[PATCH 09/13 v2] net: ixp4xx_hss: Check features using syscon
From: Linus Walleij <hidden>
Date: 2022-02-11 22:39:37
If we access the syscon (expansion bus config registers) using the syscon regmap instead of relying on direct accessor functions, we do not need to call this static code in the machine (arch/arm/mach-ixp4xx/common.c) which makes things less dependent on custom machine-dependent code. Look up the syscon regmap and handle the error: this will make deferred probe work with relation to the syscon. Select the syscon in Kconfig and depend on OF so we know that all we need will be available. Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: netdev@vger.kernel.org Signed-off-by: Linus Walleij <redacted> --- ChangeLog v1->v2: - No changes. Network maintainers: I'm looking for an ACK to take this change through ARM SoC along with other changes removing these accessor functions. --- drivers/net/wan/Kconfig | 3 ++- drivers/net/wan/ixp4xx_hss.c | 39 ++++++++++++++++++++---------------- 2 files changed, 24 insertions(+), 18 deletions(-)
diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig
index 592a8389fc5a..140780ac1745 100644
--- a/drivers/net/wan/Kconfig
+++ b/drivers/net/wan/Kconfig@@ -293,7 +293,8 @@ config SLIC_DS26522 config IXP4XX_HSS tristate "Intel IXP4xx HSS (synchronous serial port) support" depends on HDLC && IXP4XX_NPE && IXP4XX_QMGR - depends on ARCH_IXP4XX + depends on ARCH_IXP4XX && OF + select MFD_SYSCON help Say Y here if you want to use built-in HSS ports on IXP4xx processor.
diff --git a/drivers/net/wan/ixp4xx_hss.c b/drivers/net/wan/ixp4xx_hss.c
index 0b7d9f2f2b8b..863c3e34e136 100644
--- a/drivers/net/wan/ixp4xx_hss.c
+++ b/drivers/net/wan/ixp4xx_hss.c@@ -16,8 +16,10 @@ #include <linux/hdlc.h> #include <linux/io.h> #include <linux/kernel.h> +#include <linux/mfd/syscon.h> #include <linux/platform_device.h> #include <linux/poll.h> +#include <linux/regmap.h> #include <linux/slab.h> #include <linux/gpio/consumer.h> #include <linux/of.h>
@@ -1389,9 +1391,28 @@ static int ixp4xx_hss_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct net_device *ndev; struct device_node *np; + struct regmap *rmap; struct port *port; hdlc_device *hdlc; int err; + u32 val; + + /* + * Go into the syscon and check if we have the HSS and HDLC + * features available, else this will not work. + */ + rmap = syscon_regmap_lookup_by_compatible("syscon"); + if (IS_ERR(rmap)) + return dev_err_probe(dev, PTR_ERR(rmap), + "failed to look up syscon\n"); + + val = cpu_ixp4xx_features(rmap); + + if ((val & (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) != + (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) { + dev_err(dev, "HDLC and HSS feature unavailable in platform\n"); + return -ENODEV; + } np = dev->of_node;
@@ -1516,25 +1537,9 @@ static struct platform_driver ixp4xx_hss_driver = { .probe = ixp4xx_hss_probe, .remove = ixp4xx_hss_remove, }; - -static int __init hss_init_module(void) -{ - if ((ixp4xx_read_feature_bits() & - (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) != - (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) - return -ENODEV; - - return platform_driver_register(&ixp4xx_hss_driver); -} - -static void __exit hss_cleanup_module(void) -{ - platform_driver_unregister(&ixp4xx_hss_driver); -} +module_platform_driver(ixp4xx_hss_driver); MODULE_AUTHOR("Krzysztof Halasa"); MODULE_DESCRIPTION("Intel IXP4xx HSS driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:ixp4xx_hss"); -module_init(hss_init_module); -module_exit(hss_cleanup_module);
--
2.34.1