Re: [PATCH RFC 2/3] ARM: regulator: add Freescale MXS regulator driver

Mark Rutland
2014-09-09T18:23:12Z

[...]

> + regs = (__raw_readl(sreg->base_addr) & ~BM_POWER_LEVEL_TRG);

I suspect you should be using the *_relaxed accessors rather than the
__raw_* accessors.

[...]

> +static int mxs_regulator_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev->of_node;
> + struct device_node *parent;
> + struct regulator_desc *rdesc;
> + struct regulator_dev *rdev;
> + struct mxs_regulator *sreg;
> + struct regulator_init_data *initdata;
> + struct regulation_constraints *con;
> + struct regulator_config config = { };
> + void __iomem *base_addr = NULL;
> + void __iomem *power_addr = NULL;
> + u64 regaddr64 = 0;
> + const u32 *regaddr_p;
> + u32 val = 0;
> + int ret;
> +
> + if (!np) {
> + dev_err(dev, "missing device tree\n");
> + return -EINVAL;
> + }
> +
> + /* get device base address */
> + base_addr = of_iomap(np, 0);
> + if (!base_addr)
> + return -ENXIO;
> +
> + parent = of_get_parent(np);
> + if (!parent)
> + return -ENXIO;

Leak of the (successfully mapped) base_addr.

> +
> + power_addr = of_iomap(parent, 0);
> + if (!power_addr)
> + return -ENXIO;

Leak of base_addr and dangling refcount on parent. These apply to all
subsequent returns.

> +
> + regaddr_p = of_get_address(np, 0, NULL, NULL);

of_get_address returns a __be32*, not a u32*, so sparse will be very
unhappy here...

> + if (regaddr_p)
> + regaddr64 = of_translate_address(np, regaddr_p);

...and as of_translate_address returns a u64 you'll need a separate
variable for the input and output.

> +
> + if (!regaddr64) {
> + dev_err(dev, "no or invalid reg property set\n");
> + return -EINVAL;
> + }
> +
> + initdata = of_get_regulator_init_data(dev, np);
> + if (!initdata)
> + return -EINVAL;
> +
> + ret = of_property_read_u32(np, "mxs-max-reg-val",
> + &val);
> + if (!val) {
> + dev_err(dev, "no or invalid mxs-max-reg-val property set\n");
> + return ret;
> + }
> +
> + dev_info(dev, "regulator found\n");
> +
> + sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
> + if (!sreg)
> + return -ENOMEM;
> + sreg->initdata = initdata;
> + sreg->name = of_get_property(np, "regulator-name", NULL);

I'm not keen on using of_get_property here. We have no idea if
regulator-name is even a string (it should be, but we have no
guarantee).

> + sreg->cur_uA = 0;
> + sreg->cur_uV = 0;
> + sreg->base_addr = base_addr;
> + sreg->power_addr = power_addr;
> + init_waitqueue_head(&sreg->wait_q);
> + spin_lock_init(&sreg->lock);
> + sreg->max_reg_val = val;
> +
> + rdesc = &sreg->rdesc;
> + rdesc->name = sreg->name;
> + rdesc->owner = THIS_MODULE;
> + rdesc->ops = &mxs_rops;
> +
> + if (strcmp(rdesc->name, "overall_current") == 0)
> + rdesc->type = REGULATOR_CURRENT;
> + else
> + rdesc->type = REGULATOR_VOLTAGE;

Wouldn't it make more sense to explicitly match the names you expect?

> + con = &initdata->constraints;
> + rdesc->n_voltages = sreg->max_reg_val;
> + rdesc->min_uV = con->min_uV;
> + rdesc->uV_step = (con->max_uV - con->min_uV) / sreg->max_reg_val;
> + rdesc->linear_min_sel = 0;
> + rdesc->vsel_reg = regaddr64;
> + rdesc->vsel_mask = BM_POWER_LEVEL_TRG;
> +
> + config.dev = &pdev->dev;
> + config.init_data = initdata;
> + config.driver_data = sreg;
> + config.of_node = np;
> +
> + pr_debug("probing regulator %s %s %d\n",
> + sreg->name,
> + rdesc->name,
> + pdev->id);

Aren't those two names always the same per the code above?

> +
> + /* register regulator */
> + rdev = devm_regulator_register(dev, rdesc, &config);
> +
> + if (IS_ERR(rdev)) {
> + dev_err(&pdev->dev, "failed to register %s\n",
> + rdesc->name);
> + return PTR_ERR(rdev);
> + }
> +
> + if (sreg->max_uA) {
> + struct regulator *regu;
> +
> + regu = regulator_get(NULL, sreg->name);
> + sreg->nb.notifier_call = reg_callback;
> + regulator_register_notifier(regu, &sreg->nb);
> + }
> +
> + platform_set_drvdata(pdev, rdev);
> +
> + of_property_read_u32(np, "mxs-default-microvolt",
> + &val);
> +
> + if (val)
> + mxs_set_voltage(rdev, val, val, NULL);

As I mentioned in my comments on the binding, I'd like to know why this
is necessary and if it is why it shouldn't be a standardised property.

Mark.