at least on some SSI (or SoC) models.
>>>>
>>>> Can't we just mark them as precious or something, so that we don't have to have two structures?
>>>
>>> Looks like it can be done with just one static regmap config struct
>>> used then as template - I will post updated patch.

Patch updated according to Timur's suggestions (needs regmap fix):


> However, I wonder if this patch is necessary at all.
> If the regs don't exist on an i.MX 21, does it really matter if we write to them?

At least i.MX6 datasheet SSI description has the following information:
"Transfer bus errors are generated upon response to the following:
* Write transfer to a read-only register.
* Read or write access to a register space beyond the last populated register of the SSI
in its memory map (up until the end of the allocated memory address range of the
SSI)."

Maciej Szmigiero

Comments

Fabio Estevam Jan. 18, 2016, 12:51 p.m. UTC | #1

Hi Maciej,

On Sun, Jan 17, 2016 at 8:02 PM, Maciej S. Szmigiero
<[e-mail]> wrote:

> Patch updated according to Timur's suggestions (needs regmap fix):
> diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c

Tested your patch against linux-next and it did not give me any warnings:

Tested-by: Fabio Estevam <[e-mail]>

Maciej S. Szmigiero Jan. 18, 2016, 7:08 p.m. UTC | #2

Hi Fabio,

On 18.01.2016 13:51, Fabio Estevam wrote:
> Hi Maciej,
> 
> On Sun, Jan 17, 2016 at 8:02 PM, Maciej S. Szmigiero
> <[e-mail]> wrote:
> 
>> Patch updated according to Timur's suggestions (needs regmap fix):
>> diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
> 
> Tested your patch against linux-next and it did not give me any warnings:
> 
> Tested-by: Fabio Estevam <[e-mail]>

Thanks for testing, I have submitted this version now.

Maciej

Patch

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 40dfd8a36484..ed8de1035cda 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -112,20 +112,6 @@  struct fsl_ssi_rxtx_reg_val {
 	struct fsl_ssi_reg_val tx;
 };
 
-static const struct reg_default fsl_ssi_reg_defaults[] = {
-	{CCSR_SSI_SCR,     0x00000000},
-	{CCSR_SSI_SIER,    0x00003003},
-	{CCSR_SSI_STCR,    0x00000200},
-	{CCSR_SSI_SRCR,    0x00000200},
-	{CCSR_SSI_STCCR,   0x00040000},
-	{CCSR_SSI_SRCCR,   0x00040000},
-	{CCSR_SSI_SACNT,   0x00000000},
-	{CCSR_SSI_STMSK,   0x00000000},
-	{CCSR_SSI_SRMSK,   0x00000000},
-	{CCSR_SSI_SACCEN,  0x00000000},
-	{CCSR_SSI_SACCDIS, 0x00000000},
-};
-
 static bool fsl_ssi_readable_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
@@ -190,8 +176,7 @@  static const struct regmap_config fsl_ssi_regconfig = {
 	.val_bits = 32,
 	.reg_stride = 4,
 	.val_format_endian = REGMAP_ENDIAN_NATIVE,
-	.reg_defaults = fsl_ssi_reg_defaults,
-	.num_reg_defaults = ARRAY_SIZE(fsl_ssi_reg_defaults),
+	.num_reg_defaults_raw = CCSR_SSI_SACCDIS / sizeof(uint32_t) + 1,
 	.readable_reg = fsl_ssi_readable_reg,
 	.volatile_reg = fsl_ssi_volatile_reg,
 	.precious_reg = fsl_ssi_precious_reg,
@@ -201,6 +186,7 @@  static const struct regmap_config fsl_ssi_regconfig = {
 
 struct fsl_ssi_soc_data {
 	bool imx;
+	bool imx21regs; /* imx21-class SSI - no SACC{ST,EN,DIS} regs */
 	bool offline_config;
 	u32 sisr_write_mask;
 };
@@ -303,6 +289,7 @@  static struct fsl_ssi_soc_data fsl_ssi_mpc8610 = {
 
 static struct fsl_ssi_soc_data fsl_ssi_imx21 = {
 	.imx = true,
+	.imx21regs = true,
 	.offline_config = true,
 	.sisr_write_mask = 0,
 };
@@ -586,8 +573,12 @@  static void fsl_ssi_setup_ac97(struct fsl_ssi_private *ssi_private)
 	 */
 	regmap_write(regs, CCSR_SSI_SACNT,
 			CCSR_SSI_SACNT_AC97EN | CCSR_SSI_SACNT_FV);
-	regmap_write(regs, CCSR_SSI_SACCDIS, 0xff);
-	regmap_write(regs, CCSR_SSI_SACCEN, 0x300);
+
+	/* no SACC{ST,EN,DIS} regs on imx21-class SSI */
+	if (!ssi_private->soc->imx21regs) {
+		regmap_write(regs, CCSR_SSI_SACCDIS, 0xff);
+		regmap_write(regs, CCSR_SSI_SACCEN, 0x300);
+	}
 
 	/*
 	 * Enable SSI, Transmit and Receive. AC97 has to communicate with the
@@ -1397,6 +1388,7 @@  static int fsl_ssi_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *iomem;
 	char name[64];
+	struct regmap_config regconfig = fsl_ssi_regconfig;
 
 	of_id = of_match_device(fsl_ssi_ids, &pdev->dev);
 	if (!of_id || !of_id->data)
@@ -1444,15 +1436,25 @@  static int fsl_ssi_probe(struct platform_device *pdev)
 		return PTR_ERR(iomem);
 	ssi_private->ssi_phys = res->start;
 
+	if (ssi_private->soc->imx21regs) {
+		/*
+		 * According to datasheet imx21-class SSI
+		 * don't have SACC{ST,EN,DIS} regs.
+		 */
+		regconfig.max_register = CCSR_SSI_SRMSK;
+		regconfig.num_reg_defaults_raw =
+			CCSR_SSI_SRMSK / sizeof(uint32_t) + 1;
+	}
+
 	ret = of_property_match_string(np, "clock-names", "ipg");
 	if (ret < 0) {
 		ssi_private->has_ipg_clk_name = false;
 		ssi_private->regs = devm_regmap_init_mmio(&pdev->dev, iomem,
-			&fsl_ssi_regconfig);
+			&regconfig);
 	} else {
 		ssi_private->has_ipg_clk_name = true;
 		ssi_private->regs = devm_regmap_init_mmio_clk(&pdev->dev,
-			"ipg", iomem, &fsl_ssi_regconfig);
+			"ipg", iomem, &regconfig);
 	}
 	if (IS_ERR(ssi_private->regs)) {
 		dev_err(&pdev->dev, "Failed to init register map\n");