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author | Benjamin Gaignard <benjamin.gaignard@linaro.org> | 2017-01-20 10:15:03 +0100 |
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committer | Lee Jones <lee.jones@linaro.org> | 2017-01-23 12:03:57 +0000 |
commit | d0f949e220fdf5ed1033e9f6e80749b05f2e7b70 (patch) | |
tree | 5b443357a8208a29a75d073ff680d0c671e15607 /drivers/mfd/stm32-timers.c | |
parent | 8f9359c6c6a00b43273480a5cf5b0f240aa3b648 (diff) | |
download | op-kernel-dev-d0f949e220fdf5ed1033e9f6e80749b05f2e7b70.zip op-kernel-dev-d0f949e220fdf5ed1033e9f6e80749b05f2e7b70.tar.gz |
mfd: Add STM32 Timers driver
This hardware block could at used at same time for PWM generation
and IIO timers.
PWM and IIO timer configuration are mixed in the same registers
so we need a multi fonction driver to be able to share those registers.
version 7:
- rebase on v4.10-rc2
version 6:
- rename files to stm32-timers
- rename functions to stm32_timers_xxx
version 5:
- fix Lee comments about detect function
- add missing dependency on REGMAP_MMIO
version 4:
- add a function to detect Auto Reload Register (ARR) size
- rename the structure shared with other drivers
version 2:
- rename driver "stm32-gptimer" to be align with SoC documentation
- only keep one compatible
- use of_platform_populate() instead of devm_mfd_add_devices()
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/mfd/stm32-timers.c')
-rw-r--r-- | drivers/mfd/stm32-timers.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/drivers/mfd/stm32-timers.c b/drivers/mfd/stm32-timers.c new file mode 100644 index 0000000..41bd901 --- /dev/null +++ b/drivers/mfd/stm32-timers.c @@ -0,0 +1,80 @@ +/* + * Copyright (C) STMicroelectronics 2016 + * + * Author: Benjamin Gaignard <benjamin.gaignard@st.com> + * + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/mfd/stm32-timers.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/reset.h> + +static const struct regmap_config stm32_timers_regmap_cfg = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = sizeof(u32), + .max_register = 0x400, +}; + +static void stm32_timers_get_arr_size(struct stm32_timers *ddata) +{ + /* + * Only the available bits will be written so when readback + * we get the maximum value of auto reload register + */ + regmap_write(ddata->regmap, TIM_ARR, ~0L); + regmap_read(ddata->regmap, TIM_ARR, &ddata->max_arr); + regmap_write(ddata->regmap, TIM_ARR, 0x0); +} + +static int stm32_timers_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_timers *ddata; + struct resource *res; + void __iomem *mmio; + + ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL); + if (!ddata) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mmio = devm_ioremap_resource(dev, res); + if (IS_ERR(mmio)) + return PTR_ERR(mmio); + + ddata->regmap = devm_regmap_init_mmio_clk(dev, "int", mmio, + &stm32_timers_regmap_cfg); + if (IS_ERR(ddata->regmap)) + return PTR_ERR(ddata->regmap); + + ddata->clk = devm_clk_get(dev, NULL); + if (IS_ERR(ddata->clk)) + return PTR_ERR(ddata->clk); + + stm32_timers_get_arr_size(ddata); + + platform_set_drvdata(pdev, ddata); + + return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); +} + +static const struct of_device_id stm32_timers_of_match[] = { + { .compatible = "st,stm32-timers", }, + { /* end node */ }, +}; +MODULE_DEVICE_TABLE(of, stm32_timers_of_match); + +static struct platform_driver stm32_timers_driver = { + .probe = stm32_timers_probe, + .driver = { + .name = "stm32-timers", + .of_match_table = stm32_timers_of_match, + }, +}; +module_platform_driver(stm32_timers_driver); + +MODULE_DESCRIPTION("STMicroelectronics STM32 Timers"); +MODULE_LICENSE("GPL v2"); |