Hi Ivan,

On 08/15/2013 10:22 AM, Ivan T. Ivanov wrote:

Hi Georgi,

I have several comments below.

<snip>

Shouldn't we add required clocks here? It looks that some of them
are optional and others mandatory.

Yes, there are various clocks for MMC, SD/SDIO and at least 400mhz must 
be provided for the initialization process.
I'll create a device-tree properties for clocks. Thanks!

quoted

+#include <linux/types.h>
+#include <linux/input.h>

It seems that this is not required.

Correct, many of them are not required. Thanks!

quoted

+#define CORE_PWRCTL_STATUS	0xDC

Please use lower chars for hex numbers

Ok.

quoted

+/* This structure keeps information per regulator */
+struct sdhci_msm_reg_data {
+	/* voltage regulator handle */
+	struct regulator *reg;
+	/* regulator name */
+	const char *name;
+	/* voltage level to be set */
+	u32 low_vol_level;
+	u32 high_vol_level;
+	/* Load values for low power and high power mode */
+	u32 lpm_uA;
+	u32 hpm_uA;
+
+	/* is this regulator enabled? */
+	bool is_enabled;
+	/* is this regulator needs to be always on? */
+	bool is_always_on;
+	/* is low power mode setting required for this regulator? */
+	bool lpm_sup;
+};
+
+/*
+ * This structure keeps information for all the
+ * regulators required for a SDCC slot.
+ */
+struct sdhci_msm_slot_reg_data {
+	/* keeps VDD/VCC regulator info */
+	struct sdhci_msm_reg_data *vdd_data;
+	/* keeps VDD IO regulator info */
+	struct sdhci_msm_reg_data *vdd_io_data;

Why not allocate memory at once? I looks like both of
them are required.

Agree. I'll merge all of them into one structure. Thanks!

quoted

+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		dev_err(dev, "failed to allocate memory for platform data\n");
+		goto out;

Just return immediately? Here and bellow.

Ok.

quoted

+	/* Get the regulator handle */
+	vreg->reg = devm_regulator_get(dev, vreg->name);
+	if (IS_ERR(vreg->reg)) {
+		ret = PTR_ERR(vreg->reg);
+		pr_err("%s: devm_regulator_get(%s) failed. ret=%d\n",
+		       __func__, vreg->name, ret);

__func__ did not bring any additional info. Please remove it.

Ok.

quoted

+		goto out;
+	}
+
+	/* sanity check */
+	if (!vreg->high_vol_level || !vreg->hpm_uA) {
+		pr_err("%s: %s invalid constraints specified\n",
+		       __func__, vreg->name);

same thing ...

quoted

+		ret = -EINVAL;
+	}
+
+out:
+	return ret;
+}
+
+static void sdhci_msm_vreg_deinit_reg(struct sdhci_msm_reg_data *vreg)
+{
+	if (vreg->reg)

If regulator reference has to be checked it should be IS_ERR(vreg->reg).

quoted

+		devm_regulator_put(vreg->reg);

There is no need for this with device managed resources.

Ok.

quoted

+}
+
+static int sdhci_msm_vreg_set_optimum_mode(struct sdhci_msm_reg_data
+					   *vreg, int uA_load)
+{
+	int ret = 0;
+
+	/*
+	 * regulators that do not support regulator_set_voltage also
+	 * do not support regulator_set_optimum_mode
+	 */
+	ret = regulator_set_optimum_mode(vreg->reg, uA_load);
+	if (ret < 0)
+		pr_err
+		    ("%s: regulator_set_optimum_mode(%s,uA_load=%d) fail(%d)\n",
+		     __func__, vreg->name, uA_load, ret);
+	else
+		/*
+		 * regulator_set_optimum_mode() can return non zero
+		 * value even for success case.
+		 */
+		ret = 0;
+	return ret;

Is it really necessary to have function wrapper?

Will clean it.

quoted

+/* This init function should be called only once for each SDHC slot */
+static int sdhci_msm_vreg_init(struct device *dev,
+			       struct sdhci_msm_pltfm_data *pdata, bool is_init)
+{
+	int ret = 0;
+	struct sdhci_msm_slot_reg_data *curr_slot;
+	struct sdhci_msm_reg_data *curr_vdd_reg, *curr_vdd_io_reg;
+
+	curr_slot = pdata->vreg_data;
+	if (!curr_slot)

This could not happen.

