linux/drivers/bus/qcom-ssc-block-bus.c
Uwe Kleine-König ea7964a660 bus: qcom-ssc-block-bus: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Link: https://lore.kernel.org/r/20231109202830.4124591-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2023-11-28 18:43:26 +01:00

387 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2021, Michael Srba
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_clock.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/reset.h>
/* AXI Halt Register Offsets */
#define AXI_HALTREQ_REG 0x0
#define AXI_HALTACK_REG 0x4
#define AXI_IDLE_REG 0x8
#define SSCAON_CONFIG0_CLAMP_EN_OVRD BIT(4)
#define SSCAON_CONFIG0_CLAMP_EN_OVRD_VAL BIT(5)
static const char *const qcom_ssc_block_pd_names[] = {
"ssc_cx",
"ssc_mx"
};
struct qcom_ssc_block_bus_data {
const char *const *pd_names;
struct device *pds[ARRAY_SIZE(qcom_ssc_block_pd_names)];
char __iomem *reg_mpm_sscaon_config0;
char __iomem *reg_mpm_sscaon_config1;
struct regmap *halt_map;
struct clk *xo_clk;
struct clk *aggre2_clk;
struct clk *gcc_im_sleep_clk;
struct clk *aggre2_north_clk;
struct clk *ssc_xo_clk;
struct clk *ssc_ahbs_clk;
struct reset_control *ssc_bcr;
struct reset_control *ssc_reset;
u32 ssc_axi_halt;
int num_pds;
};
static void reg32_set_bits(char __iomem *reg, u32 value)
{
u32 tmp = ioread32(reg);
iowrite32(tmp | value, reg);
}
static void reg32_clear_bits(char __iomem *reg, u32 value)
{
u32 tmp = ioread32(reg);
iowrite32(tmp & (~value), reg);
}
static int qcom_ssc_block_bus_init(struct device *dev)
{
int ret;
struct qcom_ssc_block_bus_data *data = dev_get_drvdata(dev);
ret = clk_prepare_enable(data->xo_clk);
if (ret) {
dev_err(dev, "error enabling xo_clk: %d\n", ret);
goto err_xo_clk;
}
ret = clk_prepare_enable(data->aggre2_clk);
if (ret) {
dev_err(dev, "error enabling aggre2_clk: %d\n", ret);
goto err_aggre2_clk;
}
ret = clk_prepare_enable(data->gcc_im_sleep_clk);
if (ret) {
dev_err(dev, "error enabling gcc_im_sleep_clk: %d\n", ret);
goto err_gcc_im_sleep_clk;
}
/*
* We need to intervene here because the HW logic driving these signals cannot handle
* initialization after power collapse by itself.
*/
reg32_clear_bits(data->reg_mpm_sscaon_config0,
SSCAON_CONFIG0_CLAMP_EN_OVRD | SSCAON_CONFIG0_CLAMP_EN_OVRD_VAL);
/* override few_ack/rest_ack */
reg32_clear_bits(data->reg_mpm_sscaon_config1, BIT(31));
ret = clk_prepare_enable(data->aggre2_north_clk);
if (ret) {
dev_err(dev, "error enabling aggre2_north_clk: %d\n", ret);
goto err_aggre2_north_clk;
}
ret = reset_control_deassert(data->ssc_reset);
if (ret) {
dev_err(dev, "error deasserting ssc_reset: %d\n", ret);
goto err_ssc_reset;
}
ret = reset_control_deassert(data->ssc_bcr);
if (ret) {
dev_err(dev, "error deasserting ssc_bcr: %d\n", ret);
goto err_ssc_bcr;
}
regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 0);
ret = clk_prepare_enable(data->ssc_xo_clk);
if (ret) {
dev_err(dev, "error deasserting ssc_xo_clk: %d\n", ret);
goto err_ssc_xo_clk;
}
ret = clk_prepare_enable(data->ssc_ahbs_clk);
if (ret) {
dev_err(dev, "error deasserting ssc_ahbs_clk: %d\n", ret);
goto err_ssc_ahbs_clk;
}
return 0;
err_ssc_ahbs_clk:
clk_disable(data->ssc_xo_clk);
err_ssc_xo_clk:
regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 1);
reset_control_assert(data->ssc_bcr);
err_ssc_bcr:
reset_control_assert(data->ssc_reset);
err_ssc_reset:
clk_disable(data->aggre2_north_clk);
err_aggre2_north_clk:
reg32_set_bits(data->reg_mpm_sscaon_config0, BIT(4) | BIT(5));
reg32_set_bits(data->reg_mpm_sscaon_config1, BIT(31));
clk_disable(data->gcc_im_sleep_clk);
err_gcc_im_sleep_clk:
clk_disable(data->aggre2_clk);
err_aggre2_clk:
clk_disable(data->xo_clk);
err_xo_clk:
return ret;
}
static void qcom_ssc_block_bus_deinit(struct device *dev)
{
int ret;
struct qcom_ssc_block_bus_data *data = dev_get_drvdata(dev);
clk_disable(data->ssc_xo_clk);
clk_disable(data->ssc_ahbs_clk);
ret = reset_control_assert(data->ssc_bcr);
if (ret)
dev_err(dev, "error asserting ssc_bcr: %d\n", ret);
regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 1);
reg32_set_bits(data->reg_mpm_sscaon_config1, BIT(31));
reg32_set_bits(data->reg_mpm_sscaon_config0, BIT(4) | BIT(5));
ret = reset_control_assert(data->ssc_reset);
if (ret)
dev_err(dev, "error asserting ssc_reset: %d\n", ret);
clk_disable(data->gcc_im_sleep_clk);
clk_disable(data->aggre2_north_clk);
clk_disable(data->aggre2_clk);
clk_disable(data->xo_clk);
}
static int qcom_ssc_block_bus_pds_attach(struct device *dev, struct device **pds,
const char *const *pd_names, size_t num_pds)
{
int ret;
int i;
for (i = 0; i < num_pds; i++) {
pds[i] = dev_pm_domain_attach_by_name(dev, pd_names[i]);
if (IS_ERR_OR_NULL(pds[i])) {
ret = PTR_ERR(pds[i]) ? : -ENODATA;
goto unroll_attach;
}
}
return num_pds;
unroll_attach:
for (i--; i >= 0; i--)
dev_pm_domain_detach(pds[i], false);
return ret;
};
static void qcom_ssc_block_bus_pds_detach(struct device *dev, struct device **pds, size_t num_pds)
{
int i;
for (i = 0; i < num_pds; i++)
dev_pm_domain_detach(pds[i], false);
}
static int qcom_ssc_block_bus_pds_enable(struct device **pds, size_t num_pds)
{
int ret;
int i;
for (i = 0; i < num_pds; i++) {
dev_pm_genpd_set_performance_state(pds[i], INT_MAX);
ret = pm_runtime_get_sync(pds[i]);
if (ret < 0)
goto unroll_pd_votes;
}
return 0;
unroll_pd_votes:
for (i--; i >= 0; i--) {
dev_pm_genpd_set_performance_state(pds[i], 0);
pm_runtime_put(pds[i]);
}
return ret;
};
static void qcom_ssc_block_bus_pds_disable(struct device **pds, size_t num_pds)
{
int i;
for (i = 0; i < num_pds; i++) {
dev_pm_genpd_set_performance_state(pds[i], 0);
pm_runtime_put(pds[i]);
}
}
static int qcom_ssc_block_bus_probe(struct platform_device *pdev)
{
struct qcom_ssc_block_bus_data *data;
struct device_node *np = pdev->dev.of_node;
struct of_phandle_args halt_args;
struct resource *res;
int ret;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
platform_set_drvdata(pdev, data);
data->pd_names = qcom_ssc_block_pd_names;
data->num_pds = ARRAY_SIZE(qcom_ssc_block_pd_names);
/* power domains */
ret = qcom_ssc_block_bus_pds_attach(&pdev->dev, data->pds, data->pd_names, data->num_pds);
if (ret < 0)
return dev_err_probe(&pdev->dev, ret, "error when attaching power domains\n");
ret = qcom_ssc_block_bus_pds_enable(data->pds, data->num_pds);
if (ret < 0)
return dev_err_probe(&pdev->dev, ret, "error when enabling power domains\n");
/* low level overrides for when the HW logic doesn't "just work" */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpm_sscaon_config0");
data->reg_mpm_sscaon_config0 = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->reg_mpm_sscaon_config0))
return dev_err_probe(&pdev->dev, PTR_ERR(data->reg_mpm_sscaon_config0),
"Failed to ioremap mpm_sscaon_config0\n");
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpm_sscaon_config1");
