[PATCH v7 02/15] ahci-platform: Add support for devices with more then 1 clock
Hans de Goede
hdegoede at redhat.com
Sat Feb 22 10:53:31 EST 2014
The allwinner-sun4i AHCI controller needs 2 clocks to be enabled and the
imx AHCI controller needs 3 clocks to be enabled.
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
.../devicetree/bindings/ata/ahci-platform.txt | 1 +
drivers/ata/ahci.h | 3 +-
drivers/ata/ahci_platform.c | 119 ++++++++++++++++-----
include/linux/ahci_platform.h | 4 +
4 files changed, 99 insertions(+), 28 deletions(-)
diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt
index 89de156..3ced07d 100644
--- a/Documentation/devicetree/bindings/ata/ahci-platform.txt
+++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt
@@ -10,6 +10,7 @@ Required properties:
Optional properties:
- dma-coherent : Present if dma operations are coherent
+- clocks : a list of phandle + clock specifier pairs
Example:
sata at ffe08000 {
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 64d1a99..c12862b 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -51,6 +51,7 @@
enum {
AHCI_MAX_PORTS = 32,
+ AHCI_MAX_CLKS = 3,
AHCI_MAX_SG = 168, /* hardware max is 64K */
AHCI_DMA_BOUNDARY = 0xffffffff,
AHCI_MAX_CMDS = 32,
@@ -321,7 +322,7 @@ struct ahci_host_priv {
u32 em_loc; /* enclosure management location */
u32 em_buf_sz; /* EM buffer size in byte */
u32 em_msg_type; /* EM message type */
- struct clk *clk; /* Only for platforms supporting clk */
+ struct clk *clks[AHCI_MAX_CLKS]; /* Optional */
void *plat_data; /* Other platform data */
/*
* Optional ahci_start_engine override, if not set this gets set to the
diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 4b231ba..609975d 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -87,6 +87,66 @@ 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.
+ *
+ * LOCKING:
+ * None.
+ *
+ * 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).
+ *
+ * LOCKING:
+ * None.
+ */
+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;
@@ -97,6 +157,7 @@ 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;
@@ -131,17 +192,31 @@ 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
@@ -222,11 +297,9 @@ 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;
}
@@ -239,10 +312,8 @@ 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
@@ -277,8 +348,7 @@ 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;
}
@@ -290,13 +360,9 @@ 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);
@@ -317,8 +383,7 @@ 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;
}
diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h
index 73a2500..769d065 100644
--- a/include/linux/ahci_platform.h
+++ b/include/linux/ahci_platform.h
@@ -19,6 +19,7 @@
struct device;
struct ata_port_info;
+struct ahci_host_priv;
struct ahci_platform_data {
int (*init)(struct device *dev, void __iomem *addr);
@@ -30,4 +31,7 @@ struct ahci_platform_data {
unsigned int mask_port_map;
};
+int ahci_platform_enable_clks(struct ahci_host_priv *hpriv);
+void ahci_platform_disable_clks(struct ahci_host_priv *hpriv);
+
#endif /* _AHCI_PLATFORM_H */
--
1.9.0
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