quoted

+		goto out;
+
+	curr_vdd_reg = curr_slot->vdd_data;
+	curr_vdd_io_reg = curr_slot->vdd_io_data;
+
+	if (!is_init)
+		/* Deregister all regulators from regulator framework */
+		goto vdd_io_reg_deinit;
+
+	/*
+	 * Get the regulator handle from voltage regulator framework
+	 * and then try to set the voltage level for the regulator
+	 */
+	if (curr_vdd_reg) {

Why you check for this? It is alway true.

quoted

+		ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_reg);
+		if (ret)
+			goto out;
+	}
+	if (curr_vdd_io_reg) {
+		ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_io_reg);
+		if (ret)
+			goto vdd_reg_deinit;
+	}
+	ret = sdhci_msm_vreg_reset(pdata);
+	if (ret)
+		dev_err(dev, "vreg reset failed (%d)\n", ret);
+	goto out;
+
+vdd_io_reg_deinit:
+	if (curr_vdd_io_reg)
+		sdhci_msm_vreg_deinit_reg(curr_vdd_io_reg);
+vdd_reg_deinit:
+	if (curr_vdd_reg)
+		sdhci_msm_vreg_deinit_reg(curr_vdd_reg);
+out:
+	return ret;
+}
+
+static int sdhci_msm_set_vdd_io_vol(struct sdhci_msm_pltfm_data *pdata,
+				    enum vdd_io_level level,
+				    unsigned int voltage_level)
+{
+	int ret = 0;
+	int set_level;
+
+	if (pdata->vreg_data) {

When this will happen?

quoted

+		struct sdhci_msm_reg_data *vdd_io_reg =
+		    pdata->vreg_data->vdd_io_data;
+
+		if (vdd_io_reg && vdd_io_reg->is_enabled) {
+			switch (level) {
+			case VDD_IO_LOW:
+				set_level = vdd_io_reg->low_vol_level;
+				break;
+			case VDD_IO_HIGH:
+				set_level = vdd_io_reg->high_vol_level;
+				break;
+			case VDD_IO_SET_LEVEL:
+				set_level = voltage_level;
+				break;
+			default:
+				pr_err("%s: invalid argument level = %d",
+				       __func__, level);
+				ret = -EINVAL;
+				goto out;
+			}
+			ret = sdhci_msm_vreg_set_voltage(vdd_io_reg,
+							 set_level, set_level);
+		}
+	}
+
+out:
+	return ret;
+}
+
+static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
+{
+	struct sdhci_msm_host *msm_host = (struct sdhci_msm_host *)data;
+	u8 irq_status = 0;
+	u8 irq_ack = 0;
+	int ret = 0;
+
+	irq_status = readb_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
+	pr_debug("%s: Received IRQ(%d), status=0x%x\n",
+		 mmc_hostname(msm_host->mmc), irq, irq_status);
+
+	/* Clear the interrupt */
+	writeb_relaxed(irq_status, (msm_host->core_mem + CORE_PWRCTL_CLEAR));
+	/*
+	 * SDHC has core_mem and hc_mem device memory and these memory
+	 * addresses do not fall within 1KB region. Hence, any update to
+	 * core_mem address space would require an mb() to ensure this gets
+	 * completed before its next update to registers within hc_mem.
+	 */
+	mb();
+
+	/* Handle BUS ON/OFF */
+	if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF)) {
+		bool flag = (irq_status & CORE_PWRCTL_BUS_ON) ? 1 : 0;
+		ret = sdhci_msm_setup_vreg(msm_host->pdata, flag, false);
+		if (ret)
+			irq_ack |= CORE_PWRCTL_BUS_FAIL;
+		else
+			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		goto out;

goto out?

quoted

+	}
+	/* Handle IO LOW/HIGH */
+	if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH)) {
+		/* Switch voltage */
+		int io_status = (irq_status & CORE_PWRCTL_IO_LOW) ?
+		    VDD_IO_LOW : VDD_IO_HIGH;
+		ret = sdhci_msm_set_vdd_io_vol(msm_host->pdata, io_status, 0);
+		if (ret)
+			irq_ack |= CORE_PWRCTL_IO_FAIL;
+		else
+			irq_ack |= CORE_PWRCTL_IO_SUCCESS;
+		goto out;

Ditto.

