Re: [PATCH v3 3/4] ata: libahci: Allow using multiple regulators
From: Gregory CLEMENT
Date: Thu Jan 15 2015 - 05:51:02 EST
Hi Hans,
On 15/01/2015 09:46, Hans de Goede wrote:
> Hi,
>
> On 13-01-15 15:22, Gregory CLEMENT wrote:
>> The current implementation of the libahci allows using multiple PHYs
>> but not multiple regulators. This patch adds the support of multiple
>> regulators. Until now it was mandatory to have a PHY under a subnode,
>> now a port subnode can contain either a regulator or a PHY (or both).
>>
>> In order to be able to asociate a port with a regulator the port are
>> now a platform device in the device tree case.
>>
>> There was only one driver which used directly the regulator field of
>> the ahci_host_priv structure. To preserve the bisectability the change
>> in the ahci_imx driver was done in the same patch.
>>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
>
> Looks good, still needs one more (small) revision though, see comments
> inline.
OK I will take care of it
Thanks,
Gregory
>
>> ---
>> drivers/ata/ahci.h | 2 +-
>> drivers/ata/ahci_imx.c | 14 +--
>> drivers/ata/libahci_platform.c | 227 +++++++++++++++++++++++++++++------------
>> include/linux/ahci_platform.h | 2 +
>> 4 files changed, 170 insertions(+), 75 deletions(-)
>>
>> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
>> index 40f0e34f17af..275358ae0b3f 100644
>> --- a/drivers/ata/ahci.h
>> +++ b/drivers/ata/ahci.h
>> @@ -333,7 +333,7 @@ struct ahci_host_priv {
>> u32 em_msg_type; /* EM message type */
>> bool got_runtime_pm; /* Did we do pm_runtime_get? */
>> struct clk *clks[AHCI_MAX_CLKS]; /* Optional */
>> - struct regulator *target_pwr; /* Optional */
>> + struct regulator **target_pwrs; /* Optional */
>> /*
>> * If platform uses PHYs. There is a 1:1 relation between the port number and
>> * the PHY position in this array.
>> diff --git a/drivers/ata/ahci_imx.c b/drivers/ata/ahci_imx.c
>> index 35d51c59a370..41632e57d46f 100644
>> --- a/drivers/ata/ahci_imx.c
>> +++ b/drivers/ata/ahci_imx.c
>> @@ -221,11 +221,9 @@ static int imx_sata_enable(struct ahci_host_priv *hpriv)
>> if (imxpriv->no_device)
>> return 0;
>>
>> - if (hpriv->target_pwr) {
>> - ret = regulator_enable(hpriv->target_pwr);
>> - if (ret)
>> - return ret;
>> - }
>> + ret = ahci_platform_enable_regulators(hpriv);
>> + if (ret)
>> + return ret;
>>
>> ret = clk_prepare_enable(imxpriv->sata_ref_clk);
>> if (ret < 0)
>> @@ -270,8 +268,7 @@ static int imx_sata_enable(struct ahci_host_priv *hpriv)
>> disable_clk:
>> clk_disable_unprepare(imxpriv->sata_ref_clk);
>> disable_regulator:
>> - if (hpriv->target_pwr)
>> - regulator_disable(hpriv->target_pwr);
>> + ahci_platform_disable_regulators(hpriv);
>>
>> return ret;
>> }
>> @@ -291,8 +288,7 @@ static void imx_sata_disable(struct ahci_host_priv *hpriv)
>>
>> clk_disable_unprepare(imxpriv->sata_ref_clk);
>>
>> - if (hpriv->target_pwr)
>> - regulator_disable(hpriv->target_pwr);
>> + ahci_platform_disable_regulators(hpriv);
>> }
>>
>> static void ahci_imx_error_handler(struct ata_port *ap)
>> diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
>> index a147aaadca85..1db968ef6ff8 100644
>> --- a/drivers/ata/libahci_platform.c
>> +++ b/drivers/ata/libahci_platform.c
>> @@ -24,6 +24,7 @@
>> #include <linux/ahci_platform.h>
>> #include <linux/phy/phy.h>
>> #include <linux/pm_runtime.h>
>> +#include <linux/of_platform.h>
>> #include "ahci.h"
>>
>> static void ahci_host_stop(struct ata_host *host);
>> @@ -138,6 +139,59 @@ void ahci_platform_disable_clks(struct ahci_host_priv *hpriv)
>> EXPORT_SYMBOL_GPL(ahci_platform_disable_clks);
>>
>> /**
>> + * ahci_platform_enable_regulators - Enable regulators
>> + * @hpriv: host private area to store config values
>> + *
>> + * This function enables all the regulators found in
>> + * hpriv->target_pwrs, if any. If a regulator fails to be enabled, it
>> + * disables all the regulators already enabled in reverse order and
>> + * returns an error.
