ASoC: Intel: sst: Delete sst_shim_regs64; saved regs are never used

In commit 9a075265c6 ("ASoC: Intel: sst: Remove unused function
sst_restore_shim64()"), we deleted the sst_restore_shim64() since it
was never used.  ...but a quick look at the code shows that we should
also be able to remove the sst_save_shim64() function and the
structure members we were storing data in.

Once we delete sst_save_shim64() there are no longer any users of the
'sst_shim_regs64' structure.  That means we can delete it completely
and also avoid allocating memory for it.  This saves a whopping 136
bytes of devm allocated memory.  We also get the nice benefit of
avoiding an error path in the init code.

Note that the saving code that we're removing (and the comments
talking about how important it is to do the save) has been around
since commit 336cfbb05e ("ASoC: Intel: mrfld- add ACPI module").

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/atom/sst/sst.c

@@ -382,21 +382,6 @@ void sst_context_cleanup(struct intel_sst_drv *ctx)
 }
 EXPORT_SYMBOL_GPL(sst_context_cleanup);
 
-static inline void sst_save_shim64(struct intel_sst_drv *ctx,
-			    void __iomem *shim,
-			    struct sst_shim_regs64 *shim_regs)
-{
-	unsigned long irq_flags;
-
-	spin_lock_irqsave(&ctx->ipc_spin_lock, irq_flags);
-
-	shim_regs->imrx = sst_shim_read64(shim, SST_IMRX);
-	shim_regs->csr = sst_shim_read64(shim, SST_CSR);
-
-
-	spin_unlock_irqrestore(&ctx->ipc_spin_lock, irq_flags);
-}
-
 void sst_configure_runtime_pm(struct intel_sst_drv *ctx)
 {
 	pm_runtime_set_autosuspend_delay(ctx->dev, SST_SUSPEND_DELAY);
@@ -416,8 +401,6 @@ void sst_configure_runtime_pm(struct intel_sst_drv *ctx)
 		pm_runtime_set_active(ctx->dev);
 	else
 		pm_runtime_put_noidle(ctx->dev);
-
-	sst_save_shim64(ctx, ctx->shim, ctx->shim_regs64);
 }
 EXPORT_SYMBOL_GPL(sst_configure_runtime_pm);
 
@@ -441,8 +424,6 @@ static int intel_sst_runtime_suspend(struct device *dev)
 	flush_workqueue(ctx->post_msg_wq);
 
 	ctx->ops->reset(ctx);
-	/* save the shim registers because PMC doesn't save state */
-	sst_save_shim64(ctx, ctx->shim, ctx->shim_regs64);
 
 	return ret;
 }

sound/soc/intel/atom/sst/sst.h

@@ -317,26 +317,6 @@ struct sst_ipc_reg {
 	int ipcd;
 };
 
-struct sst_shim_regs64 {
-	u64 csr;
-	u64 pisr;
-	u64 pimr;
-	u64 isrx;
-	u64 isrd;
-	u64 imrx;
-	u64 imrd;
-	u64 ipcx;
-	u64 ipcd;
-	u64 isrsc;
-	u64 isrlpesc;
-	u64 imrsc;
-	u64 imrlpesc;
-	u64 ipcsc;
-	u64 ipclpesc;
-	u64 clkctl;
-	u64 csr2;
-};
-
 struct sst_fw_save {
 	void *iram;
 	void *dram;
@@ -356,7 +336,6 @@ struct sst_fw_save {
  * @dram : SST DRAM pointer
  * @pdata : SST info passed as a part of pci platform data
  * @shim_phy_add : SST shim phy addr
- * @shim_regs64: Struct to save shim registers
  * @ipc_dispatch_list : ipc messages dispatched
  * @rx_list : to copy the process_reply/process_msg from DSP
  * @ipc_post_msg_wq : wq to post IPC messages context
@@ -398,7 +377,6 @@ struct intel_sst_drv {
 	unsigned int		ddr_end;
 	unsigned int		ddr_base;
 	unsigned int		mailbox_recv_offset;
-	struct sst_shim_regs64	*shim_regs64;
 	struct list_head        block_list;
 	struct list_head	ipc_dispatch_list;
 	struct sst_platform_info *pdata;

sound/soc/intel/atom/sst/sst_acpi.c

@@ -358,23 +358,9 @@ static int sst_acpi_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	/* need to save shim registers in BYT */
-	ctx->shim_regs64 = devm_kzalloc(ctx->dev, sizeof(*ctx->shim_regs64),
-					GFP_KERNEL);
-	if (!ctx->shim_regs64) {
-		ret = -ENOMEM;
-		goto do_sst_cleanup;
-	}
-
 	sst_configure_runtime_pm(ctx);
 	platform_set_drvdata(pdev, ctx);
 	return ret;
-
-do_sst_cleanup:
-	sst_context_cleanup(ctx);
-	platform_set_drvdata(pdev, NULL);
-	dev_err(ctx->dev, "failed with %d\n", ret);
-	return ret;
 }
 
 /**