quoted

+	}
+
+out:

quoted

+	/* ACK status to the core */
+	writeb_relaxed(irq_ack, (msm_host->core_mem + CORE_PWRCTL_CTL));
+	/*
+	 * SDHC has core_mem and hc_mem device memory and these memory
+	 * addresses do not fall within 1KB region. Hence, any update to
+	 * core_mem address space would require an mb() to ensure this gets
+	 * completed before its next update to registers within hc_mem.
+	 */
+	mb();
+
+	pr_debug("%s: Handled IRQ(%d), ret=%d, ack=0x%x\n",
+		 mmc_hostname(msm_host->mmc), irq, ret, irq_ack);
+	return IRQ_HANDLED;
+}
+
+/* This function returns the max. current supported by VDD rail in mA */
+static unsigned int sdhci_msm_get_vreg_vdd_max_current(struct sdhci_msm_host
+						       *host)
+{
+	struct sdhci_msm_slot_reg_data *curr_slot = host->pdata->vreg_data;
+	if (!curr_slot)
+		return 0;
+	if (curr_slot->vdd_data)
+		return curr_slot->vdd_data->hpm_uA / 1000;
+	else

Is this possible?

quoted

+		return 0;
+}
+
+static const struct of_device_id sdhci_msm_dt_match[] = {
+	{.compatible = "qcom,sdhci-msm"},
+};
+
+MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
+
+static int sdhci_msm_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct sdhci_host *host;
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_msm_host *msm_host;
+	struct resource *core_memres = NULL;
+	int ret = 0, dead = 0;
+	struct pinctrl	*pinctrl;
+
+	match = of_match_device(of_match_ptr(sdhci_msm_dt_match), &pdev->dev);
+	if (!match)

Is this possible?

No, it's not needed. Will remove it.

quoted

+		return -ENXIO;
+
+	msm_host = devm_kzalloc(&pdev->dev, sizeof(struct sdhci_msm_host),
+				GFP_KERNEL);
+	if (!msm_host) {
+		ret = -ENOMEM;

Just return -ENOMEM?

Ok.

quoted

+	/* Setup Clocks */
+
+	/* Setup SDCC bus voter clock. */
+	msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus_clk");
+	if (!IS_ERR_OR_NULL(msm_host->bus_clk)) {

This should be !IS_ERR(). Is this clock optional?

Yes, it's optional.

quoted

+		/* Vote for max. clk rate for max. performance */
+		ret = clk_set_rate(msm_host->bus_clk, INT_MAX);
+		if (ret)
+			goto pltfm_free;
+		ret = clk_prepare_enable(msm_host->bus_clk);
+		if (ret)
+			goto pltfm_free;
+	}
+
+	/* Setup main peripheral bus clock */
+	msm_host->pclk = devm_clk_get(&pdev->dev, "iface_clk");

Is this clock optional?

Yes, its optional.

quoted

+
+	host->mmc->max_current_180 =
+	    sdhci_msm_get_vreg_vdd_max_current(msm_host);
+	host->mmc->max_current_300 =
+	    sdhci_msm_get_vreg_vdd_max_current(msm_host);
+	host->mmc->max_current_330 =
+	    sdhci_msm_get_vreg_vdd_max_current(msm_host);

Is it expected that this function to return different result
after each call?

Very unlikely. Will review and change it.

quoted

+
+	/* Successful initialization */
+	goto out;
+
+remove_host:
+	dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
+	sdhci_remove_host(host, dead);
+vreg_deinit:
+	sdhci_msm_vreg_init(&pdev->dev, msm_host->pdata, false);
+clk_disable:
+	if (!IS_ERR(msm_host->clk))
+		clk_disable_unprepare(msm_host->clk);
+pclk_disable:
+	if (!IS_ERR(msm_host->pclk))
+		clk_disable_unprepare(msm_host->pclk);
+bus_clk_disable:
+	if (!IS_ERR_OR_NULL(msm_host->bus_clk))
+		clk_disable_unprepare(msm_host->bus_clk);
+pltfm_free:
+	sdhci_pltfm_free(pdev);
+out:
+	return ret;
+}
+
+static int sdhci_msm_remove(struct platform_device *pdev)
+{
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = pltfm_host->priv;
+	int dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
+		    0xffffffff);
+
+	pr_debug("%s: %s\n", dev_name(&pdev->dev), __func__);
+	sdhci_remove_host(host, dead);
+	sdhci_pltfm_free(pdev);
+	sdhci_msm_vreg_init(&pdev->dev, msm_host->pdata, false);
+	if (!IS_ERR(msm_host->clk))

This is always true.

It should be, otherwise we will fail at probe. I will review the sanity 
checks and clean-up where necessary. Thanks!

quoted

+		clk_disable_unprepare(msm_host->clk);
+	if (!IS_ERR(msm_host->pclk))
+		clk_disable_unprepare(msm_host->pclk);
+	if (!IS_ERR_OR_NULL(msm_host->bus_clk))

!IS_ERR. And this could happen only if clock is optional.

Correct.

Thank you for detailed review and all the comments!

BR,
Georgi