>> + *
>> + * RETURNS:
>> + * 0 on success otherwise a negative error code
>> + */
>> +int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv)
>> +{
>> + int rc, i;
>> +
>> + for (i = 0; i < hpriv->nports; i++) {
>> + if (!hpriv->target_pwrs[i])
>> + continue;
>> +
>> + rc = regulator_enable(hpriv->target_pwrs[i]);
>> + if (rc)
>> + goto disable_target_pwrs;
>> + }
>> +
>> + return 0;
>> +
>> +disable_target_pwrs:
>> + while (--i >= 0)
>> + if (hpriv->target_pwrs[i])
>> + regulator_disable(hpriv->target_pwrs[i]);
>> +
>> + return rc;
>> +}
>> +EXPORT_SYMBOL_GPL(ahci_platform_enable_regulators);
>> +
>> +/**
>> + * ahci_platform_disable_regulators - Disable regulators
>> + * @hpriv: host private area to store config values
>> + *
>> + * This function disables all regulators found in hpriv->target_pwrs.
>> + */
>> +void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < hpriv->nports; i++) {
>> + if (!hpriv->target_pwrs[i])
>> + continue;
>> + regulator_disable(hpriv->target_pwrs[i]);
>> + }
>> +}
>> +EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
>> +/**
>> * ahci_platform_enable_resources - Enable platform resources
>> * @hpriv: host private area to store config values
>> *
>> @@ -157,11 +211,9 @@ int ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
>> {
>> int rc;
>>
>> - if (hpriv->target_pwr) {
>> - rc = regulator_enable(hpriv->target_pwr);
>> - if (rc)
>> - return rc;
>> - }
>> + rc = ahci_platform_enable_regulators(hpriv);
>> + if (rc)
>> + return rc;
>>
>> rc = ahci_platform_enable_clks(hpriv);
>> if (rc)
>> @@ -177,8 +229,8 @@ disable_clks:
>> ahci_platform_disable_clks(hpriv);
>>
>> disable_regulator:
>> - if (hpriv->target_pwr)
>> - regulator_disable(hpriv->target_pwr);
>> + ahci_platform_disable_regulators(hpriv);
>> +
>> return rc;
>> }
>> EXPORT_SYMBOL_GPL(ahci_platform_enable_resources);
>> @@ -199,8 +251,7 @@ void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
>>
>> ahci_platform_disable_clks(hpriv);
>>
>> - if (hpriv->target_pwr)
>> - regulator_disable(hpriv->target_pwr);
>> + ahci_platform_disable_regulators(hpriv);
>> }
>> EXPORT_SYMBOL_GPL(ahci_platform_disable_resources);
>>
>> @@ -218,6 +269,59 @@ static void ahci_platform_put_resources(struct device *dev, void *res)
>> clk_put(hpriv->clks[c]);
>> }
>>
>> +static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port,
>> + struct device *dev, struct device_node *node)
>> +{
>> + int rc;
>> +
>> + hpriv->phys[port] = devm_of_phy_get(dev, node, NULL);
>> +
>> + if (!IS_ERR(hpriv->phys[port]))
>> + return 0;
>> +
>> + rc = PTR_ERR(hpriv->phys[port]);
>> + switch (rc) {
>> + case -ENOSYS:
>> + /* No PHY support. Check if PHY is required. */
>> + if (of_find_property(node, "phys", NULL)) {
>> + dev_err(dev,
>> + "couldn't get PHY in node %s: ENOSYS\n",
>> + node->name);
>> + break;
>> + }
>> + case -ENODEV:
>> + /* continue normally */
>> + hpriv->phys[port] = NULL;
>> + rc = 0;
>> + break;
>> +
>> + default:
>> + dev_err(dev,
>> + "couldn't get PHY in node %s: %d\n",
>> + node->name, rc);
>> +
>> + break;
>> + }
>> +
>> + return rc;
>> +}
>> +
>> +static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port,
>> + struct device *dev)
>> +{
>> + struct regulator *target_pwr;
>> + int rc = 0;
>> +
>> + target_pwr = devm_regulator_get_optional(dev, "target");
>
> As you've already found out the devm framework does not work for freeing
> things which are tied to the child node devices, so it is better to
> use the non devm function here, the devm variant just adds overhead
> (extra malloc under the hood), without buying us anything here.
