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authorHans de Goede <hdegoede@redhat.com>2014-02-22 16:53:31 +0100
committerTejun Heo <tj@kernel.org>2014-02-22 15:35:41 -0500
commit156c5887948cd191417f18026aab9ce26e5a95da (patch)
tree65100ae8c89fec69d8f949ceb9b9b413a6af3468 /drivers/ata/ahci_platform.c
parent039ece38da45f5e6a94be3aa7611cf3634bc2461 (diff)
downloadlinux-156c5887948cd191417f18026aab9ce26e5a95da.tar.bz2
ahci-platform: Add support for devices with more then 1 clock
The allwinner-sun4i AHCI controller needs 2 clocks to be enabled and the imx AHCI controller needs 3 clocks to be enabled. tj: Minor comment formatting updates. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/ata/ahci_platform.c')
-rw-r--r--drivers/ata/ahci_platform.c113
1 files changed, 86 insertions, 27 deletions
diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 9302d8143393..8d5a9a7ce958 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -86,6 +86,60 @@ static struct scsi_host_template ahci_platform_sht = {
AHCI_SHT("ahci_platform"),
};
+/**
+ * ahci_platform_enable_clks - Enable platform clocks
+ * @hpriv: host private area to store config values
+ *
+ * This function enables all the clks found in hpriv->clks, starting at
+ * index 0. If any clk fails to enable it disables all the clks already
+ * enabled in reverse order, and then returns an error.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_enable_clks(struct ahci_host_priv *hpriv)
+{
+ int c, rc;
+
+ for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++) {
+ rc = clk_prepare_enable(hpriv->clks[c]);
+ if (rc)
+ goto disable_unprepare_clk;
+ }
+ return 0;
+
+disable_unprepare_clk:
+ while (--c >= 0)
+ clk_disable_unprepare(hpriv->clks[c]);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_enable_clks);
+
+/**
+ * ahci_platform_disable_clks - Disable platform clocks
+ * @hpriv: host private area to store config values
+ *
+ * This function disables all the clks found in hpriv->clks, in reverse
+ * order of ahci_platform_enable_clks (starting at the end of the array).
+ */
+void ahci_platform_disable_clks(struct ahci_host_priv *hpriv)
+{
+ int c;
+
+ for (c = AHCI_MAX_CLKS - 1; c >= 0; c--)
+ if (hpriv->clks[c])
+ clk_disable_unprepare(hpriv->clks[c]);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_disable_clks);
+
+static void ahci_put_clks(struct ahci_host_priv *hpriv)
+{
+ int c;
+
+ for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
+ clk_put(hpriv->clks[c]);
+}
+
static int ahci_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -96,6 +150,7 @@ static int ahci_probe(struct platform_device *pdev)
struct ahci_host_priv *hpriv;
struct ata_host *host;
struct resource *mem;
+ struct clk *clk;
int irq;
int n_ports;
int i;
@@ -130,17 +185,31 @@ static int ahci_probe(struct platform_device *pdev)
return -ENOMEM;
}
- hpriv->clk = clk_get(dev, NULL);
- if (IS_ERR(hpriv->clk)) {
- dev_err(dev, "can't get clock\n");
- } else {
- rc = clk_prepare_enable(hpriv->clk);
- if (rc) {
- dev_err(dev, "clock prepare enable failed");
- goto free_clk;
+ for (i = 0; i < AHCI_MAX_CLKS; i++) {
+ /*
+ * For now we must use clk_get(dev, NULL) for the first clock,
+ * because some platforms (da850, spear13xx) are not yet
+ * converted to use devicetree for clocks. For new platforms
+ * this is equivalent to of_clk_get(dev->of_node, 0).
+ */
+ if (i == 0)
+ clk = clk_get(dev, NULL);
+ else
+ clk = of_clk_get(dev->of_node, i);
+
+ if (IS_ERR(clk)) {
+ rc = PTR_ERR(clk);
+ if (rc == -EPROBE_DEFER)
+ goto free_clk;
+ break;
}
+ hpriv->clks[i] = clk;
}
+ rc = ahci_enable_clks(dev, hpriv);
+ if (rc)
+ goto free_clk;
+
/*
* Some platforms might need to prepare for mmio region access,
* which could be done in the following init call. So, the mmio
@@ -221,11 +290,9 @@ pdata_exit:
if (pdata && pdata->exit)
pdata->exit(dev);
disable_unprepare_clk:
- if (!IS_ERR(hpriv->clk))
- clk_disable_unprepare(hpriv->clk);
+ ahci_disable_clks(hpriv);
free_clk:
- if (!IS_ERR(hpriv->clk))
- clk_put(hpriv->clk);
+ ahci_put_clks(hpriv);
return rc;
}
@@ -238,10 +305,8 @@ static void ahci_host_stop(struct ata_host *host)
if (pdata && pdata->exit)
pdata->exit(dev);
- if (!IS_ERR(hpriv->clk)) {
- clk_disable_unprepare(hpriv->clk);
- clk_put(hpriv->clk);
- }
+ ahci_disable_clks(hpriv);
+ ahci_put_clks(hpriv);
}
#ifdef CONFIG_PM_SLEEP
@@ -276,8 +341,7 @@ static int ahci_suspend(struct device *dev)
if (pdata && pdata->suspend)
return pdata->suspend(dev);
- if (!IS_ERR(hpriv->clk))
- clk_disable_unprepare(hpriv->clk);
+ ahci_disable_clks(hpriv);
return 0;
}
@@ -289,13 +353,9 @@ static int ahci_resume(struct device *dev)
struct ahci_host_priv *hpriv = host->private_data;
int rc;
- if (!IS_ERR(hpriv->clk)) {
- rc = clk_prepare_enable(hpriv->clk);
- if (rc) {
- dev_err(dev, "clock prepare enable failed");
- return rc;
- }
- }
+ rc = ahci_enable_clks(dev, hpriv);
+ if (rc)
+ return rc;
if (pdata && pdata->resume) {
rc = pdata->resume(dev);
@@ -316,8 +376,7 @@ static int ahci_resume(struct device *dev)
return 0;
disable_unprepare_clk:
- if (!IS_ERR(hpriv->clk))
- clk_disable_unprepare(hpriv->clk);
+ ahci_disable_clks(hpriv);
return rc;
}