data->reg_mpm_sscaon_config1 = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->reg_mpm_sscaon_config1))
return dev_err_probe(&pdev->dev, PTR_ERR(data->reg_mpm_sscaon_config1),
"Failed to ioremap mpm_sscaon_config1\n");
/* resets */
data->ssc_bcr = devm_reset_control_get_exclusive(&pdev->dev, "ssc_bcr");
if (IS_ERR(data->ssc_bcr))
return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_bcr),
"Failed to acquire reset: scc_bcr\n");
data->ssc_reset = devm_reset_control_get_exclusive(&pdev->dev, "ssc_reset");
if (IS_ERR(data->ssc_reset))
return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_reset),
"Failed to acquire reset: ssc_reset:\n");
/* clocks */
data->xo_clk = devm_clk_get(&pdev->dev, "xo");
if (IS_ERR(data->xo_clk))
return dev_err_probe(&pdev->dev, PTR_ERR(data->xo_clk),
"Failed to get clock: xo\n");
data->aggre2_clk = devm_clk_get(&pdev->dev, "aggre2");
if (IS_ERR(data->aggre2_clk))
return dev_err_probe(&pdev->dev, PTR_ERR(data->aggre2_clk),
"Failed to get clock: aggre2\n");
data->gcc_im_sleep_clk = devm_clk_get(&pdev->dev, "gcc_im_sleep");
if (IS_ERR(data->gcc_im_sleep_clk))
return dev_err_probe(&pdev->dev, PTR_ERR(data->gcc_im_sleep_clk),
"Failed to get clock: gcc_im_sleep\n");
data->aggre2_north_clk = devm_clk_get(&pdev->dev, "aggre2_north");
if (IS_ERR(data->aggre2_north_clk))
return dev_err_probe(&pdev->dev, PTR_ERR(data->aggre2_north_clk),
"Failed to get clock: aggre2_north\n");
data->ssc_xo_clk = devm_clk_get(&pdev->dev, "ssc_xo");
if (IS_ERR(data->ssc_xo_clk))
return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_xo_clk),
"Failed to get clock: ssc_xo\n");
data->ssc_ahbs_clk = devm_clk_get(&pdev->dev, "ssc_ahbs");
if (IS_ERR(data->ssc_ahbs_clk))
return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_ahbs_clk),
"Failed to get clock: ssc_ahbs\n");
ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node, "qcom,halt-regs", 1, 0,
&halt_args);
if (ret < 0)
return dev_err_probe(&pdev->dev, ret, "Failed to parse qcom,halt-regs\n");
data->halt_map = syscon_node_to_regmap(halt_args.np);
of_node_put(halt_args.np);
if (IS_ERR(data->halt_map))
return PTR_ERR(data->halt_map);
data->ssc_axi_halt = halt_args.args[0];
qcom_ssc_block_bus_init(&pdev->dev);
of_platform_populate(np, NULL, NULL, &pdev->dev);
return 0;
}
static void qcom_ssc_block_bus_remove(struct platform_device *pdev)
{
struct qcom_ssc_block_bus_data *data = platform_get_drvdata(pdev);
qcom_ssc_block_bus_deinit(&pdev->dev);
iounmap(data->reg_mpm_sscaon_config0);
iounmap(data->reg_mpm_sscaon_config1);
qcom_ssc_block_bus_pds_disable(data->pds, data->num_pds);
qcom_ssc_block_bus_pds_detach(&pdev->dev, data->pds, data->num_pds);
pm_runtime_disable(&pdev->dev);
pm_clk_destroy(&pdev->dev);
}
static const struct of_device_id qcom_ssc_block_bus_of_match[] = {
{ .compatible = "qcom,ssc-block-bus", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, qcom_ssc_block_bus_of_match);
static struct platform_driver qcom_ssc_block_bus_driver = {
.probe = qcom_ssc_block_bus_probe,
.remove_new = qcom_ssc_block_bus_remove,
.driver = {
.name = "qcom-ssc-block-bus",
.of_match_table = qcom_ssc_block_bus_of_match,
},
};
module_platform_driver(qcom_ssc_block_bus_driver);
MODULE_DESCRIPTION("A driver for handling the init sequence needed for accessing the SSC block on (some) qcom SoCs over AHB");
MODULE_AUTHOR("Michael Srba <Michael.Srba@seznam.cz>");