>
>> +
>> + if (!IS_ERR(target_pwr))
>> + hpriv->target_pwrs[port] = target_pwr;
>> + else
>> + rc = PTR_ERR(target_pwr);
>> +
>> + return rc;
>> +}
>> +
>> /**
>> * ahci_platform_get_resources - Get platform resources
>> * @pdev: platform device to get resources for
>
>
> You're not modifying ahci_platform_put_resources to put the regulators here,
> since the regulators may now be bound to the platfrom-devs for the child nodes,
> they will not get cleaned up by the devm framework on driver unbind, as the
> driver is only bound to the main device and thus the devm framework only
> cleans up resources attached to the main device.
>
> So you need to modify ahci_platform_put_resources to explicitly put the
> reference to the regulators.
>
> Note since ahci_platform_put_resources gets called during probe errors too,
> you need to check hpriv->target_pwrs before you deref it as it may be NULL!
>
> Please also add a comment to ahci_platform_put_resources why the regulators
> cannot be devm managed.
>
>> @@ -240,7 +344,7 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
>> struct ahci_host_priv *hpriv;
>> struct clk *clk;
>> struct device_node *child;
>> - int i, enabled_ports = 0, rc = -ENOMEM;
>> + int i, sz, enabled_ports = 0, rc = -ENOMEM, child_nodes;
>> u32 mask_port_map = 0;
>>
>> if (!devres_open_group(dev, NULL, GFP_KERNEL))
>> @@ -261,14 +365,6 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
>> goto err_out;
>> }
>>
>> - hpriv->target_pwr = devm_regulator_get_optional(dev, "target");
>> - if (IS_ERR(hpriv->target_pwr)) {
>> - rc = PTR_ERR(hpriv->target_pwr);
>> - if (rc == -EPROBE_DEFER)
>> - goto err_out;
>> - hpriv->target_pwr = NULL;
>> - }
>> -
>> for (i = 0; i < AHCI_MAX_CLKS; i++) {
>> /*
>> * For now we must use clk_get(dev, NULL) for the first clock,
>> @@ -290,19 +386,33 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
>> hpriv->clks[i] = clk;
>> }
>>
>> - hpriv->nports = of_get_child_count(dev->of_node);
>> + hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
>>
>> - if (hpriv->nports) {
>> - hpriv->phys = devm_kzalloc(dev,
>> - hpriv->nports * sizeof(*hpriv->phys),
>> - GFP_KERNEL);
>> - if (!hpriv->phys) {
>> - rc = -ENOMEM;
>> - goto err_out;
>> - }
>> + /*
>> + * If no sub-node was found, we still need to set nports to
>> + * one in order to be able to use the
>> + * ahci_platform_[en|dis]able_[phys|regulators] functions.
