From 156c5887948cd191417f18026aab9ce26e5a95da Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sat, 22 Feb 2014 16:53:31 +0100 Subject: 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 Signed-off-by: Tejun Heo --- .../devicetree/bindings/ata/ahci-platform.txt | 1 + drivers/ata/ahci.h | 3 +- drivers/ata/ahci_platform.c | 113 ++++++++++++++++----- include/linux/ahci_platform.h | 4 + 4 files changed, 93 insertions(+), 28 deletions(-) diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt index 89de1564950c..3ced07dc8f56 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@ffe08000 { diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h index 64d1a99de5e4..c12862bd48ee 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 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; } diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h index 73a25005d88a..769d06525320 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 */ -- cgit v1.2.3-59-g8ed1b