>> + */
>> + if (!child_nodes)
>> + hpriv->nports = 1;
>> +
>> + sz = hpriv->nports * sizeof(*hpriv->phys);
>> + hpriv->phys = devm_kzalloc(dev, sz, GFP_KERNEL);
>> + if (!hpriv->phys) {
>> + rc = -ENOMEM;
>> + goto err_out;
>> + }
>> + sz = hpriv->nports * sizeof(*hpriv->target_pwrs);
>> + hpriv->target_pwrs = devm_kzalloc(dev, sz, GFP_KERNEL);
>> + if (!hpriv->target_pwrs) {
>> + rc = -ENOMEM;
>> + goto err_out;
>> + }
>>
>> + if (child_nodes) {
>> for_each_child_of_node(dev->of_node, child) {
>> u32 port;
>> + struct platform_device *port_dev;
>>
>> if (!of_device_is_available(child))
>> continue;
>> @@ -316,17 +426,20 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
>> dev_warn(dev, "invalid port number %d\n", port);
>> continue;
>> }
>> -
>> mask_port_map |= BIT(port);
>>
>> - hpriv->phys[port] = devm_of_phy_get(dev, child, NULL);
>> - if (IS_ERR(hpriv->phys[port])) {
>> - rc = PTR_ERR(hpriv->phys[port]);
>> - dev_err(dev,
>> - "couldn't get PHY in node %s: %d\n",
>> - child->name, rc);
>> + of_platform_device_create(child, NULL, NULL);
>> +
>> + port_dev = of_find_device_by_node(child);
>
> This call can fail, you need to error check it before dereferencing the port_dev
> pointer below.
>
>> +
>> + rc = ahci_platform_get_regulator(hpriv, port,
>> + &port_dev->dev);
>> + if (rc == -EPROBE_DEFER)
>> + goto err_out;
>> +
>> + rc = ahci_platform_get_phy(hpriv, port, dev, child);
>> + if (rc)
>> goto err_out;
>> - }
>>
>> enabled_ports++;
>> }
>> @@ -343,38 +456,14 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
>> * If no sub-node was found, keep this for device tree
>> * compatibility
>> */
>> - struct phy *phy = devm_phy_get(dev, "sata-phy");
>> - if (!IS_ERR(phy)) {
>> - hpriv->phys = devm_kzalloc(dev, sizeof(*hpriv->phys),
>> - GFP_KERNEL);
>> - if (!hpriv->phys) {
>> - rc = -ENOMEM;
>> - goto err_out;
>> - }
>> -
>> - hpriv->phys[0] = phy;
>> - hpriv->nports = 1;
>> - } else {
>> - rc = PTR_ERR(phy);
>> - switch (rc) {
>> - case -ENOSYS:
>> - /* No PHY support. Check if PHY is required. */
>> - if (of_find_property(dev->of_node, "phys", NULL)) {
>> - dev_err(dev, "couldn't get sata-phy: ENOSYS\n");
>> - goto err_out;
>> - }
>> - case -ENODEV:
>> - /* continue normally */
>> - hpriv->phys = NULL;
>> - break;
>> -
>> - default:
>> - goto err_out;
>> + rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
>> + if (rc)
>> + goto err_out;
>>
>> - }
>> - }
>> + rc = ahci_platform_get_regulator(hpriv, 0, dev);
>> + if (rc == -EPROBE_DEFER)
>> + goto err_out;
>> }
>> -
>> pm_runtime_enable(dev);
>> pm_runtime_get_sync(dev);
>> hpriv->got_runtime_pm = true;
>> @@ -383,6 +472,14 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
>> return hpriv;
>>
>> err_out:
>> + /*
>> + * In case of a deferred probe, previous regulators may have
>> + * been already get, so put them to be able to get them again
>> + * in the next probe.
>> + */
>> + for (i = 0; i < hpriv->nports; i++)
>> + if (hpriv->target_pwrs[i])
>> + devm_regulator_put(hpriv->target_pwrs[i]);
>
> Once you've added the regulator_put calls to ahci_platform_put_resources
> you can drop this as the devres_release_group() call will call
> ahci_platform_put_resources().
>
>> devres_release_group(dev, NULL);
>> return ERR_PTR(rc);
>> }
>> diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h
>> index 642d6ae4030c..f65b33809170 100644
>> --- a/include/linux/ahci_platform.h
>> +++ b/include/linux/ahci_platform.h
>> @@ -24,6 +24,8 @@ struct platform_device;
>>
>> int ahci_platform_enable_clks(struct ahci_host_priv *hpriv);
>> void ahci_platform_disable_clks(struct ahci_host_priv *hpriv);
>> +int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv);
>> +void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv);
>> int ahci_platform_enable_resources(struct ahci_host_priv *hpriv);
>> void ahci_platform_disable_resources(struct ahci_host_priv *hpriv);
>> struct ahci_host_priv *ahci_platform_get_resources(
>>
>
> Regards,
>
> Hans
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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